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Finn RACON SUPERIOR SPEAKERS Throughout the world leading Sound equip- ment manufacturers have placed all types and makes of horns, speakers and units on exhaustive laboratory test. Engineers in nearly every case have chosen Racon Prod- ucts as being the acoustically perfect, most adaptable sound reproducers for Sound distribution. Whether or not you are satisfied with your present sound reproduction RACON assures you there is still room for improvement. Let us study your problem. Racon's Electro dynamic horn units are recognized as the finest that money can buy. Natural tone quality in any volume with Racon! GIANT ELECTRO Dynamic Horn Unit Continuous operating capac- ity: 7-10 watts. Peak load capacity: 25 watts. No. 6320 Horn, illustrated above, has an air column chamber greater than 10 ft. Depth 37 inches. Bell 76x28 inches. Equipped with cast aluminum throat, patented self supporting frame, bronze coupling. A wide angle horn particularly adapted to distribute sound in theatres of extreme width — 50 feet or greater. Weight 60 pounds. Racon horns and units are covered by U. S. Patents Nos. 1,507,711, 1,501,032, 1,577,270, 73,217, 73,218, 1,722,448, 1,711,514, 1,781,489. I Write for Complete Catalog Racon Electric Co., Inc. 18 Washington Place New York London, England Toronto, Canada Vol. 1, INo. Octoher, 1931 A magazine devoted to better visual and sound reproduction 25e. a < $2.00 a Not a Sound reel — but a projection reel Lightweight, yet sturdy, rigid and durable The Projection Reel Designed by a Projectionist for Projectionists ill O seams, no brazing and no welding to break open or come apart when rewinding or while in the projector. Made of a special aluminum alloy which results in a lightweight yet sturdy and rigid reel. No rough edges to cut the fingers or demage the film. The True Reel for Projection Sold Through Dealers Only PRICES: 15 in. reel with 5 in. hub $3.00 each 11 in. reel with 5 in. hub $2.50 each Manufactured by W. & W. Specialty Co. 159 West 21st St. New York, N. Y. October 1931 INTERNATIONAL PROJECTIONIST Complete rear shut- ter attachments show- ing framing device, shutter adjusting de- vice, framing light, hinged eye shield, cooling plate, fire shutter lever and gate opening device. TWO NOTEWORTHY ACHIEVEMENTS IN PROJECTION EQUIPMENT B. & S. Rear Shutter reduces aperture heat by 70%, minimizes effect of warped and buckled film, and keeps film free from dust and dirt. Exclusive blade feature of this shutter keeps hot air from film and insures constant supply of cool air around the aperture. The results of a test by the Massachusetts Department of Public Safety in a Boston theatre on Janu- ary 19, 1930, are as follows: Without B. & S. Rear Shutter Aperture Heat: 1250° F. With B, & S. Rear Shutter Aperture Heat: 340° to 350° F. Installation can be made in one hour on any single- or double-bearing projector mechan- ism, without any cutting or drilling. Periodic oiling is the only maintenance requirement. Rear shutter equipment includes cooling plate, framing device, shutter timing adjust- ment, and a framing light. A hinged eye shield permits easy accessibility to the me- chanism. B. & S. Change-over consists of two shutter blades contained in a housing de- signed for attachment to the cone of the lamphouse and operates on either A.G. or D.G., at 110 to 125 volts. Novel design eliminates any possibility of double exposure on the screen, and makes the change invisible to the audience. B. & S. Change-overs operate efficiently on either A.G. or D.G., but coils for the proper current will be supplied on specification. Goils of the B. & S. Ghange-over will stand up under heavy overloads and will not burn out. The constant arcing in an ordinary change-over switch soon causes the metal contacts to burn and corrode. All B. & S. switch contacts are made of carbon that cannot corrode. B. & S. unique design also prevents the flash from touching any part of the switch. This switch cannot stick or bind and is positive in operation. B. & S. Ghange- overs have been used for many years in Publix, R-K-O, and other major theatre circuits. BASSON & STERN For fifteen years manufacturers of high grade motion picture equipm^ent 749 EAST 32nd STREET, BROOKLYN, N. Y. INTERNATIONAL PROJECTIONIST October 1931 io Jim f inn: Projectionists of the Home Office and of the Greater New York theatres of Publix Theatres Corporation are glad of this opportunity to express their appreciation of your splendid work in the advancement of motion picture projection generally and in behalf of the projec- tionist particularly. Publix Theatres projec- tionists extend to you their hearty good wishes for success. Publix Theatres Projection Department HARRY RUBIN Director of Projection, Publix Theatres Corporation SAMUEL GLAUBER JESSE HOPKINS Home Office Projection Rooms Ben Negrin Irving Mintz Marion Frejman William Basch Arthur Bell Morris Goldsmith Benjamin Klein Criterion Theatre Projection Staff •Otto Klein Frank Hoffman C. MiUer MAX RUBEN Rialto Theatre Projection Staff Joe Basson Ben Stern Herb Stein Joe Gold William Di Sena David Lazar Morris Paul F. Elkins William Green Brooklyn Paramount Theatre Projection Staff Morris Heller John Hurley Nat Hewitt John Timmerman William Paster William Garbade George Van Deurs Charles Lippman I. Sherman New York Paramount Theatre Projection Staff Harry BergoflFen Richard Kuester William Kelly Meyer Schankman John Harding Oliver de Frietas H. Wickenhaver Samuel Selden Harry Mourier Rivoli Theatre Projection Staff Abe Brenner Howard Paxton J. Bender Max Raskin A. Brower L. Alder Louis Raskin A. Borgman Jack Both wick October 1931 / i( / INTERNATIONAL PROJECTIONIST ^9C1B 131407V 7//nfef/nof//o/na// OjECTK Edited by James J- Finn Volume I I •y OCTOBER 1931 Number 1 Dedication A Letter From the International President Practical Hints on Everyday Pro- jection Problems Harry Rubin Photographic Problems the Solu- tion of Which Would Mater ially Aid Reproduction Lewis W. Physioc Sound System No Better Than Horn and Receiver Units Alli£ Iter A. P. S. Reorganization Problem to Await December Election Out of Frame 11 12 13 14 14 Projection Optics: Three Basic Laws Relating to Lenses 15 Hugo Lateltin Characteristics of RCA Photo- phone Tubes 15 Practical Problems Basis of Acad- emy Program 17 Lester Cowan Local Advertising Should Sell the Craftsman — Not the Labor Unionist 18 James J. Finn Recent Technical Books 19 S. M. P. E. Fall Meeting at S'wampscott, Mass., October 5 to 8 20 P. A. C. Jottings 12 Questions & Answers 22 Editorial Page 23 New Screen Image Table Figured on Basis of Sound-on-Film Aperture 24 Reasonable Care Will Prevent Extraneous Noise 26 Motion Picture Screens — Methods of Selection and Maintenance 27 Francis M. Falge Television News Notes 30 Survey Answers Problem of Re- placement Variations 31 News from the Science World 32 Notes From the Supply Field 33 Patent Page 35 H. L. BURKITT An Open Letter to James J. Finn 36 Miscellaneous Items Technical Hints News Notes Published Monthly by JAMES J. FINN PUBLISHING CORP. 1 WEST 47th STREET, NEW YORK, N. Y. Advertising Manager: H. F. Kendall Yeaiu>y Subscription: United Stales and possessions, $2 (two years, $3) ; foreign countries, $2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Circulation Manager: Ruth Entracht Entire contents copyright, 1931, by . Jfames J. Finn Publishing Corp. International Projectionist is not responsible for personal opi- nions appearing in signed arti- cles in its columns. Cover design by Morgan Bryan. Printed by Roy Press, N. Y. MONTHLY CHAT THOSE buyers who are patting them- selves on the back for the reason that they have successfully avoided buy- ing new equipment or incurred any ex- pense even for repairs for many months back are heading for a fall — and a steep one. A theatre projection room cannot operate efficiently with defective or worn equipment, and if it is being operated under these conditions, the bill will be twice as much some-odd weeks or days or months from now than it would be if the proper action were to be taken now. That projector mechanism that is hum- ming so steadily today may knock and grind and tear itself to pieces tomor- row— and the results will knock the pocketbook harder if the mechanism should decide to quit during a show. Projectionists have no greater respon- sibility than to see that equipments are not permitted to run themselves into such condition that a repair job is out of the question. Most of the penny-wise buyers will shortly face a day of reckon- ing— and what a day it will be! A nominal expenditure of ten-, twenty-, or thirty-odd dollars of today, if left un- spent, can multiply itself into an ex- pense of several hundreds of dollars within a few weeks. And within a few weeks the buck will be passed directly to you, the projectionist, whose job it is to see that such occurrences do not come about. Western Electric is reported to have gone after the matter of replacing storage bat- teries in earnest. Report further has it that in the process of getting "het up" on the subject, W.E. is considering the fol- lowing alternatives: (ll a special recti- fier; (2) coarse filaments which will not respond appreciably to A.C. cycle fluc- tuations, and/or (3) a special optical system which will permit the use of the regulation filament. We will believe in No. 3 if and when we see it (although rumor has it that a Rochester optical company promises to do the trick j ; and No. 2, which we bel- lowed about two years ago, further com- plicates the matter of effective light beam concentration. We like to think of No. 1 as the answer not only because it appears to solve the problem most sat- isfactorily, but also because a question about it nets only blank looks among W.E. men. The A.F. of L. pow-wow at Vancouver in early October will take a vigorous stand for the five-day week. This is fine, and everybody is for it. The fly in the ointment will be Labor's demand for five and one-half days' pay for five days* work. Some fly. J. J. F. INTERNATIONAL PROJECTIONIST October 1931 ANNOUNCING the NEW Amplion OCTOPHASE heavy-duty dynamic unit Employing the dynamic principle invented by Sir Oliver Lodge, the principle of the Piston Diaphragm taught by Edison, Stroh, Cooms, and others, and the principles of sound chamber design contributed by Eichmeyer, Tain tor. Tiger stedt, etc., this unit has a truly brilliant line of antecedents. It would not have been possible without the contribution of these great investigators. It is the contribution of Amplion engineers, working with modern facilities, however, coupled with the experience of the past that has given this unit unprecedented efficiency, wide frequency range, and capacity to reproduce tre- mendous volume with a clarity and tone quality not here- tofore equalled. LEGEND: In the Octophase, the .irea above a scientifically domed piston diaphragm of great rigidity but extreme lightness, is divided into eight divisions with three sections in each division, twenty-four sections in all. Channel ways are provided for conveying the sound impulses from these twenty-four sections to the throat of the horn. Space and time relations are so designed that the impulses from each space reach the throat of the horn at the same moment in perfect synchronism. By means of this construction, there is realized great effi'ciency, greater frequency range and the ability to repro- duce tremendous volume without blasting. Music is reproduced in its full range and speech is reproduced with a finesse that retains every shade of human emotion. From these eight divisions, OCTOPHASE derives its name. The efficiency of this unit is from six to eight hundred per cent greater than that of cone speakers, and is the equivalent of an extra stage of amplification. High sound levels are obtained with less amplification permitting the operating of amplifiers below distortion levels, improving the quality and increasing tube life. Other Amplion Products Are MICROVOX AND TRANSIVOX, PORTABLE PUBLIC ADDRESS SYSTEMS, AMPLIFIERS, MICROPHONES, EXPONENTIAL HORNS, UNITS, Etc. Sound System Apparatus WRITE FOR FOLDER DESCRIBING UNIT AND ACOUSTIC HORNS AMPLION PRODUCTS CORPORATION 38 WEST 2l8t STREET NEW YORK CITY [1 n M 1 C/ r^A erely printing technical data cUfes not justify the existence of a publicatiim purporting to serve a craft. Technical data — yes; but also craft news, a sympa- thetic understanding of the craftsman^s needs at work and away from toork, and c constant vigilance to herald and to fighi any dcmger to either his welfare or hit work — such a service marks the true crafi paper. INTERNATIONAL PROJECTIONIST wU eassy this service — and will endeavor ti attain at least this mark by trying to di more. This is our dedication. JAMES J. FINN INTERNATIONAL PROJECTIONIST October 1931 INTERNATIONAL ALLIANCE OF THEATRICAL STAGE EMPLOYES iiAUxa ^^O MOVING PICTURE MACHINE OPERATORS OF THE UNITED ^^^^ :./J\^ STATES AND CANADA, 1450 BROADWAY. NEW YORK CITY, N. Y. ^fC'Sf Affiliated wM& M* Amtriain FeJtraVon of Labor WILUAM F. CANAVAN, Inlemattonal PratJint FRED J. DEMPSEY. Qeneral Stertlaty'Tteaxurer WILLIAM C. ELLIOTT, First Vice-Preaident, P. O. Box Sll, Cincintiatl, Ohio. WILLIAM P. COVERT, Second Vice-President, tS7 Brock Ave., Toronto, Ont., Can. JOHN P. NICK, Fourth Vice-Prea., Suite Sit, Odeon Theatre Bldg., St. Louie, Mo. WILLIAM J. BARREB, Fifth Vice-Prea., iSH Bryn Mawr Ave., Ardmore, Pa. JOS. C. CAMPBELL, Sixth Vice-Prea., 1818 Linwood Blvd., Oklahoma CitV, Okla. WSI. T. MADIGAN, Seventh Vice-Pres., i9t8 30th Ave., S., Minneapolis, Minn. TELEPHONE PENNwIv.d«{|^5 New York, N. Y.. August 5, 1931. Mr. James J. Finn, International Projectionist, 1 West 47th Street, New York City. Dear Mr. Finn: I desire to "be among the first to extend to you my every good wish for the success of your enterprise. Your work during the past five years in the interests of motion picture projectionists has been of an extremely high order and has earned for you the esteem of the entire craft. The exper- ience thus gained, plus a wide knowledge of the projection field and your oft-demonstrated apprec- iation of the problems of the projectionist, eminently qualify you. for the work which you have elected. I am sure that these personal qualities will he reflected in a splendid publication which will gain, the support of all projectionists. Be assured of my continued interest in your progress. WCrASO BS&AU 12646 Sincerely yours, International President, OCT 20 1931 INTERNATIONAL PROJECTIONIST NUMBER 1 VOLUME I OCTOBER 1931 PRACTICAL HINTS ON EVERYDAY PROJECTION PROBLEMS Harry Rubin DIRECTOR OF PROJECTION, PUBLIX THEATRES CORPORATION PICTURES should be projected without vibration, and should be sufficiently — and evenly — illumi- nated, without brown corners or dark centers. The draw curtains should close in exact time with the ending of each film, the music properly finished on final note. At the beginning of each subject the title should show on closed curtains which are then immediately opened. A blank screen should be carefully avoided. The importance of careful timing, in this work should be strongly emphasized because it is this exactness which adds greatly to the effectiveness of the pro- gram. As one of the audience, you should not be able to distinguish the va- rious change-overs between reels in a multiple reel subject. Both the picture and sound change-overs should be smoothly made. Any one of the foregoing faults men- tioned, if seen on your screen, indicates possible defects in your projection. Screen Illumination For instance, vibration may be caused by insufficient tension, shrunken film, loops which are too short, emulsion de- posits in film traps or tension springs, bent intermittent shaft, bent sprocket or teeth, accumulated dirt on face of in- termittent sprocket, or by transmitted vi- bration from motor or movietone attach- ment, by unstable projector base or pro- jection room floor. A careful check should be made to determine the origin of the vibration. The amount of illumination depends upon: The type of arc used. The make of carbons. The current consumed at the arc. The setting of carbons. The width of shutter blades. Diameter of condensers — Lenses and reflectors. Condition of condensers — Lenses and reflectors. The optical line-up. The length of throw and size of pic- ture. Obviously the projectionist does not have control over all of these factors, but if he shows an interest in his work, he can assist materially in maintaining screen illumination at a maximum value. Even illumination is obtained by hav- ing the proper optical line-up of the arc, the condensers, reflectors and objective lenses, also by carrying a sufficiently large spot on the aperture to avoid brown corners on screen. Defective carbons may vary in com- position or structure, or may chip off, or have faulty cores, all of which results in uneven illumination. Constant attention of the projectionist during the burning of the carbons is necessary, in order to maintain a proper adjustment of the arc. Proper Change-Overs Poor change-overs may be caused by film being missing from ends of reels — this will eliminate a portion of the sound if film-recorded; by projectionist taking the wrong cues to start motor or on film change-over; by throwing the fader over too soon or too late; by failing to take [9] the proper number of "turns down" be- fore starting; by slow pick-up of incom- ing projector, or by improper working of change-over shutter. Poor change-over, starting out of focus or out of frame, destroy the illusion which is being created by the picture and distract the attention of the patrons. In- terruptions of any nature reduce the en- tertainment value of the picture. Inspection Routine To prevent interruptions or reduce them to the minimum and to insure good projection, all film should be inspected for loose splices and other defects be- fore projection. All projectors, lamps, and sound equipment should be regularly and systematically cleaned and inspected. This inspection should determine if the proper tensions and adjustments are maintained throughout the projector mechanisms. If tension of the film is too tight, the film is likely to break; if idler rollers are not properly adjusted, the film will run off sprockets or loose Harry Rubin 10 INTERNATIONAL PROJECTIONIST October 1931 loops and break. Inspection of lamps is necessary to see if insulated parts and all working parts are in perfect condition. Maintaining the proper clearances of pad rollers, fire valve rollers and film trap, and the proper tension on pressure pads and the take-up will (1) extend the life of the mechanism parts; (2) lessen the liability to film fires; (3) conduce to best screen results; (4) reduce wear and injury to film, thereby effecting a tre- mendous saving. Defective Reels Avoiding the use of bent reels will prevent damage to film while in theatre. Inspection and cleaning of mechanism after each reel prevent accumulations of emulsion causing damage to subse- quent reels. Inspection of film after each run will detect loose splices, scratches, or other defects, which may have developed during last run of film. Careful handling of amplifiers is al- lowing sufficient warming up time for tubes, prevention of excessive current in tubes, and when closing down, opening high voltage circuits before low volt- age ones, will prolong the life of tubes. The proper level of sound must be maintained on each subject, and in order to do this, it is necessary that the pro- jectors be periodically tested for equal volume. Spare Parts Stock All parts which show wear should be replaced and repairs made without de- lay. The spare parts should be kept on hand and replacements anticipated. A careful checking of spare parts at fre- quent stated periods against sudden shortage of vital equipment or supplies will eliminate expense of special order- ing or shipping. Duplicates of parts subject to sudden breakage should be readily available in case of emergency. Using manufacturers' code number to designate part ordered wherever possible insures that correct article is received in the first instance. Using stage horns at high volume be- hind closed front curtains invites injury to the horn receivers. Repairs cost $20 per receiver. Careful projectionists guard against this trouble by keeping .volume within limits of receiver. Systematized Work Cleanliness, neatness, orderliness, and systematized work in the projection room are absolutely essential. Since the coming of the sound picture, cleanliness has become particularly important in the projection room. It is literally possible for dirt to be heard as well as seen. Sound reproducing mechanism is so deli- cate and sensitive that it can pick up the smallest speck of dust and transmit it in HARRY RUBIN SAYS: iiinLEANLINESS, neatness, orderliness, and systematized V>4 work are absolutely necessary in the modern projection room. ... It is literally possible for dirt to be heard as well as seen. Sound producing mechanism is so delicate and sensitive that it can pick-up the smallest speck of dust and transmit in the form of distorted sound to your audience* ''The manager who uses good judgment can establish a cooperative spirit which will produce excellent results and maintain friendly relations between the management and the projection staff. Where several men are employed on a sound projection shift, it is necessary that there be a com- plete understanding between the men as to the work \vhich each is to perform. Without such an understanding, some of the work may be neglected as a result of 'letting the other fellow do it', or several men may attempt to do the same work." the form of distorted sound to your au- dience. The sound can be interrupted — or en- tirely killed — through an extremely small speck of dirt which may block the trans- mitted light beams from the exciting lamp or may cause imperfect contacts at hundreds of points in the sound equip- ment. Dirt deposited in the aperture of the projector will show on the screen and divert the attention of the audience. This deposit may be caused by: 1. Dirt picked up on the film through contact with the floor. 2. Dirty projection. 3. Dirty film containers. 4. Lint from cloth used in cleaning film. The careful projectionist will keep the film in a clean condition and keep ex- cess oil from projector, as he knows that oily film attracts dirt and that the oil spots on film show upon the screen; also, oily film affects the quality of the sound. Orderliness demands that all spare parts — kept on hand for use and emer- gencies— be instantly available when needed. Thus delays, if occasioned at all by breakdowns, will be remedied im- mediately, or with the least possible de- lay. For example, an exciting lamp is a very small but very important item. To properly perform its work, it must be placed in the projector and accurately positioned in its holder. In the event of an exciting lamp burning out under proper conditions, it is but a few seconds work to extract this lamp with its holder and insert another lamp and holder, which has been previously focused for this projector. No two projectors seem to have iden- tical focus, and, therefore, each holder should be properly marked and placed near the projector upon which it is to be used. This may appear to be a tri- fling matter but it will shorten the delay to a few seconds should the exciting lamp burn out during the show. Managerial Cooperation The manager who uses good judg- ment can establish a cooperative spirit which will produce excellent results and maintain friendly relations between the management and the projection staffs. Where several men are employed in sound projection it is necessary that there be a full understanding between these men as to the work which each is to perform. They should arrange this in advance so that a smooth performance will be secured. Without such under- standing, some of the work may be neg- lected or more than one man may at- tempt to do the same work. The manager should see to it that there is a full and complete check-up of the projectors and sound equipment every day before the start of the show and also a separate check of each horn unit. Pre-Show Preparation If the manager has an effect machine and magnascope screen, he should use the positive and negative effect designs to dress up his short subjects, seasonal and advance trailers, overture films, organ solos, and introductory titles of features. These positive and negative effect de- signs have become a distinctive feature of the high type of entertainment of- fered in the Publix Theatres. There are, at the present time, approximately 300 of these designs which were originated and created under my supervision. Many artists were employed in the making of them in order to obtain variety — and originality — of ideas and designs. In- asmuch as positive and negative designs are simply combinations of black and white with various shades of gray, the colors are obtained by means of colored gelatines. Considerable thought and ex- perimentation was required before the October 1931 INTERNATIONAL PROJECTIONIST 11 proper balancing of light and shade was obtained which would give the desired effect when combined with color. Machines for showing these designs have been improved at our suggestion so that an effect may be kept on as long s desired without breakage and so that exact registration of positive and nega- tive designs can be quickly made. The Projection Department has issued ad- vice sheets describing those designs and explaining how each was used on which film or other subject, what color com- binations were employed, also other suit- able colors which might be used if de- sired, how masked off and what other effects were used in conjunction, also sug- gestions for the future use of each de- sign. Use of Magnascope With the magnascope screen the man- ager should carefully select the weekly subjects or portions of his feature for such magnascope use. The opening of magnascope creates the illusion of grad- ual enlargement and, therefore, magna- scope should never begin with a title — with this exception: — when the draw curtains are opened on a magnascope screen as at the beginning of a subject. When going from small picture to mag- nascope an appropriate scene must be chosen which conveys spaciousness and secures the best results. Where mov- able magnascope masking is employed it should move smoothly and accurately to position for both magnascope and small picture. Accuracy is required to prevent an excessive overlap of picture on the masking or, on the other hand, to avoid showing blank screen around the picture. The best illusion with sound pictures is obtained when the bottom of the pic- ture is as close to the stage as sight lines will permit. This point should be observed, because sound pictures are really plays, and the players appear more natural when on the level of the stage. Correct Picture Size The size of the picture deserves con- sideration. The size will largely depend on: 1. Sight lines. 2. Distance between the screen and the furthermost seats, and viewing angles. It is not possible to obtain an ideal size for all parts of the theatre, but an average can be found which will be sat- isfactory. The picture should be of suf- ficient size so that the features of the players are easily distinguished from the farthermost seats. The proper type of screen for a wide theatre is one having a diffusive surface. This surface reflects light to the side seats almost as well as to those in the center. A highly reflective surface gives most reflection within a narrow angle, and consequently should be used only in theatres where the pro- jection and viewing angles are small. Care of Batteries Attention given to storage batteries in the matter of maintaining proper level of electralyte and the avoidance of over- charging or over-discharging will result in a full, useful life, and, conversely, a lack of such attention will result in a greatly shortened life, with consequent waste and expense. Failure to keep bat- tery plates covered with electrolyte re- sults in permanent injury to those por- tions of the plates which are left exposed. Over-charging results in the rapid for- mation of sediment which soon short-cir- cuits the cells, and is also wasteful in the use of current. When it is frecjuently necessary to add much water to battery, it may be taken as an indication that bat- teries are being over-charged. Lubricate Frequently Regular and frequent lubrication has a direct relation to the life. of the pro- jector mechanism. Oil should be spar- ingly applied to bearings, and any excess wiped off before projecting film. Ab- sorbent pads should be changed fre- quently, as this will prevent oil soaking into the film amplifier, causing damage to insulation of wires, and also will pre- vent the accumulation of oil on film. Photographic Problems the Solution of Which Would Materially Aid Reproduction Lewis W. Physioc SOUND pictures have greatly affected motion picture photography. The reasons are all very apparent. The cameraman no longer has that freedom and range of activity he enjoyed previously. He has had to make the best of the sound-proof booth and the various other camera covers. They have enveloped his individuality and his artistry in a mat- tress. They restrain the individual management of the camera. There is a very unsatisfactory feeling in having to shoot through heavy plate glass, with its problems of refraction and reflection, personal discomfort, the difficulties of lining up sets and focusing or following focus during the moving shots that seem to have become so popular. Many inquiries have been made as to which type of blimp is most satis- factory. There are no satisfactory blimps. This is the one thing that has taken all the joy out of the cameraman's profession. Indeed, there is little improvement in the "blimp" over the "dog house" (booth), of the earlier days of the talkers. In the booth the disadvantages, as before mentioned, were personal discomfort, shooting through the mediums and the difficulties of focusing, etc., all of which prohibit those little intimacies between the camera and its master. The Aperture: The present picture dimensions are a source of great worriment to the artist. It is very difficult to frame a pretty picture in the present awkward proportions. Vignetting and other individual effects are prohibited by these limited areas and proportions. Projection apertures are not standardized and the cameraman is never sure of his frame. We frequently see the tops of the heads cut off, people partly out of the picture and other awkward instances of framing. We realize the tremendous cost of providing a new aperture, but the present one is certainly unsatisfactory. Even when matted down to the original shape there are many disadvantages, chief among which is the increase of grain by further enlargement. Here, indeed, is another make-shift. Let us realize that if we must make talking pictures, let us make them right. Criticism : What we need very badly is honest, intelligent, constructive criticism. There is nothing so stimulating as criticism — not the caustic, controversial idea so common among reviewers, but competent, analytical disquisitions. We have very little of this. A picture is either a "knock-out" or a "flop": the photography is either good or bad, dull or clear. We want to know why a thing is good or bad. We want to know what to avoid and what fo enlarge upon. Some of us may not relish a criticism of our work, but secretly we will profit by it, for the real student will gather from every source. SOUND SYSTEM NO BETTER THAN HORN AND RECEIVER UNITS IN order to obtain efficiency, a sound reproducing system as a whole must exhibit an even response to all fre- quencies within the audible range. In no element of the system is this need more pressing than in the speaker, or horn, units, which must meet such re- quirements to enable the whole system to produce the desired results. The design of receivers and horns is a matter which has received a consid- erable amount of attention at the Bell Laboratories, and the result of these at- tentions is found in the 555-W receiver and the 16- or 17-type horns. What Is a Receiver? The receiver is a unit which is em- ployed to convert electrical energy into sound energy. The electrical energy is in the form of an alternating current, while sound is a degree of mechanical energy in the form of compressions and rarefactions in the air. It is a simple matter to produce sound energy by mov- ing a diaphragm. It is known now that a conductor carrying a current will tend to move if placed in a magnetic field. Therefore, a coil carrying the electrical energy or speech currents is fixed to the diaphragm and situated in the magnetic field between the pole pieces of a field winding. As the speech current is alternating, the movements of the diaphragm will be of an alternating nature. In addition, the frequency of movement of the dia- phragm will correspond exactly with the frequency of the speech current, and its displacement will be proportional to the value of this speech current. Thus it is possible to convert, faithfully, the elec- trical energy into a mechanical form. Number of Receivers A theatre installation contains one or more receivers depending upon its size. There may be one or two receivers per horn, according to whether a 17-A, 17-B, 16-A or 16-B horn is used, which, in turn, depends upon the size of the installation. The 555-W receiver has a diaphragm made of duralumin 0.002 inch thick. This diaphragm has its central portion eupped, which gives it considerable stiff- ness and causes it to move against the air column with a motion similar to that of a plunger. An ordinary flat diaphragm flexes throughout, and the amount of movement is much greater at the center J. Henry Schroeder than nearer the edge. The diaphragm of the 555-W receiver flexes only near its outer edge, giving considerably better results than the flat type. The speech winding comprises a coil of edgewise wound aluminum ribbon at- tached to the diaphragm, and situated between the pole tips of the field wind- ing. The field winding derives its power from the "H" batteries, consuming 1.5 amps at 7 volts. The speech winding has a high carrying capacity in com- parison to its weight, due to its single layer construction and small amount of insulating material, resulting in a high rate of heat dissipation. The Tone Chamber Immediately in front of the diaphragm is an air space or tone chamber which has to be very carefully designed. The sound radiating efficiency of the horn type of loud speaker may be limited due to interference between air waves as they pass through the chamber between the diaphragm and the throat of the horn. In many types of loud speaker, the di- mensions of this chamber are compara- ble with wave lengths of sound within the audible range. To avoid this, and the resultant irregularities in the fre- quency response, the tone chamber in the 555-W receiver is constructed so that no serious distortion of sound can occur within the useful range of the wave length. An exceptionally high efficiency is ob- tained by using this specially constructed tone chamber and the plunger-like mo- tion of the diaphragm. The efficiency of the unit, for converting power from that of electricity to that of sound, is as high as 50 per cent. When this is compared with the one per cent efficiency of the Drawing showing components of W. E. 555-r receiver [12] average loud speaker, the advances made in this field can be readily appreciated. Importance of Connections It is very important to make sure that the connections on all the receivers are made the same way. If a pair of wires are reversed on a receiver, it will mean that either the excitation current or the speech current will flow in the opposite direction in that receiver relative to the others. This will mean that the dia- phragm of the wrongly wired receiver will be moving in the opposite direction to the diaphragms of the other receivers. In other words, when one diaphragm is compressing the air, the other is creat- ing a vacuum, with the result that one effect neutralizes the other. If the two receivers of one horn are wired in oppo- sition, theoretically, no sound will be heard from the horn. Such an occur- rence, even if the receivers are on dif- ferent horns, will result in the sound dis- tribution being ruined. Some Don'ts If for any reason, such as a blown fuse, there is no field current, very faint sound will be heard. This is due to the residual magnetism left in the poles of the field. Never operate a receiver ex- cept in connection with a horn. The horn provides a long column of air which acts as a load on the diaphragm and prevents it from vibrating so violently as to burst, as it would do if used without a horn. In tliis respect, never raise the fader all out in order to play an exit march through the curtains, or increase the volume for gun shots, etc. Such practice will sooner or later — usually sooner — result in broken diaphragms. Purpose of the Horn The purpose of the horn is to afford a coupling between the receiver unit and the outside air, causing the sound en- ergy, produced at the unit, to be proper- ly radiated into the theatre. The dia- phragm of the receiver will vibrate to the point of self-destruction without de- livering any real amount of sound en- ergy, and it is only by loading it with an air column that we can obtain the de- sired results. The air column must be small in area at the input end to place an appreciable pressure load on the diaphragm, and it must be large at the other end to radiate October 1931 INTERNATIONAL PROJECTIONIST 13 the sound effectively into the free air. For best results the cross sectional area should gradually flare from the small end to the large end, according to an exponential mathematical formula, hence the name of "exponential" horn. In order to effectively handle low notes, the length of the air column must be over half the wave-length of the sound. The 15-type horns have air columns about 14 feet long and are curved for economy of space. Proper Positioning To obtain the maximum amount of realism, the horns are positioned behind the screen and about one-third down from the top of the picture. On an av- erage, the mouth of anyone speaking on the screen is at this position. Different theatres vary enormously with regard to their acoustical qualities, and to obtain the best distribution of sound in all the- atres, it is necessary to deal with each case separately. The flare and tilt of horns are care- fully determined by Western Electric engineers, and under no circumstances should they be altered. Expert acous- tical engineers visit each theatre immedi- ately after installation and then period- ically, in order to ascertain, together with other items, if the quality of re- production and the distribution is up to the standard called for by Western Elec- tric. In replacing the horns after they have been moved, be sure to get them back in position exactly as located by the en- gineers. In order to do this it is advisa- ble to have positioning pins dropping through a portion of the horn towers into holes in the stage. Even a movement of an inch or so from the correct position may result in uneven distribution, and in some theatres, interference of the sound or echoes may be encountered. NEW USE FOR SOUND FILMS A recent report states that novel evi- dence, which may have far-reaching ef- fect, is being tendered in a trial in Mel- bourne, in which a dairy company is be- ing sued for damages because of loud noises which continually disturb the sleep of the plaintiff in the action. A sound recording company was engaged by the plaintiff to record the disturbing noises, and the sound reproduction is to be shown as evidence when the case is tried. Some question arose regarding sound dis- tortion, and the fact that if the film was reproduced in a room the sound would be magnified. The judge is reported to have stated that he would hear the repro- duction and form his own opinions. In obtaining the record, a microphone was placed a few inches from the win- dowsill of the plaintiff's bedroom, and the record was taken, including the reproduc- tion of an ordinary voice for purposes of comparison. ALLIANCE ITEMS Illinois State Organization Meets THE State Organization of Projection- ists convened at Galesburg, 111., Sep- tember 14th, at which time the locals represented decided on an increase in per capita tax, a certain percentage of which sum will apply ot the legislative fund, created in an endeavor to have certain measures and bills introduced at the next session of Congress. The local unions affected fully appreciate the rec- ompense should their efforts meet with success, and are overlooking no possible aid to accomplish their end. Important Work by Florida Council ALL local unions in the State of Flor- ida, with one exception, had proper representation at the meeting of the Florida State Council, held in Tampa, Fla., which was devoted to the discussion of new contracts. Measure was voted upon and passed whereby this body shall be known as above captioned, and will continue to hold periodical meetings. A great deal of time was spent debat- ing on legislation which would be of ma- terial benefit to the various local organ- izations, and it is anticipated that good results will be obtained from the com- bined efforts of the locals working as a unit. New I. A. Local at Nanty Glo, Pa. INVESTIGATION of charter applica- tion for Nanty Glo, Pa., revealed that all requirements specified by the Inter- national Constitution and By-Laws had been complied with. Therefore, proper obligation of members, installation of of- ficers and charter was performed by Sec- retary Lawrence Katz of the Fourth Dis- trict, and constructive information and advice was given for the successful con- duction of the affairs of the new organ- ization. Any Amplifier Equipment Requires I. A. Man ON several occasions it has been called to the attention of the Gen- eral Office that traveling companies have been moving about the country carrying amplifiers, etc., and getting by our local unions without having placed a member of our Alliance. Naturally, when they ar- rive at the next stand and are informed of the International requirements, they relate the position maintained at the pre- ceding point and strenuously protest, feeling that they are being imposed upon. Indifference, neglect or unfamiliarity with the International By-Laws may be responsible for this condition, which was brought to the attention of the Delegates at the Thirtieth Convention in Los An- geles, in the form of Resolution No. 13, which was unanimously adopted. As this type of attraction appears to be increas- ing in number with the advent of the new season, special attention should be brought to bear in an endeavor to strictly enforce the requirements. Resolution No. 13 is herewith re- printed : To THE Officers and Delegates of the 30th Biennial Convention of the I. A. T. S. E. & M. P. M. 0. of the United AND Canada! BE IT RESOLVED, That Article 5, Section 4, Page 55 of the By-Laws, which reads as follows: "Any vaudeville act carrying stere- opticons, spot, flood or effect lamps (such as waterfall, fire, cloud, lightning effects, etc.) or sufficient other electrical appara- tus, shall be required to employ a mem- ber of this Alliance to care for and oper- ate such squipment," be changed to read as follows: "Any vaudeville act carrying public address machines, practical radio sets, amplifying equipment, television appara- tus, stereopticons, spot, flood or effect lamps (such as waterfall, fire, cloud, lightning effects, etc.) or sufficient other electrical apparatus, shall be required to employ a member of the Alliance to care for and operate such equipment." Tenth District Meets in Syracuse A THREE-DAY Convention of the Tenth District, which is comprised of all local unions in the State of New York, was held in Syracuse, N. Y., re- cently. A keen interest was displayed by the attending delegates and many ques- tions of mutual interest were discussed. The problem of dual organizations re- ceived considerable attention, and the District went on record to assist any lo- cal within the District who found them- selves troubled by such organizations. /. A. Executive Board Meets at Vancouver IN accordance with the usual custom, the General Executive Board of the International Alliance of Theatrical Stage Employes and Moving Picture Ma- chine Operators of the United States and Canada held sessions in conjunction with attendance at the American Federation of Labor Convention, which convened at the Vancouver Hotel, Vancouver, B. C. on Monday, October 5th, 1931. All Charges and Appeal cases handled by the General Office subsequent to the Gen- eral Executive Board meeting of last July, were submitted to the Board for consideration, as well as all other mat- ters requiring immediate attention. 14 INTERNATIONAL PROJECTIONIST October 1931 A. P. S. REORGANIZATION PROBLEM AWAITS DECEMBER ELECTION NEGOTIATION between West Coast chapters and the Supreme Chapter (N. Y.), of the American Projection So- ciety looking toward a settlement of the matter of reorganization, proposed by the former group, has been suspended, it has been learned from a usually well- informed source. Report has it that the New York contingent favors letting mat- ters stand as at present until the annual election of officials scheduled to be held in December. The West Coast chapters, on the other hand, desire immediate ac- tion so that the affairs of the Society, al- ready seriously disrupted by the talk of reorganization, may be placed in order without further delay. West Coast chapters have long favored reorganization of the Society but did nothing to bring it about until June of this year when they sponsored a series of meetings held in Los Angeles which re- sulted in the passage of a resolution cit- ing the "managerial inefficiency" of the Supreme Chapter and calling for reor- ganization of the Society. This resolu- tion had the approval of the following chapters: No. 7, Los Angeles; 11, Van- couver, B. C; 12, Oakland; 16, San Francisco; 19, San Bernardino, and the organized but as yet unnumbered chap- ter in San Diego. The West Coast group is standing firm on the content of the aforementioned re- solution. The New York faction has held several meetings within recent weeks, the last being on October 1, as a result of which they are reported to have decided to make certain "concessions" to the Coast chapters. The nature of these con- cessions could not be definitely estab- lished, but it has been learned that one of them will involve the transfer of pub- lication offices of The American Projec- tionist, official organ of the Society, to the Coast, probably to Los Angeles. Other than this, nothing could be learned except that the New York group is "kindly disposed" toward the Coast chap- ters and is willing to "cooperate" in "any action looking toward betterment of the Society as a whole;" also that the elec- tion of officers in December is "expected to provide the answer to the whole prob- lem of reorganization." It appears extremely doubtful that the West Coast chapters will regard direc- torship of The American Projectionist as any considerable "concession" to them, and they are expected to press for the right to exercise control over and direc- tion of the Society as a whole. Failing this, it has been intimated, the Coast chapters may consider secession. It is more or less an open secret that many other chapters of the A.P.S. are in complete agreement with the stand taken by the Coast chapters, and that reorgan- ization of the Society at an early date is earnestly desired— even by those chap- ters which have heretofore maintained very close relations with the New York group. If the whole matter should even- tually come to a "showdown" of votes in a general election, the Coast chapters are expected to win easily. For this reason, say some observers, the New York group is now eager to make certain concessions to forestall certain defeat. It seems netirely probable that nego- tiations between New York and Coast chapters designed to reach some amica- ble agreement on controversial points will be reopened prior to election time in December, so that whatever the out- come of the balloting, a continuation of the Society's activities by all chapters will be insured. DE FOREST RECEIVES $1,000,000 IN TUBE SUIT SETTLEMENT C. G. Munn, President of the DeForest Radio Company, announces that the triple damage suit against Radio Cor- poration of America has been settled by the payment to DeForest of $1,000,000 in cash, and that cross license agreements on tube patents only have been entered into by both companies. This settlement brings to a close the litigation of several years over the so-called Clause 9 of the contract by the RCA with its receiving set patent licensees, whereby said li- censees were limited to the use of RCA or RCA licensed radio tubes in their sets. The DeForest Radio Company, as well as other independent radio tube manu- facturers, contested the legality of Clause 9, winning a succession of court decisions. "The settlement of our triple damage suit against the Radio Corporation of America at this time is of far-reaching importance not only to the DeForest Radio Company but to the sound re- production industry at large," states C. G. Munn. "The settlement has been hastened by the recent decision of the Supreme Court, holding the Langmuir patent invalid. That patent, which has been held as a threat against the radio industry and other industries utilizing the high vacuum tube, is not included in the present settlement. Even if the pre- vious decision should be reversed on the appeal, the DeForest Company would have full rights under the Langmuir patent by virtue of the cross licensing agreement now consumated with RCA. "The radio public gains by this settle- ment through having the radio industry concentrate once more on the develop- ment and production of new and better radio products, in place of the long liti- gation which has severely strained the resources and attentions of the con- testants during the past few years." OUT OF FRAME By Opti Collusion ELIEVE it or not, a chief projection- ist does not project a picture. A chief projectionist should not be con- fused with a Supervisor of Projection, the difference being that the latter visits the projection room not more than twice a year. Don't bother to take home any samples of grease graphite, boys. It may be all right on take-up chains and as a lubri- cant for your hi-le, hi-lo lamps, but ex- perience has proven that it is not very gopd as a toothpaste. • . . . and don't take the sound amplifier home after the show. All fight broad- casts terminate at 10.30 p. m. • The last time I warmed my lunch in the lamphouse, the soup boiled over and spoiled a perfectly good mirror which up to that time had only one crack. • The trouble with the paying patron is that he hasn't sufficient patience to wait until I do a good vulcanizing job on an inner spare tube — between reels, of course. « Have you heard from your manager yet regarding how to stretch carbons? • Well, in the absence of a 30-amp. fuse, why not three lO's? How to save oil: deposit it in a bank. Film cement is cracked condensers. g. for patching If a wall breaks down on a record, build a new wall or dig a new groove. A penknife will work well on this. Woolworth's tools are unsurpassed for projection work. Vaseline makes a fairly good cup grease. It is not so good as a lens paste. Newspaper, or even tissue in a pinch, will clean any lens. Try it. The next time the "chief" tells you how he would do it, ask him to demon- strate. PROJECTION OPTICS: THREE BASIC LAWS RELATING TO LENSES SOME few years ago projection op- tics was a subject to which the projectionist in the average the- atre could devote his serious attention or not, at his discretion, and still not have his work be sub-standard. Optical prob- lems then were comparatively simple: beyond a careful handling of lenses and mirrors while cleaning them and a prac- tical knowledge regarding focusing, lit- tle other knowledge on the subject was required in a theatre with the usual equipment of two projectors. The construction of projection lenses has remained unchanged since the in- troduction of motion pictures, the Petz- val type lens, developed nearly a cen- tury ago, having been adhered to until recently. An additional factor in op- tical problems was the simple construc- tion of lenses permitting their use by pro- jectionists who did not possess any theo- retical knowledge of the underlying principles of optics. As a result, a ma- jority of projectionists had simply a "working knowledge" of lenses and it was on this basis that they did their work. The work of the projectionist, with few exceptions, consists of oft-repeated exe- cutions of particular manual operations. True, some of these operations are rather complicated and require intensive train- ing, but there is not a single phase of projection work which lies beyond the capabalities of the projectionist who manifests an inquisitiveness about every and anything pertaining to his work. While it is true that a projectionist may "get by," as the saying is, with merely a working knowledge of his craft, manual skill alone will not enable him to dis- charge his duties competently. Investi- Hugo Lateltin gation and study of the various aspects of his work is needed; and it is really surprising to note the new outlook on the profession of projection that comes with a deep interest in the finer points of the trade. Today a mere working knowledge of the trade will not suffice. Theatres are equipped with modern optical devices and with effect machines, the proper op- eration of which demands both a theo- retical and practical knowledge. One without the other renders useless either of these qualities. Projectionists should know not merely "how" but also "why." Merely operating a machine without a proper understanding of the principles underlying its operation can hardly be termed a profession. The operation of an effect machine de- mands at least a working knowledge of optics. The projectionist should be able, while working on new combinations for a desired effect, to definitely calculate in advance the proper optical arrange- ments, thus saving himself a great deal of experimental labor and his employer the cost thereof. Apart from these con- siderations, which are of major impor- tance, the projectionist himself will de- rive much satisfaction. It is the purpose of this article not to explain the laws relating to but to cite the underlying principles of optics which are necessary in order to afford the aforementioned working knowledge. We shall explain herein cer- tain fundamentals which may be termed the tools of the trade for the projection- ist, insofar as his work is concerned with optics. These fundamentals are: 1. The point to point method which enables one to trace the course of the light rays through the lens. The most simple means of gaining an understand- ing of the nature of a lens consists of tracing the light rays from a point of the object (aperture, slide, etc.), to its cor- responding point on the screen. This is accomplished by using only two rays of light emanating from a particular point. One ray travels parallel to the optical axis and is deviated by the lens toward the principal focus of the lens; the other ray passes through the exact center of the lens without deviating. The accom- panying diagram illustrates the course of two such rays. In addition to the two rays emitted at a point on the aperture, slide, and the like, innumerable other rays pass through every point of the lens and finally merge on the screen at the same point where the two rays previously mentioned came together. 2. The fundamental working knowl- edge of every projectionist is represented by the formula: 1 1 _ J_ a b f This formula states that the reciprocal of the distance a from the object to the lens, added to the reciprocal of the dis- tance h from the lens to the screen, is equal to the reciprocal of the focal length of the lens. With this formula at hand we are able to determine the necessary focus of a lens in order to produce a picture at a certain distance. The focus of a lens depends, according to the above formula, on the distance from object to lens and from lens to screen. These distances depend, on the other hand, on the magnification of a cer- tain objective. This magnification ratio is contained in the following formula: Size of object M = Legend: F — focus; Pi — a point on the aperture; P. — a point on the screen. [15] Size of image b 3. M, representing the ratio of the ob- ject (aperture, slide, etc.), to the size of the picture on the screen, is equal to the ratio of the distances a and b. In an actual case of determining the focus of a lens, we proceed as follows: First measure the size of the object, and then determine the particular size of picture desired. The ratio between the object and the picture will represent M, the magnification ratio. Second, measure the distance from the object to the point where the screen is, or is to be placed. 16 INTERNATIONAL PROJECTIONIST October 1931 This distance is the sum of the distances a and b, and their lengths are found through the formula a M = b Insert the length of these distances in the following formula: f a b \ and you will thus be able to find the exact focal length necessary to produce a certain size picture at a certain dis- tance from the object. This fundamental working knowledge will definitely enable us to cope with optical problems incident to our profes- sion and will lead us to an understand- ing of the basic nature of the lens. Both will be useful, the first in the practical application, and the second in a height- ening of the understanding which leads to a real interest in our profession. Examples : No. 1. With a slide which is 3" high, and at a projection distance of 100 feet, we desire to project a picture 15 feet high. What focal length lens will be necessary? Given: Slide height, 3"; picture height, 180"; projection distance, 1,200." height of slide a M = = or height of picture 3 a M = = 1 f + 180 1,200 3 X 1,200 = 20 1 180 1 1 -\ or a b f 1,200 + 20 20 1,220 24,000 1,200 24,000 24,000 f = == 19.67", answer 1,220 No. 2. A film is projected through an aperture 0.6" high at a projection dis- tance of 100 feet, and we desire to pro- ject a picture 15 feet high. What focal length lens will be necessary? Given : Aperture height, 0.6"; picture height, 180"; projection distance, 1,200". height of aperture a M height of picture 0.6 a or M = 180 1,200 0.6 X 1,200^ 180 1 = 4 1 f 1 a + - - = b f 1,200 + 4 1,204 4,800 1,200 4,800 4,800 f = = 3.98", answer 1,204 Characteristics of RCA Photophone Tubes With explanatory notes covering their use in all types of RCA equipment Equipment Amplifier Radio- trons Filament Voltage Grid Voltage Plate Voltage Plate Current (ma.) Remarks PG-3, 4, 6, 7& 8 PA-12A UX-210 6 — 9 135 3 1. Voltage amplifier using 6 Radio- trons UX-210 connected in 3-stage push-pull circuit. Battery power. PK-1 UX-250 UX-281 7.5 7.5 —84 450 55 75 2. Power amplifier using 2 Radio- trons UX-250 in single push-pull stage with 2 UX-281 's to furnish plate and grid voltages from A. C. supply. PG-10 PA-12B UX-112A 5. — 9 135 3.1 3. See remarks No. 1 above, except as to type of tube. PK-1 UX-250 UX-281 7.5 7.5 —84 450 55 75 4. See remarks No. 2 above. PG-13 PA-41 UX-112A UX-112A UX-112A UX-250 5 5 5 7.5 — 9 — 9 —13.5 —85 115 115 149 425 3.1 3.1 2.7 35 5. Voltage and power amplifier using 3 voltage amplifying stages with single UX-112A in each, fol- lowed by a power stage using 4 UX-250's in a push-pull parallel cir- cuit; D. C. power from a 3-unit M. G. set. PG-28 PA-67 UY-224* UY-227 UX-245 2.5 2.5 2.5 —1.4 —8 —46 155 140 245 2 4 30 6. Voltage and power amplifier of 3 stages using 2 UX-245's in push- pi 11 in the power stage; completely AC-operated. UX-280 5 42-50 6a. -42 ma. in PA67A1; -50 ma. in PA67A3. PG-30 PB-23 UY-224 1 UY-227 ■ UX-245 UX-280 2.5 2.5 2.5 5 —0.6 —6 —44 180 100 220 1 3.5 30 40 7. Voltage amplifier of 3 stages using 2 UX-245's in push-pull in the output stage; completely AC- operated. PB-24 UX-250 UX-281 7.5 7.5 —75 435 45 67 8. Power amplifier using 2 UX-250's in push-pull; completely AC-oper- ated. Notes: *Has a screen voltage of 62; t has a screen voltage of SO. [This table prepared exclusively for Interkationai, Projectionist] October 1931 INTERNATIONAL PROJECTIONIST 17 PRACTICAL PROBLEMS BASIS FOR ACADEMY PROGRAM Lester Cowan EXECUTIVE SECRETARY, ACADEMY OF M. P. ARTS AND SCIENCES PRACTICAL studio problems and correlation between studio and the- atre practices have formed the basis of the Academy technical program during the summer months. In addition to the projects delegated to sub-committees by the Producers-Technicians Committee a number of conferences of studio and the- atre technicians have been held on prob- lems which may be approached through a cooperative effort by the various units of the industry during the winter months. A summary of the more important work of the individual committees and the Academy Technical Bureau since the last Bulletin includes a wide range of activities : Standard Apertures Specifications for standard camera and projector apertures in three by four pro- portions are now being worked out from data supplied by the studios, laborator- ies, and equipment manufacturers. Spe- cifications are to be presented to the stu- dios within the next week, for study and decision. The proposal is a second step in the standardization of apertures begun by the Academy in 1929. It is made pos- sible now by the decrease in the use of sound-on-disc and the increasing number of theatres restoring the 3x4 propor- tions from movietone pictures by a re- duced proportional aperture and shorter focal-length lens. Conferences of studios representa- tives have been held at which it was agreed that if other considerations in the industry will permit the establishment of a new standard, considerable savings can be effected in the studios. Estimates indicate that standardizing of apertures would save from a half -hour to an hour a day production time on every set now being spent in setting up cameras, lights and microphones to allow for the dead picture area on the film. Lights and microphones could be dropped from three to five feet lower, and as much as six feet can be cut off the top of large sets. Sets could also be reduced in width. Specifications allowing the necessary tolerances for the various processes in photography, printing and projection are being worked out by a sub-committee consisting of Virgil Miller, Joe Dubray and George Mitchell. A conference of executives of nine studio sound depart- ments has determined on sound track re- quirements. Other data is being secured from laboratories and manufacturers of projection equipment. Standard Release Print Results of the national survey of repre- sentative projectionists has been com- pleted, strongly supporting the Standard. To date 650 questionnaires have been re- turned from 46 states and Canada in- cluding replies by 120 local union secre- taries, so that the survey covers about a thousand theatres of all classes. Meetings of the sub-committee and of groups of projectionists have been held and the survey questionnaires have been thoroughly studied. The committee also secured special engineering surveys by E.R.P.I. and RCA Photophone. From this data only a few minor changes have been shown to be desirable. As projectionists should now be ac- customed to finding the changeover sig- nals, the sub-committee is planning to recommend a slight reduction in the size of the cues. Other minor revisions of the specifications are under consideration and will be announced in the near fu- ture. S.M.P.E. Approves S.R.P. The following resolution has been re- ceived from the Projection Practice Com- mittee of the Society of Motion Picture Engineers. This committee is chair- maned by Harry Rubin, who has been active in the work of the Projection Ad- visory Council supporting the Standard. WHEREAS, the Standard Release Print has been in widespread use during the past several months and has resulted in the reduction of film mutilation and the elimination of punch-marking of film for change-over purposes, AND WHEREAS, the Standard Release Print has contributed to improved change-overs and smoother perform- ances ; THEREFORE, be it resolved that the Projection Practice Committee go on record as endorsing the said Standard Release Print as a practical step in the improvement of projection. Film Processing The Film Processing Committee chair- maned by M. C. Levee is working toward determination of desirable standards in processing and quality. Replies have been received from nearly all the studios to an exhaustive ques- tionnaire covering all phases of film pro- cessing methods and standards. These replies have been tabulated and studied by a sub-committee consisting of W. C. Harcus, Wesley C. Miller and C. Roy Hunter. A comparison of the gamma and density scales in use at different la- boratories is now being carried out for the sub-committee by Dr. John C. Frayne of Electrical Research Products, Inc. Camera Silencing The Producers-Technicians Committee several months ago authorized that meas- ures be taken to stimulate camera manu- facturers toward developments to make the present clumsy and expensive camera blimps unnecessary. Cameramen are uni- formly opposed to blimps and blame them for slowing their work. A suf- ficiently silent camera would make pos- sible great savings in time on the set. A series of surveys, manufacturers con- ferences and sub-committee meetings have been conducted on this project. Through these the main difficulties in the way of a silent camera have been brought out and information supplied the manufacturers as to requirements common to all studios. REASONABLE CARE PROLONGS LIFE OF VACUUM TUBE THE life of a vacuum tube is greatly reduced if the filament current is too high. The reason for this is that an overheated filament throws off electrons at an excessive rate, and the oxide coat- ing, which supplies most of the electrons, therefore becomes rapidly exhausted. When a filament is near the end of its life, a weak spot usually develops which glows more brightly than the remainder. Whenever a tube begins to show this symptom it should be replaced by a new tube from the spare stock. If the fila- ment current is too low the tube will not be harmed, but the system will not de- liver proper volume and the quality may be impaired, therefore, always carefully regulate the filament current to the value specified by the maker. In some amplifiers, two or more va- cuum tubes are operated with their fila- ments in series; if one of the tube fila- ments burns out the others will also be extinguished. It is advisable for every projectionist to study the schematic of each amplifier, so that he will be familiar with every possible condition when trouble is encountered. "KELDUR" DISTRIBUTION "Keldur," anti-vibration material which is finding wide application in the motion picture industry, is now being distributed in the East by Steinmetz & Co., with of- fices in New York and Philadelphia. The New York office, at 30 Church Street, is under the direction of R. G. Hess. LOCAL ADVERTISING SHOULD FEATURE THE CRAFTSMAN— NOT THE LABOR UNIONIST James J. Finn THE idea of advertising the trade unionist is decidedly not new. Labor has many times come off second best in its encounters with capital, repre- sented by the large corporations in Amer- ica and elsewhere, and that intangible something known as "public opinion," n\olded by capital through the medium of publicity into falling in with its way of thinking, usually figured largely in deter- mining the final result. Capital early learned the monetary va- lue of intelligent publicity, particularly in its encounters with labor; but labor, simulating that "old dog," was slow to learn new tricks. This undoubtedly was due to the resistance of the labor leaders, most of whom were (and still are) , of the so-called "old school." And even when it did take its cue from capital and adopt modern methods of shaping public opi- nion, labor quickly demonstrated its in- eptness for the tools with which it was working. , , A classic case in point is that of the cigarmakers' union — the best advertised labor organization in the world. A few years ago one could not travel any ap- preciablie distance — afoot, by automobile, or by train — without being confronted with an advertisement of the cigarmakers' union. Great stuff, this advertising. Great. . . . What is the status of the cigarmakers' union today? Some say that machines accomplished the rout of the cigarmakers; and undoubtedly they had a lot to do with the disintegration of this organization. But even so, the per- centage of union made cigars in relation to the total amount sold today is so small as to be almost negligible. The answer is not difficult to find. But more of this later. Little Iii^provement Today Today sees little improvement in la- bor's approach to this problem. True, there is a plentitude of labor union ad- vertising— in labor papers, pamphlets, handbills, house organs, by pickets, and, lately, by radio. But withal, labor still is ignorant of how to properly go about the job. So much for labor union advertising in general. Of particular interest here is the rapid spread of localized advertising among Units of the International Alliance. Here is a group of unions which doesn't have to be "sold" on the idea of advertising themselves. Why, they literally fell in love with the idea. Now a large number of local unions are advertising; and the promoters of various enterprises all are enjoying a crack at the local union treas- uries— the printers, the artists, the paper houses, the button manufacturers, the banner makers, and the radio, particu- larly the latter. Overlook 'Selling Point' Advertising is fine. Everybody knows the writer is a firm believer in advertis- ing, and the more the merrier. But, seri- ously, it occurred to the writer as one who is merely an observer on the sidelines that now is the time to pause and give some thought to the character of this la- bor union advertising. What kind of ad- vertising is it . . . and does it get results? We doubt it. Of all the advertising by International Alliance local unions that we have seen, only one or two specimens may be said to have reflected any understanding of the primary purpose of advertising — to create a demand for something, to sell something. Advertising a labor organiza- tion is an attempt to create a demand for a commodity just as definitely as is the advertising of any mercantile organiza- tion. But these latter merchants display common ordinary horsesense in that they advertise their product; while labor unions make the fatal mistake of advertis- ing not their product but their organiza- tion, with particular stress on the fact that it is a labor organization. Those to whom all this labor union ad- vertising is directed are not interested in labor organizations — they don't want to Food for Thought — The average experience of the members of our union is 15 years 5 months. UNION operators have experience. Skill and Care Insure Safety The base of motion picture film is gun cotton. It is not explosive but it is highly inflammable. Care is required to prevent the heat generated by a light of many thousand candle-power from igniting it. Union operators are careful. WHEN PURCHASING THE- AXRE TICKETS BE SURE THAT YOU RECEIVE THIS EXTRA PROTECTION TO WHICH YOUR MONEY ENTITLES YOU. ASK TO SEE THE UNION EMBLEM AT THE BOX OFFICE. UNION SEAL SILENTLY, SAFELY WE SERVE YOU MOVING PICTURE OPERATORS UNION NO. 250 Affiliated with the American Federation of Labor An example of intelligent newspaper advertising by Salt Lake City L. U. No. 250 [18] October 1931 INTERNATIONAL PROJECTIONIST 19 buy the organization. But they are inter- ested in what the labor organization has to offer, to sell them : better quality work not primarily because of the organization but because of the better craftsman who is a member of that organization. Sell the craftsman, not the organization. This is what is the matter with labor union advertising; this is what our friends the cigarmakers overlooked; and this is what countless other labor unions are doing today to waste the money of their members: they concentrate their attention upon selling union labor, in which practically nobody is interested, and neglect almost wholly to stress the one point that is a selling point, and that the quality work produced by its member craftsman. In the motion picture business, in which we are particularly interested, the public is buying entertainment. Natu- rally it is important whether the great theatregoing public can be entertained in pleasant surroundings and without being annoyed by distractions as a re- sult of inferior work, and without having to think about the consequences of inade- quate safety measures. International Alliance local unions have just two things to sell this vast army of theatregoers: (1) better work by a craftsman who knows his job, and (2) absolute safety which is guaranteed by this same craftsman who through proper training and long experience may be counted upon to so do his work that no safety factor is slighted. The local union merely as a labor organization cannot give assurance on either of these points; but the craftsman member of the organi- zation, by virtue of his standing as a craftsman, is assurance that his work — in this case, projection work — will be done competently and with a maximum of safety. The organization can merely brag about its better craftsmen. But do they? Not at all. The lino-, types click, the presses roll, words pour forth from loudspeakers and banners scream their messages from points of vantage — and serve only to inform the public that a labor organization demands work merely because it is a labor or- ganization. Complete data relating to the organi- zation is given: when it was organized; how many illustrious leaders it has had; how many of its members fought in the World War; how much money its mem- bers spend in the town ; the present pres- ident's name (usually in large red letters occupying about half the available space) — but not a word relating to why its mem- bers are better craftsmen. Let there be a complete about-face on this matter of advertising the labor union. Let the craftsman have all the glory; after all, he is the organization. Tell the story of why the organization member is a superior worker, and let the organization enter into the matter only for the reason that it insists that its members be proficient. The job can be done right. Accompanying this article is just one sample of intelligent adver- tising in this direction. Many more could be shown, but this one specimen will convey the general idea. Forget the organization. Sell the craftsman. Recent Technical Books Recording Sound for Motion Pictures, edited by Lester Cowan for the Acad- emy of Motion Picture Arts and Sciences. A compilation of 24 papers by as many writers. 24 chapters, 419 pages, including glossary and index. Profusely illustrated. Published by McGraw-Hill Book Co., New York. Price $5.00. 9^4 x 6. The story of sound motion pictures from the technical standpoint is con- tained in this book, a compilation, under the editorship of Lester Cowan, of twen- ty-four papers written by technicians who played an active role in the development of the technique of sound recording and reproduction. Some of the papers in- cluded herein were previously released in the Technical Digest of the Academy of Motion Picture Arts and Sciences and were printed in the various trade and technical publications. "The Ancestry of Sound Pictures," by H.-G. Knox, and "The Nature of Sound," by A. W. Nye serve as introductory chap- ters to the following main divisions; "Sound Recording Equipment," "The Film Record," "Studio Acoustics and Technique," and "Sound Reproduction." Following these divisions is a glossary of technical terms and a very useful index. There can be no question that this volume is authoritative, as each writer is an acknowledged expert in his particular work. These gentlemen knew their theory before they attempted the sound picture job; and in doing the job they quickly reconciled theory with practice. Their experiences are set down in this volume. Nothing more need be said by way of recommendation. This is the one book which reflects a proper approach and a finished execution in the compilation of technical data relating to the sound pic- ture. Every serious worker in the art, as well as those who are interested in any way in sound pictures, should have a copy of this book. Recommended un- reservedly. Television, Its Methods and Uses, by Edgar H. Felix. 272 pages, illustrated, with index. Published by McGraw- Hill Book Co., New York. Price $2.50. 51/2 X 8. This is the first really practical book on television that has come to our notice. The "low-down" on the art is given here- in, and in such a manner as to provide a refreshing contrast to the conventional expositions of the subject. Mr. Felix has the happy faculty of making a com- plex subject appear relatively simple, a characteristic which marks all his tech- nical writings. This, his latest book, is written in a style that smacks of fiction and maintains the reader interest from start to finish. The novice as well as the trained television worker will find this volume valuable. We think it fortunate for the television art that Mr. Felix has written this book. Cutting through the mass of over-enthu- siastic publicity releases, he has pierced the core of the subject and given an ac- curate picture of the status of the art to- day. He tells in a remarkably straight- forward manner the shortcomings of the art, which are many, and displays neither fear nor favor in enumerating the vari- ous factors which have militated against this baby science. Mr. Felix feels that "'a conservative attitude is particularly helpful at this time, because television lias been treated to an excess of prema- ture and unwarrantedly hopeful pub- licity." He who would know the "how" and "why" of television should have this book. Projecting Sound Pictures, by Aaron Nadell. 265 pages, 100 illustrations, with index and chapter questions and answers. Published by McGraw-Hill Book Co., New York. Price $2.50. 6 a: 9. It is to be regretted that Mr. Nadell did not write this book shortly after the "first flush" of sound motion pictures, when projectionists were eagerly search- ing for such data, for if he had. his work today would be the standard by which all similar efforts would be judged. As it is, much of the force of the book is lost for the reason that the same ground has been worked over not once but many times by other writers who. while prob- ably not possessing the ability Mr. Nadell does, have done reasonably well in their efforts; This Nadell book is good — very good — but it is questionable whether in the light of the foregoing statement, it will exert any particular appeal among projectionists. Mr. Nadell concerns himself largely with theory, yet in such a manner that the "meat" of his story emerges vividly clear-cut. This does not imply that this work has neglected the practical side of the question, for Mr. Nadell proceeds from theory to practice with considerable ease, and combines both elements in an understandable whole. Long experience in the reproduction field, in addition to an apprenticeship with Electrical Re- search Products, have eminently qualified Mr. Nadell for his task, and the knowl- edge thus gained is reflected . in this work. James J. Finn. S. M. P. E. FALL MEETING AT SWAMPSCOTT, MASS., OCTOBER 5 TO 8 THE annual Fall meeting of the So- ciety of Motion Picture Engineers will be held at Swampscott, Mass., October 5 to 8, inclusive. The New Ocean House will be the headquarters for the Convention. The Papers Com- mittee has announced a program of more than fifty papers for this meeting, at- tendance at which is expected to be swelled by many who could not attend the last meeting on the West Coast. The Swampscott meeting will mark the retirement of J. L. Crabtree as Presi- dent of the Society. Dr. A. N. Gold- smith, Vice-President and Chief Engi- neer of the Radio Corporation of Amer- ica, and Dr. V. B. Sease, Director of Hesearch, Du Pont-Pathe Film Manufac- turing Co., have accepted their nomina- tions for President. E. I. Sponable, Di- rector of Research and Development, Fox Film Corporation, and M. W. Palmer, Electrical Engineer, Paramount-Publix Corporation, are the nominees for Vice- President. Nominations for Offices Other nominees are as follows: J. H. Kurlander, Commercial Engineer, West- inghouse Lamp Co., and R. E. Farnham, Commercial Engineer, General Electric Company, for Secretary; H. T. Cowling, Eastman Kodak Company, and W. B. Little, Engineer in Charge of Pho- tometry- Electrical Testing Laboratories, for Treasurer; L. C. Porter, Dluminating Engineer, General Electric Company; W. H. Carson, Vice-President, Agfa- Corporation; W. B. Rayton, Director of Scientific Bureau, Bausch and Lomb Op- tical Company; and 0. M. Glunt, As- sistant Director of Apparatus Develop- ment, Bell Telephone Laboratories, for members of the Board of Governors. These nominations has occasioned no little surprise among that element of the Society membership which long has held that the Society was fast losing its origi- nal character as a motion picture organi- zation through the medium of selecting officers and members of the governing body who are not strictly motion picture workers and in permitting a large por- tion of its papers programs and interest to be devoted to subjects not of general appeal to the motion picture field. Society's 15th Anniversary This meeting of the Society will hold unusual interest because it will mark the Society's 15th birthday. In addition to the customary scientific program, the four-day convention will give recognition Meeting to mark 15th anni- versary of Society. Engineer- ing pioneers to be honored. Crabtree to retire as President. Papers program reveals little of particular interest to the projectionist. to the anniversary. The Society banquet on Wednesday evening, October 7, will honor the engineering pioneers of the industry. Certificates of honorary mem- bership will be presented to Thomas Alva Edison, Frederic Eugene Ives, Louis Lumiere, Charles Francis Jenkins, and George Eastman. Invitations to the ban- quet have been issued to Eugene Lauste, Jean A. Le Roy, Thomas Armat, Donald Bell, George Melies (France) ; Oscar Messter and Max Sladanowsky (Ger- man) ; Robert Paul and W. K. L. Dick- son (England) ; Charles Friese-Greene, son of William Friese-Greene; Miss Marie Le Prince, daughter of L. A. A. Le Prince ; Edwin Porter, and D. W. Griffith. The papers program, while listing few papers of direct interest to projectionists and to those interested chiefly in re- production in the theatre, discloses the following papers which may prove of general interest: "Mechanical Advan- tages of the Optical Intermittent Pro- jector," by J. L. Spence, Akeley Camera, Inc., New York; "Report of the Stand- ards Committee," by A. C. Hardy, Chair- man; "Report of the Color Committee," by W. V. D. Kelly, Chairman; "Pro- posed Changes in the Present Standard 35 mm. Film Perforation," by A. S. Howell and J. A. Dubray, Bell & Howell Co., Chicago. Also: "Motion Pictures inf Relief," by H. E. Ives, Bell Telephone Labora- tories; "Report of the Sound Commit- tee," by H. B. Santee, Chairman; the re- ports by the various projection commit- tees— Practice, Theory, and Screens — by H. Rubin, W. B. Rayton, and S. K. Wolf, respective chairmen; "The Screen — A Projectionist's Problem," by F. M. Falge; and "Low Amperage Reflecting Arc Lamp for Portable Sound Equip- ment," by H. H. Strong, Strong Electric Co., Toledo. What is expected to be one of the most important motion picture engineering [20] papers to be delivered in recent years will be read by Dr. Herbert E. Ives. The title of Dr. Ives' paper will be "The Problems of Projecting Motion Pictures in Relief" and it is perhaps the first thoroughgoing effort, from a scientific standpoint, to outline the scientific prin- ciples involved in the projection of mo- tion pictures in relief to obtain the effect of third dimension. Due to the tre- mendous amount of work and money that has been spent in recent years to pro- duce the third-dimension effect in mo- tion pictures, it is expected that Dr. Ives' paper will be of unusual interest to the industry as a whole. Dr. Ives is director of electro-optical research at Bell Telephone Laboratories and is responsible for the coordination in television research and much of the television research has been done un- der his direction. Abstracts of Papers The following abstracts of papers to be read at the meeting were available at the time of going to press: Studio Projection and Reproduction Practice, by John 0. Acdberg, RKO Studios, Inc., Hollywood. The number of projection rooms in Hollywood studios varies between 1 and 15, depending on the production capac- ity of the studio. Projection distances average about 60 feet. In general, re- producing equipment is furnished by the company whose recording apparatus is used. During shooting and editing of a picture, the sound track and picture are on separate films, practically doub- ling the amount of equipment needed and calling for special synchronizing de- vices. Daily and weekly routine checks cov- ering frequency characteristics, power levels and screen brightness are de- scribed, as well as small projectors and reproducers used for inspecting release prints in film processing laboratories. The paper also covers special applica- tions, such as reproducers on stages (play-backs), used for furnishing music or for special work, as in split-mat pho- tography, special uses in scoring, trick work, etc. Vertical Sound Records ■ — Recent Fundamental Advances in Mechanical Records on "Wax," by H. A. Frederick, Bell Telephone Laboratories. This paper describes recent progress which has been made in laboratory studies of mechanical records of sound cut on a wax disc. Both theoretical and experimental investigations indicate that a phonograph record cut with vertical October 1931 INTERNATIONAL PROJECTIONIST 21 undulations instead of the more usual lateral undulations possesses funda- mental advantages. The principal im- provement comes from a marked increase in the volume and frequency range over which faithful reproduction may be ob- tained. A higher volume level can be recorded for the same groove spacing and speed. More playing time can be provided with a given size record and volume level since, for these conditions, both the groove spacing and speed may be reduced. Improvements in methods of processing the stampers and in the record material give a large reduction in surface noise and hence a corresponding increase in the volume range. With these improvements the frequency range which can be satisfactorily reproduced can be extended nearly an octave to 8,000 to 10,000 cycles. Other improve- ments incidental to the improvements noted above are, great improvement in the quality of reproduction obtainable directly from a soft "wax" record and a great extension in the life of the hard record. The Problem of Projecting Motion Pictures in Relief, by Herbert E. Ives, Bell Telephone Laboratories. The essential conditions for producing pictures in stereoscopic relief are two: First, separate pictures must be made from different points of view, correspond- ing to the two eyes; second, each eye of the observer must receive its appropriate view. No compromise with these funda- mental requirements appears possible. If steroscopic projection is to be achieved in such a form that a large group of observers may simultaneously see the projected picture in relief, the distribution of the appropriate views to the two eyes must be accomplished for each observer. There are just two places where the distribution may be made: the first is at the observers' eyes; the sec- ond is at the screen on which the picture is projected. If the first method is employed, two separate images must be provided on the screen, and every observer must have means for directing one image to the right eye and one to the left eye. Such means comprise special spectacles equipped with deflecting mirrors or prisms, spectacles equipped with polariz- ing prisms, spectacles equipped with glasses of complementary colors, or spec- tacles carrying sector discs operated by synchronous motors. In each case the two images upon the screen must be dif- ferentiated in the correspondingly ap- propriate manner, that is, they must be projected side by side, they must be projected with light polarized in two planes, with colored lights, ar alter- nately. These schemes have the objec- tion that a large number of observing units must be provided, which are more or less inconvenient for the users. If distribution of the image is to be made at the screen, two images are no longer sufficient. Theoretically an ex- tremely large number must be provided, a separate one for each position that can be occupied by any eye in the audi- ence, so that wherever an observer may station himself each eye will see a sep- arate image, properly differentiated in character from that received by the other eye. Still pictures exhibiting relief from whatever direction viewed (parallax panor magrams) have been produced having the property of showing relief from all angles and distances of obser- vation. These are made by photograph- ing an object from a large number of points of view through an opaque line grating, or ridged screen, and viewing the resultant picture through a similar grating. Some development of the paral- lax panoramagram method is indicated as the theoretical solution of the prob- lem of projection in relief. Several methods of utilizing the paral- lax panoramagram method are dis- cussed. It appears that from the theo- retical standpoint the problem of relief projection is entirely solvable, and ex- perimental tests of still picture projec- tion have been successfully made. Practically the solution of relief projec- tion of motion pictures will depend upon the use of apparatus involving excessive speeds of operation, great multiplicity of taking or projecting units, projection screens containing minute ridged re- flecting or refracting elements of extreme optical perfection, projection lenses of extraordinary defining power, micro- scopic accuracy of film positioning and photographic emulsions of speeds aH present unknown. Utilization of Desirable Seating Areas in Relation to the Screen Shapes and Sizes and Theatre — Floor Inclinations, by Ben Schlanger. The aim of this paper is to establish a relationship between the bodily pos- ture of the patron, the size and shape of the picture, and the architectural form of the theatre in all its details. The present type of theatre floor is compared with the reversed type described in a previous paper in order to show how the latter type of floor enables a greater number of seats to be placed within the desirable seating areas. An anlaysis is also made of the effect of the reverse floor as contributing to comfortable bodily posture. Definite angles of sight specified by the various tilts of chair backs found necessary for good posture are shown. Several forms of theatres of various seating capacities and screen sizes are described in order to show the broad application of the theories involved in reversing the pitch of the orchestra floor. Western Electric Noiseless Record- ing, by H. C. Silent, Electrical Research Products. The Western Electric method of noise- less recording with the light valve is de- scribed. The general principles are dis- cussed, the circuit diagram is explained, and the method of adjusting the device for service described. The photographic characteristics of film are considered and their application in noiseless record- ing is shown in some detail. P. A. C. JOTTINGS Regional representa- tives on technical ac- tivities appointed by James J. Finn PREPARATIONS for an active Fall and Winter season by the Projection Advisory Council are now being made. Announcement of the appointment of re- gional representatives on Council tech- nical activities has been made by James J. Finn, Chairman of the Ways and Means Committee, and is appended here- to. These appointments, made with the approval of President Thad Barrows and Executive Vice-President P. A. McGuire, will enable the Council to coordinate its activities throughout this country and in Canada and will make for direct contact with projectionists in the respective ter- ritories. The roster is not yet complete, several appointments still remaining to be made. A call for a meeting of officers and directors of the Council to be held in New York on October 16 has been issued by P. A. McGuire. At this meeting plans for the coming season will be outlined, with special attention due to be given the matter of increasing the membership of the Council. The Council still is awaiting action by the Technical Bureau of the Academy of Motion Pictures Arts and Sciences re- garding suggested changes in the Stand- ard Release Print, the specifications of which received the approval of the Tech- nical Coordination Committee of the Council several months ago. These changes are in. the main concerned with the number, position and size of the visual cue signals which appear on the S. R. P. The questionnaire circulated by the Academy through the Council disclosed general approval of the S. R. P., although many projectionists registered their preference for smaller and fewer dots. Very few requests fa- voring changing the dots from the upper to the lower corner of the frame were received. As soon as a report on these changes is received from the Academy, the Coun- cil will make every effort to see that the S. R. P. is enforced in the field. The regional representatives will play an ac- tive part in this campaign. For its part, the Academy will work through the Mo- tion Picture Producers and Distributors of America (Hays organization), in see- ing that exchanges observe the provisions of the standard, in addition, of course, to overseeing studio practice. It appears unlikely that any action will be taken on the suggestion that a penalty for non-observance of S. R. P. 22 INTERNATIONAL PROJECTIONIST October 1931 QUESTIONS & ANSWERS A department which will be a regular monthly feature and to which all pro- jectionists are invited to contribute. /Question and answer departments ^^ are valuable only to the extent to which readers cooperate in making them so. An active reader interest in this de- partment will benefit not only the in- dividual but the craft at large. Ques- tions will be answered in the order in which they are received. All questions will be numbered. Neither names nor initials will be appended to the ques- tions; but any comment relating to the answers will include the writer's name. Send in your questions now. — Editor. 1. What effect will the placing of the projection room above the center of the screen have on the shape of the picture? Ans. — This will result in what is com- monly known as a "keystone effect." 2. Is it advisable to plass glass in obser- vation ports, and if so, why? Ans. — Yes, because glass ports will prevent the emanation of sound from the projection room into the auditorium. These glass ports should be opened for inspection of the screen by the projec- tionist. 3. Would you use water on a film fire? Ans. — No. Water will not extinguish a film fire. 4. Why should both ends of the rewind- ers be in line with each other? Ans. — To prevent damage to the film, particularly to the sprocket holes. 5. What will cause film to stop or pile up at the aperture opening or in front of the light beam? Ans. — (a) Intermittent sprocket not turning; (b) a break in the fim after it passes the top sprocket; (c) take-up not functioning properly. 6. What will unequal gate springs or traps do to the film? Ans. — It will cause uneven tension. 7. // sprocket idler rollers are out of line or binding, what may happen to the film? Ans. — The film may run off the sprocket and result in serious damage to the film. 8. Why are new prints waxed, while old film is not? Ans. — On new film the emulsion is likely to adhere to the traps. On old film the emulsion is fairly well hardened. However, processing is preferable to waxing. 9. Name some causes for "rain effect" on a motion picture screen. P. A. C. Jottings specifications be invoked, both the Coun- cil and the Academy concurring in the opinion that cooperative action between all agencies concerned will net better results. The regional representatives on tech- nical activities, as announced by Mr. Finn, follow: Boston, Mass. James L. Caddigan, 355 Chapman St., Canton, Mass. New York, N. Y. Charles F. Eich- horn. Local Union 306, 125 West 45th St., New York. Los Angeles, Calif. H. E. Alford, 2828 West Boulevard, Los Angeles. Oakland, Calif. George Lancaster, Olympic Hotel, Oakland. Milwaukee, Wise. Frank M. DeLo- renzo, 4221 Oakland Ave., Milwaukee. New Orleans, La. E. L. Beaud, Local Union 293, P. 0. Box 293, New Orleans. Salt Lake City, Utah. George A. Yager, 167 N. W. Temple St., Salt Lake City. Montreal, Que., Canada. H. Delorme, 366 Mayor St., Office 22, Montreal. Portland, Oregon. James L. Forsyth, 501 Labor Temple, Portland. S'an Francisco, Calif. W. G. Woods, 230 Jones St., San Francisco. Toronto, Ont., Canada. H. N. El- liott, 27 Sherwood Ave., Toronto. Albany, N. Y. Claude Watkins, care of Strand Theatre, Albany. Oklahoma City, Okla. Berlin Parks, P. 0. Box 380, Oklahoma City. Minneapolis, Minn. Chauncey L. Greene, 2722 Harriet Ave., Minneapolis. Washington, D. C. Emil Holz, 903 Delafield Place, Washington. Detroit, Mich. Ira Waddell, 640 Park- view Ave., Detroit. St. Louis, Missouri. 0. Kleintopf, 237 Missouri Building, St. Louis. Buffalo, N. Y. Alec E. Cohen, Local Union 233, 408 Pearl St., Buffalo. Cleveland, Ohio. Victor Welman, 207 Finance Building, Cleveland. Chicago, III. P. L. Akins, 919 Cor- nelia Ave., Chicago. Vancouver, B. C, Canada. John C. Richards, P. 0. Box 345, Vancouver. Pittsburgh, Pa. Alfred L. Criswell, 3994 Beechwood Blvd., Pittsburgh. Charleston, S. C. J. H. Keener, P. O. Box 671, Charleston. Ans. — The chief cause of "rain effect" is the accumulation of dirt in scratch grooves of the emulsion. When the film is rewound, this dirt is ground into the film and results in the "rain effect" when the film is next projected. This damage usually is done in rewinding. 10. What is the cause of flicker? Ans. — A slow - running projector. However, when the standard sound pic- ture speed of 90 feet a minute is ad- hered to, there should be no difficulty with flicker. 11. What causes white streaks both up and down from letters or titles? Ans. — 'The shutter cut-off blade is too narrow. 12. What will cause film to have an up- and-down movement on the screen? Ans. — (a) A defective intermittent; (b) improper (loose), tension. 13. Hoiv would you correct "travel ghost." Ans. — By properly timing the shutter. 14. Why is a revolving shutter used on a projector? Ans. — To cut-off the light while the film is in motion. 15. Give some causes of condenser breakage. Ans. — (a) The condensor is too close to the light source ; ( b ) improper ven- tilation; (c) the holder is too tight and does not permit the usual expansion and contraction of a condenser. 16. How can the "size" of a wire be meas- ured? Ans. — With a wire gauge. 17. Can a cracked mirror be used? Ans. — Yes, but with inferior results. 18. Why do high intensity arcs have the positive carbon revolve? Ans. — To keep a round crater and thus insure even burning. 19. What is the best to use on A.C. — an economizer or rheostat, and why? Ans. — An economizer, because it is more economical. 20. For what is a rheostat used? Ans. — To reduce the voltage to the de- sired arc voltage and or to give the de- sired amperage. Send in your questions MOTOR GENERATOR REPAIRS The maintenance of electrical ma- chinery covers little points of systematic care which if followed keep the pulleys turning without much trouble. 1. Systematic oiling. ' 2. Systematic cleaning. 3. Care of d. c. commutators. 4. Care of d. c. brushes. 5. Care of d. c. starting device. 6. Care of a. c. rings. 7. Care of a. c. commutator rings. 8. Care of a. c. starting device. 9. Care of proper size of fuse. 10. General checking of schedule. ^ e Vol. 1, No. 1 EDITORIAL PAGE OCTOBER 1931 Wanted: A Projectionist Organization Formerly, projection was never given a thought other than with respect to how much it cost on the whole; but things are different to- day. This new interest in pro- jection is reflected in the bidding by executives and or- ganizations for the favor of the projectionist — they pay him pretty compliments, they make speeches about the importance of projection, and they stick an organization membership blank in his hand and "invite" him to affil- iate. And, sad to relate, some projectionists react to such advances like a cat reacts to gentle stroking. We don't want to engender any animosity by these re- marks, but we must say that projectionists give us a head- ache these days by thsir insistence upon intruding where they are not really wanted, "invitations" nowithstanding. It is all very well to say (in a speech), that we are all "one big happy family, so let's all work together." This is great stuff — in a speech. But it hardly ever works out well in practice, particularly where, as is the case with respect to the relation of projection to the rest of the in- dustry, in the very nature of things the interests of one faction do not coincide with those of another. There would not, could not, be any reason for complaint if pro- jectionists would first favor their own organizations, and then affiliate with another in addition. But projectionists "pass up" their own organizations and clamor for admit- tance to organizations in which they do not belong and are not wanted. These latter organizations may admit pro- jectionists, but in so doing they never accept them: they merely tolerate them and offensively patronize them. Where is the man who can establish, or build upon an existing nucleus, an organization that will promote the interests of the projectionist all along the line? The situ- ation demands either a Moses or a Washington, or maybe a combination of both. Such a man would supply the answer to a problem that is becoming increasingly im- portant as the days flit by. Such a man would change the status of the projectionist from that of an humble supplicant for favors to that of a respected craftsman who could speak with an authoritative voice and command proper attention for his work and for his craft. The Question of Proper Power Supply Sponsorship of all A. C. -operated sound reproducing systems by reputable engineering companies has given impetus to the demand for this type of equipment and has revived interest in the old question as to what con- stitutes the most satisfactory source of power supply. Some two years ago a hue and cry was raised against the use of storage batteries, and we were in the vanguard of that group which shouted lustily that batteries must go. As a matter of fact, we have the now somewhat doubtful honor of having been the first to suggest that storage bat- teries be replaced by (1) motor generator sets; (2) rec- tifiers, and/or (3) the substitution of a coarse exciter lamp filament for the conventional thin filament. These suggestions were couched in very positive terms: our statements admitted of no contrary opinion. Oh, well. . . The question is: Do storage batteries provide the most satisfactory source of power for sound reproducing sys- tems, and if so, why? One group supports the opinion that there is no kind of generated or induced current that will give a straight line voltage curve; batteries, this group holds, supply a constant, even flow of current far beyond the "danger line" for sound reproduction. An- other group holds that several substitutes may be utilized which are "just as good" and, furthermore, less ex- pensive and not one-half the "nuisance" that batteries are. If any unit of equipment can be replaced by some- thing "just as good" which is less expensive, by all means make the replacement. But first we should establish defi- nitely the facts which prompt the statement "just as good." As for storage batteries being a "nuisance" it should be pointed out that any substitute equipment will certain!} require some measure of attention — possibly as much or more than is now given to batteries. Regarding the mat- ter of expense, time alone will provide the answer. Statements of "just as good" usually are backed with little performance data. One's ears may easily deceive one in any comparative test of sound quality, and even the trained ear is liable to error in judging any such test. What is needed in this particular case is fact, not fancy; performance figures should tell the story. Modern science has provided the means for obtaining the answer to this problem; and we will gladly cooperate to the best of our abilty to supply this answer. Why Not Remote Volume Control? The problem of proper volume control still provokes much thought and comment among sound motion picture technicians. The Practical Projection Commit- tee reported to the Hollywood Convention of the S.M.P.E. that "the proper and best place for observance of volume is in the auditorium among the audience." The same re- port also stated that "there are now devices on the market which permit remote control. Whether the use of these devices has proven effective is not clear, but the fact re- mains that there is a general urge from the industry to in- vestigate fully the whole problem of volume control." And there the matter rests. Projectionist opposition to remote volume control is quite silly, in addition to being futile. Volume control is not now and never has been properly the concern of the projectionist. Simply because the first sound picture equipments provided for volume control by the projec- tionist from a fader on the projection room wall, with the monitor horn as an adjunct, is no reason why this unsat- isfactory arrangement should be continued. Volume con- trol from the projection room has failed completely to fill the bill. A satisfactory remote volume control is avail- able. Why not use it? We are certain that all progres- sive projectionists will welcome such equipment. [23] NEW SCREEN IMAGE TABLE SOUND-ON-FILM E. F. in. 40 ft. 50 ft. 60 ft. 70 ft. 80 ft. 90 ft. 100 ft. 110 ft. 120 ft. 130 ft. 140 ft. 150 ft. 160 ft. 170 ft. 180 ft. 190 ft. 200 ft. 2.00" 15.8 11.9 19.9 14.9 23.9 17.9 27.9 20.9 31.9 23.9 35.9 26.9 39.9 29.9 43.9 32.9 2.25" 14.1 10.6 17.7 13.3 21.3 15.9 24.8 18.6 28.3 21.2 31.9 23.9 35.5 26.6 39.0 29.2 42.6 31.9 46.1 34.6 2.50" 12.6 9.5 15.9 11.9 19.1 14.3 22.3 16.7 25.5 19.1 28.7 21.5 31.9 23.9 35.1 26.3 38.3 28.7 41.5 31.1 44.7 33.5 2.75" 11.6 8.7 14.5 10.9 17.4 13.1 20.3 15.2 23.2 17.4 26.1 19.6 29.0 21.8 31.9 23.9 34.9 26.1 37.8 28.3 40.7 30.5 43.6 32.7 46.6 34.9 3.00" 10.6 7.9 13.2 9.9 15.9 11.8 18.6 13.8 21.3 15.9 23.9 17.9 26.6 20.0 29.3 22.0 31.9 23.9 34.6 25.9 37.2 27.9 39.9 29.9 42.6 31.9 45.3 34.0 3.25" 9.8 7.3 12.3 9.2 14.7 11.0 17.1 12.8 19.6 14.7 22.1 16.0 24.5 18.4 27.0 20.3 29.5 22.1 31.9 23.9 34.4 25.8 36.8 27.6 39.3 29.5 41.7 31.3 44.2 33.1 3.50 " 9.1 6.8 11.4 8.6 13.7 10.3 15.9 11.9 18.2 13.7 20.5 15.4 22.8 17.1 25.1 18.8 27.4 20.5 29.6 22.2 31.8 23.9 34.1 25.5 36.4 27.3 38.7 29.0 41.0 30.8 43.3 32.5 45.6 34.2 3,75" 10.6 7.9 12.7 9.5 14.8 11.1 17.0 12.8 19.1 14.4 21.3 16.0 23.4 17.6 25.5 19.1 27.7 20.7 29.8 22.3 31.9 23.9 34.1 25.6 36.2 27.2 38.3 28.8 40.4 30.3 42.6 31.9 4.00" 9.9 7.4 11.9 8.9 13.9 10.4 15.9 11.9 17.9 13.4 19.9 14.9 21.9 16.4 23.9 17.9 25.9 19.4 27.9 20.9 29.9 22.4 31.9 23.9 33.9 25.4 35.9 26.9 37.9 28.4 39.9 29.9 4.25" 9.4 7.1 11.3 8.5 13.2 9.9 15.0 11.3 16.8 12.6 18.7 14.0 20.6 15.4 22.5 16.8 24.4 18.3 26.3 19.7 28.2 21.1 30.0 22.5 31.9 23.9 33.8 25.3 35.7 26.8 37.6 28.2 4.50" 10.7 8.0 12.4 9.3 14.2 10.6 16.0 12.0 17.7 13.3 19.5 14.6 21.3 15.9 23.0 17.2 24.8 18.6 26.6 19.9 28.3 21.2 30.1 22.6 31.9 23.9 33.7 25.3 35.5 26.6 4.75" 10.1 7.6 11.8 8.9 13.5 10.1 15.2 11.4 16.8 12.6 18.4 13.8 20.1 15.1 21.8 16.4 23.5 17.6 25.2 18.9 26.8 20.1 28.5 21.4 30.2 22.6 31.9 23.9 33.6 25.2 5.00" 11.2 8.4 12.8 9.6 14.4 10.8 16.0 12.0 17.6 13.2 19.2 14.4 20.8 15.6 22.3 16.8 23.9 17.9 25.5 19.1 27.1 20.3 28.7 21.5 30.4 22.8 32.0 24.0 5.25 " 10.6 7.9 12.1 9.1 13.7 10.3 15.2 11.4 16.7 12.5 18.2 13.7 19.7 14.8 21.2 15.9 22.8 17.1 24.3 18.3 25.9 19.4 27.4 20.5 28.9 21.7 30.4 22.8 5.50" 10.2 7.6 11.6 8.9 13.0 9.8 14.5 10.9 15.9 11.9 17.4 13.0 18.8 14.1 20.3 15.2 21.7 16.3 23.2 17.4 24.6 18.5 26.1 19.6 27.5 20.6 29.0 21.7 5.75" 11.0 8.3 12.4 9.3 13.8 10.3 15.2 11.4 16.6 12.4 18.0 13.5 19.4 14.5 20.8 15.6 22.2 16.6 23.6 17.7 25.0 18.7 26.4 19.8 27.7 20.8 6.00" 10.6 8.0 11.9 8.9 13.3 9.9 14.6 10.9 15.9 11.9 17.3 13.0 18.6 14.0 19.9 15.0 21.3 16.0 22.6 17.0 23.9 17.9 25.2 18.9 26.5 19.9 6.25 " 10.2 7.7 11.5 8.6 12.7 9.5 13.9 10.4 15.2 11.4 16.5 12.4 17.8 13.3 19.1 14.3 20.4 15.3 21.6 16.2 22.9 17.2 24.2 18.1 25.5 19.1 6.50" 11.0 8.3 12.3 9.2 13.5 10.1 14.7 11.0 15.9 11.9 17.1 12.8 18.3 13.7 19.6 14.7 20.8 15.6 22.0 16.5 23.3 17.5 24.5 18.4 6.75" 10.6 7.9 11.8 8.8 13.0 9.8 14.2 10.7 15.4 11.6 16.5 12.4 17.7 13.3 18.9 14.2 20.1 15.1 21.3 16.0 22.5 16.9 23.7 17.8 7.00" 10.2 7.6 11.4 8.5 12.5 9.4 13.7 10.3 14.8 11.1 15.9 11.9 17.0 12.8 18.2 13.7 19.3 14.5 20.5 . 15.4 21.6 16.2 22.8 17.1 7.50" 10.6 7.9 11.6 8.7 12.7 9.5 13.8 10.3 14.8 11.1 15.9 11.7 17.0 12.8 18.1 13.6 19.2 14.4 20.2 15.2 21.3 16.0 8.00" 10.9 8.2 11.9 8.9 12.9 9.7 13.9 10.4 14.9 11.2 15.9 11.9 16.9 12.7 17.9 13.4 18.9 14.2 19.9 14.9 8.50" 10.2 7.6 11.2 8.4 12.2 9.1 13.1 9.8 14.0 10.5 15.0 11.2 15.9 11.9 16.9 12.7 17.8 13.4 18.8 14.1 9.00" 10.6 7.9 11.5 8.5 12.4 9.2 13.2 9.9 14.1 10.6 15.0 11.3 15.9 11.9 16.8 12.6 17.7 13.3 Above table of screen images figured on basis of sound-on-film aperture — 0.800" x 0.600" [24] FIGURED ON BASIS OF APERTURE ON the preceding page is published for the first time a table show- ing the size of screen images at different distances with lenses of dif- ferent focal lengths, computed on the ture of 0.8000" x 0.600". This table was computed at the request of Inter- national Projectionist by the Scien- tific Bureau of Bausch & Lomb Optical Company, to whom this publication and basis of the sound-on-film picture aper- all motion picture technical workers are PROJECTION TABLE SHOWING SIZE OF SCREEN IMAGES DIFFERENT DISTANCES WITH LENSES OF DIFFERENT FOCAL LENGTH Size of Picture Aperture: 0.906" x 0.6795" E. F. 40 50 in. ft. I ft. 2.00' 18.0 22.6 13.5*16.9 60 70 80 90 100 110 ft. ft. ft. ft. ft. ft. 27.1 31.6 36.2 40.7 45.2 20.3 23.7 27.1 30.5 33.9 120 ft. 130 ft. 140 ft. 150 ft. 160 ft. 170 ft. 180 ft. AT 190 ft. 2.25" 16.0 12.0 20.1 15.0 24.1 18.1 28.1 21.1 32.1 24.1 36.2 27.1 40.2 30.1 44.2 33.2 L2.50" 14.4 10.8 18.0 13.5 21.7 16.3 25.3 19.0 28.9 21.7 32.5 24.4 36.2 27.1 39.8 29.9 43.4 32.6 i2.75" 13.1 9.8 16.4 12.3 19.7 14.8 23.0 17.2 26.3 19.7 29.6 22.2 32.9 24.7 36.2 27.1 39.5 30.6 42.8 33.1 46.1 35.5 ,3.00" 12.0 9.0 15.0 11.3 18.0 13.5 21.0 15.8 24.1 18.1 27.1 20.3 30.1 22.6 33.2 24.9 36.2 27.1 39.2 29.4 42.2 31.7 45.2 33.9 3.25" 11.1 8.3 13.9 10.4 16.7 12.5 19.4 14.6 22.2 16.7 25.0 18.8 27.8 20.9 30.6 22.9 33.4 25.0 36.2 27.2 39.0 29.2 41.7 31.3 44.5 33.4 .3.50" 10.3 7.7 12.9 9.7 15.5 11.6 18.0 13.5 20.6 15.0 23.2 17.4 25.8 19.4 28.4 21.3 31.0 23.2 33.5 25.1 36.0 27.0 38.7 29.0 41.3 31.0 43.9 33.0 46.5 34.9 3.75" 12.0 9.0 14.4 10.8 16.8 12.6 19.3 14.4 21.7 16.2 24.1 18.1 26.5 19.9 28.9 21.7 31.4 23.5 33.8 25.3 36.2 27.1 38.6 28.9 41.0 30.8 43.4 32.6 45.8 34.4 4.00" 11.3 8.5 13.5 10.1 15.8 11.8 18.0 13.5 20.3 15.2 22.6 16.9 24.8 18.6 27.1 20.3 29.4 22.0 31.6 23.7 33.9 25.4 36.2 27.1 38.4 28.8 40.7 30.5 43.0 32.2 4.25" 10.7 8.0 12.8 9.6 14.9 11.2 17.0 12.8 19.2 14.4 21.2 15.9 23.4 17.5 25.5 19.1 27.6 20.7 29.8 22.3 31.9 23.9 34.0 25.5 36.2 27.1 38.3 28.7 40.4 30.3 ^50" 10.1 7.6 12.1 9.1 14.1 10.6 16.1 12.1 18.1 13.6 20.1 15.0 22.1 16.6 24.1 18.1 26.1 19.6 28.1 21.1 30.1 22.6 32.1 24.1 34.1 25.6 36.2 27.1 38.2 28.6 4.75" 11.4 8.6 13.3 10.0 15.3 11.5 17.2 12.9 19.0 14.3 20.9 15.7 22.8 17.1 24.7 18.5 26.6 20.0 28.5 21.4 30.4 22.8 32.3 24.3 34.3 25.7 36.2 27.1 5.00" 10.9 8.2 12.7 9.5 14.5 10.9 16.3 12.2 18.0 13.5 19.9 14.9 21.7 16.2 23.5 17.6 25.3 19.0 27.1 20.3 28.9 21.7 30.7 23.0 32.5 24.4 34.4 25.8 5.25" 10.3 7.7 12.0 9.0 13.7 10.3 15.5 11.6 17.2 12.9 18.9 14.2 20.6 15.5 22.4 16.8 24.1 18.1 25.8 19.4 27.5 20.7 29.3 22.0 31.0 23.2 32.7 24.5 5.50" 11.5 8.6 13.1 9.8 14.7 11.1 16.4 12.3 18.0 13.5 19.7 14.8 21.3 16.0 23.0 17.2 24.6 18.5 26.3 19.7 27.9 20.9 29.6 22.2 31.2 23.4 5.75" 11.0 8.2 12.5 9.4 14.1 10.6 15.7 11.8 17.3 12.9 18.8 14.1 20.4 15.3 22.0 16.5 23.6 17.7 25.1 18.8 26.7 20.0 28.3 21.2 29.9 22.4 6.00" 10.5 7.9 12.0 9.0 13.5 10.1 15.0 11,3 16.5 12.4 18.0 13.5 19.6 14.7 21.1 15.8 22.6 16.9 24.1 18.1 25.6 19.2 27.1 20.3 28.6 21.5 6.25" 10.1 7.6 11.5 8.6 13.0 9.7 14.4 10.8 15.8 11.9 17.3 13.0 18.7 14.1 20.2 15.2 21.6 16.3 23.1 17.3 24.5 18.4 26.0 19.5 27.4 20.6 6.50" 11.1 8.3 12.5 9.4 13.9 10.4 15.3 11.4 16.6 12.5 18.0 13.5 19.4 14.6 20.8 15.6 22.2 16.7 23.6 17.7 25.0 18.8 26.4 19.8 6.75" 10.7 8.0 12.0 9.0 13.3 10.0 14.7 11.0 16.0 12.0 17.4 13.0 18.7 14.0 20.1 15.0 21.4 16.0 22.7 17.1 24.1 18.1 25.4 19.1 7.00" 10.3 7.7 11.6 8.7 12.9 9.7 14.2 10.6 15.5 11.6 16.8 12.6 18.0 13.5 19.3 14.5 20.6 15.5 21.9 16.4 23.2 17.4 24.5 18.4 7.50" 10.8 8.1 12.0 9.0 13.2 9.9 14.4 10.8 15.6 11.7 16.8 12.6 18.0 13.5 19.3 14.4 20.5 15.3 21.7 16.3 22 9 17^2 8.00" 10.1 7.6 11.3 8.4 12.4 9.3 13.5 10.1 14.6 11.0 15.8 11.8 16.9 12.7 18.0 13.5 19.2 14.4 20.3 15.2 21.4 16.1 8.50" 10.6 7.9 11.6 8.7 12.7 9.5 13.8 10.3 14.8 11.1 15.9 11.9 17.0 12.7 18.0 13.5 19.1 14.3 20.2 15.1 9.00" 10.0 7.5 11.0 8.2 12.0 9.0 13.0 9.8 14.0 10.5 15.0 11.3 16.0 12.0 17.0 12.8 18.0 13.5 19.0 14.3 The above table of screen images, figured on the basis of the silent-film aperture, will make an interesting comparison with the table which appears on the page opposite. [25] indebted for this service. First publica- tion of this table naturally is made ex- clusively in International Projec- tionist. All such tables heretofore have been computed on the basis of the silent-film, or full-width, picture aperture the di- mensions of which are 0.906" x 0.6795". Tables computed on this basis have had appended thereto a note stating that in its application to the reduced size (sound-on-film aperture), it would be necessary to substract 11 per cent from the dimensions of the screen picture as given in the table. Apart from the fact that this per- centage figure is not strictly correct (the figures being closer to 12 per cent), the necessity for such computation re- sulted in frequent, and often serious, er- ror, loss of time and annoyance in gen- eral. This new table eliminates all this trouble and enables one to note at a glance the correct figures for any size screen image at any distance and with lenses of different focal lengths. On the page following appears the table of screen images previously used and which is figured on the basis of the old standard silent-film aperture size. This table will provide an interesting comparison with the new table. International Projectionist wishes to compliment Bausch & Lomb Optical Company for the readiness with which it rendered this service to projectionists. LINE VOLTAGE REGULATOR SOUND SYSTEM NECESSITY MANY sound equipment amplifiers are designed to operate on 110 volts A. C. In many localities the volt- age varies bewteen 90 and 130 volts, de- pending upon the locality, the load upon the line, transformer equipment, time of day, and other factors beyond the control of the power company and the designer of the apparatus. Thus the actual volt- age applied to a sound amplifier may vary within wide limits, either momentar- ily, due to a sudden heavy load upon the line, or steadily, as in the case of a volt- age drop due to a long transmission line. Vacuum tubes operated below the spe- cified voltage provide poor tone quality and weak volume. High line voltage will result in distortion, and also will cause serious injury to the amplifier's compo- nent parts, such as transformers, resis- tors, and vacuum tube filaments. If the line voltage maintained a drop in volt- 26 INTERNATIONAL PROJECTIONIST October 1931 age, it might be compensated for by the use of a properly designed low-voltage transformer. Unfortunately, however, alternating current line voltages rise as frequently as they drop, making it imposible to em- ploy low-voltage transformers, since any increase above normal would seriously overload the vacuum tubes and compo- nent parts. The tapped transformer with a choice of two or more voltage ranges, adopted by some sound equipment manu- facturers, was a half-way improvement. It was a relief measure, but by no means a cure, being unable to cope with line voltage fluctuations. There are several types of voltage reg- ulators on the market, all intended for the same purpose. Some cover wide limits and others do not cover wide enough limits. Fox West Coast Theatres have adopted for use a special voltage regulator which consists of a step-up and step-down trans- former, a fixed resistance and a volt- meter. This type of voltage regulator operates on the automatic compensation principle: The voltage may be regu- lated at any time, so that a normal volt- age of 110 volts may be obtained. After the voltage regulator is once set, the se- ries resistance maintains the applied voltage at correct and uniform value ir- respective of line voltage variations, fluctuations and surges. When the line voltage is high, the re- sistance is likewise high, causing neces- sary voltage drop for safe-guarding the vacuum tube filaments and the compo- nent parts of the amplifier, such as filter condensers, resistors and power trans- formers. When the voltage is normal or sub-normal, the resistance is slight, caus- ing small voltage drop. This resistance also serves as a choke, thus reducing line noises to a minimum. Incorrect grid bias, incorrect plate voltages, incorrect input and output voltages, have been the cause for poor sound reproduction with many sound installations. Reasonable Care Will Prevent Extraneous Reproduction Noise BEFORE describing specific noises and causes, an anlaysis and classi- fication of the various types of noises may be of assistance. Insofar as the projec- tionist is concerned, noise may be classi- fied in two general groups: (1) That originating in the projection room or in the sound system, and (2) that which has its origin in other sources, such as ven- tilating systems, audience noise or street noise. The first of these groups may be further classified under three general headings: The first comprises those noises which reach the audience by di- rect transmission through the air from the projection room itself. Such noises include the noise of rotating machinery, loud conversation, high monitor horn volume and other noises incidental to the operation of the projection equipment. The second group includes noises of an intermittent character that are intro- duced into the sound system electrically, such as might be caused by loose con- tacts, defective fuses or run-down bat- teries. The third includes noises which also are introduced into the sound system electrically, but which are more or less steady, such as the "rush noise" from the photo-electric cell, hums from A. C. pickup, and noise resulting from the electrical transmission of mechanical vi- brations. Although noises from any source will prove distracting to an audience, this is especially true of mysterious noises com- ing from directions other than the screen. Noises coming from the direction of the screen are generally not so objectionable, especially if they are of such a nature that they may be interpreted as originat- ing in the action. Those noises reaching the audience through the air from the projection room can be prevented, or at least reduced to the point where they are no longer ob- jectionable. Except in an emergency, loud conver- sation between projectionists is quite un- necessary. If the projection room is not thoroughly sound proof, the projection- ists' conversation, even if not abnormally loud, will be heard by those seated in the rear of the audience. Reasonable care on the part of the projectionists will pre- vent criticism on this point. Loud operation of the monitor horn is likewise very annoying to the audience. The monitor is not intended for use in judging quality or volume of the sound in the auditorium. This is a duty which can be performed satisfactorily only by observation in the auditorium. Careful Handling In the handling of film the careful pro- jectionist can do much to reduce the noise originating in the projection room. Although enclosed motor-driven rewind machines are not usually excessively noisy, the ordinary hand-operated ma- chine can be, especially when operated at a high speed. If, however, it is oper- ated slowly enough to permit careful in- spection of the film for oil spots, worn sprocket holes, and insecure patches. there will be little possibility of objec- tionable noise. Reels which have been bent out of shape frequently strike against magazine walls, and their continued use should be avoided. The slamming of magazine and lamphouse doors and the occasional dropping of empty film cans are also sources of noise which are to be guarded against. Automatic changeover devices are sometimes noisy, as are also manual changeovers, if carelessly operated. An- other source, of occasional disturbance is the striking of the arcs in preparation for a changeover. However, the experienced projectionist will have little difficulty from this source. The noises described thus far are prac- tically all under the direct control of the projectionist, who can prevent their oc- currence or minimize their extent by the exercise of reasonable care in the opera- tion of his equipment. Due to the fact that they contain gears, drives and other rotating parts, projec- tors contribute their share in adding to the general noise originating in the room. Assuming that the equipment is properly designed and manufactured, the reduc- tion of noise from it becomes largely a question of careful maintenance. Proper lubrication is the first step in preventing^ wear and noise. Although the instruc- tions issued by the manufacturer should carefully be followed in lubrication, it is in general true that the more frequent use of less oil is more effective than its use in larger quantities at less frequent intervals would be, because of the reduc- tion of the danger of seepage from parts on to the film due to an excess at any one time. Gear Noise 1 Gears which show sign of excessive wear should be replaced, since in addi- tion to causing noise, considerable vibra- tion may be set up which may be picked up by the sound system. Universal joints and flexible couplings should be fre- quently inspected to insure that they are not binding and thus setting up increased vibration and therefore noise. Many of the larger theatres and the- atre chains make it a practice to com- pletely rebuild projector heads at least once a year. This represents good in- surance against breakdown and noisy^ operation. Careful glassing-in of the room port- holes and lookouts will go far in reduc- ing the amount of noise which reaches: the audience directly from the room. Vibratory noises originating in the room and transmitted to thfe auditorium through its walls and floor may be es- pecially difficult to overcome. However, a careful survey by a reliable acoustic consulting service will usually indicate- what steps should be taken to' reduce in- terfering noise in any cases of this kind- MOTION PICTURE SCREENS— METHODS OF SELECTION AND MAINTENANCE Francis M. Falge r77ie jollowing paper, prepared by Francis M. Falge of the Beaded Screen Corp., New York, N. Y., vias presented in the Symposium, on The- atre Practices at the Spring, 1931, Meeting of the S.M.P.E. in Hollywood. Much valuable data on motion picture screen surfaces and their care is contained herein. Comment by projectionists on certain phases of this paper is invited.} PICTURE presentation, especially since the advent of sound, is fraught with many difficulties, and the screen is by no means the least of these. The overcoming of all other dif- ficulties— the light source, the film, the lenses, etc. — may all be for naught if the last one, the screen, should interfere. But the exhibitor often little realizes the importance of the screen. His projec- tionists take care of all other equipment, but even they allow a dirty or imperfect screen to pass without comment. This not only means a loss of efficiency, but a loss at the box-office as well, because of dissatisfied patrons. When selecting a screen the following points, which will be discussed individu- ally, should be considered: <1) <2) (3) <4) (5) (6) (7) (8) (9) Adaptability to the particular theatre Reflective efficiency Sound characteristics Durability Uniformity Fireproofing Illusion of depth Adaptability to color Size of screen required teristics of the particular house, bearing in mind the fact that theatres have very dissimilar characteristics. Theatres may vary in width from 20 to 120 feet or more, and in length from 50 to 150 feet. They may have no balcony or they may have three; the angle of projection may be zero or it may be 35 degrees, and the screen may be from 10 to 30 feet from the front row of seats. Types of Screens There are three general types of screens : ' (a) Diffusive or matte (6) Reflective or metallic (c) Directive or beaded All three types of screens are made with openings to permit the passage of sound. Fortunately, screen characteristics are so definite that consideration of the vital principles of each of these types should permit a ready decision as to the screen best suited to a particular house. Practice seems to bear out the fact that a matte screen which radiates equally in all directions appears less brililant the farther away the observer is from it. This may be due to the loss of light through the atmosphere, a smaller in- cluded angle of light, and the interfer- ence of light sources in the house. These factors in general tend to make the screen too brilliant for those in the front rows of seats, and not sufficiently brilliant for those in the rear seats. When selecting a screen, consideration should be given to these points. (a) The Diffusive Screen. — Diffusive screens are made of cellulose coated ma- terials ; rubberized fabrics ; closely woven treated materials; coarsely woven mate- rials with or without metallic fibers; woven materials with irregular glass par- ticles; and coated metals. The distribu- tion of light from a typical diffusive screen is shown in Fig. 1. The curve in- cluding the largest area, indicating the largest reflection values, is, in general, the best. The advantages of diffusive screens may be listed as follows: (1) They redirect a large percentage of light — i.e., they are very efficient. (2) They are good for color picture projec- tion— i.e., they are not color-selec- tive (3) They redirect light through wide angles, giving satisfactory projection for wide theatres or for theatres with steep projection angles There are many kinds of screens, but all come within three general classifica- tions. There is no screen made today which is an average type best suited to all' houses. For that reason, screens should be selected which fit the charac- Fig, 1 — Character- istics of diffusive screens Fig. 2 — Showing re- lations between the- atre width and projection angle so 60 TO 80, 90 WIDTH ofhouse:(feet) .[27] 28 INTERNATIONAL PROJECTIONIST October 1931 80 60 40 20 0 20 40 HORIZONTAL ANGLE WITH NORMAL 80 Fig. 3 — Brightness characteristics of various screens DiSTANCt TROM ScRCCH TO RcAR 5 EATS ~ t Fc CT J TO DO 90 100 110 IZO 130 I40 ISO 160 I -T U5E Uppc« Scale -- Correct Picture Size For Farthest Scats Use Lower Scale Correct Picture Size For Nearest Scats Note: Tor best results front seats should be adjusted toconformto rear seat she li m itations _L J I f I. _U 2 4 6 a 10 12 14 16 Ifi 20 22 24 20 28 30 32 34 36 38 Distance from Screen to Frpnt Seats (Feet) Fig. 4 — Curves for determining proper size of picture (b) The Reflective Screen. — Reflec- tive screens are made of aluminum and other polished and coated materials, and have varying degrees of diffusiveness. Their advantages may be listed as fol- lows: (1) They build up the intensity of the re- flected light so that under certain conditions they add to the apparent brilliancy as viewed from the rear seats (2) Their use results in economies in pro- projection houses which have large ratios of length to breadth The disadvantages of reflective screens are: (1) They are not desirable where the angles of projection are greater than 10 de- grees (2) They can be used in relatively few houses (3) They are not satisfactory for the pro- jection of colored pictures — i.e., they are color-selective. We may conclude, therefore, that re- flective screens are useful for few houses because of prevalent conditions and their limited reflection angles. Also, they are not good for color picture projection. (c) The Directive Screen. — Directive screens are diffusing screens on which are imbedded glass globules; they are also called "beaded screens." Their ad- vantages may be listed as follows: (1) They build up the intensity of the re- flected light so that a more brilliant picture can be seen from the rear seats (2) They redirect the light so that to spec- tators in the balcony the picture ap- pears as good as to those on the main floor (3) They redirect the light in such a man- ner as to result in decided econ- omies (4) They assist in the illusion of the third dimension (5) They can be satisfactorily maintained, and retain much of their original brilliancy (6) They reduce the glare seen from seats near the screen (7) Because of their apparent brightness, they add life and brilliancy to color pictures The disadvantages of directive screens are: (1) They are not desirable for theatres hav- ing projection angles greater than 20 degrees because of their directive nature (2) They are not desirable for wide houses In conclusion it may be stated that beaded screens, while very efficient, re- direct the light and provide a more satis- factory picture in houses of medium width having projection angles up to 20 degrees. Because of the great brilliancy and the decided contrasts, the tone quali- ties of the picture are enhanced, espe- cially in the case of color pictures. Beaded screens also redirect the light so as to provide those in the balcony with as good a picture as those on the main floor. Selection of a Screen Invariably, it is a mistake to select a screen for one theatre by viewing a screen in another theatre. The many whims of projection equipment all con- tribute to mislead the observer, and in the final analysis, the characteristics of the houses will probably differ so much that a proper choice is impossible. Then, too, our eyes are not trained to evaluate the brightnesses in cases such as these. Consideration of the foregoing analy- sis, the charts of Fig. 2 and Fig. 3, and the physical characteristics of the par- ticular theatre for which the screen is intended, will permit the selection of the best type. The other factors which follow will assist in making the proper selection of the best screen of that type. The total reflection of light from a screen, apart from measurements of its reflection characteristics in various di- rections, is very important, as it is on this factor that one phase of eSiciency de- pends. Of two similar types of screen, the one with the highest over-all efficiency is likely to prove best. This is illustrated in Fig. 1, where the largest curve indi- cates the most efficient screen. The re- flective efficiency of the screen is closely linked with the reffective efficiency of the coating material, titanium pigment being an excellent white reflective pig- ment. Aluminum, on the contrary, has relatively low efficiency, and consequently metallic screens are usually of low ef- ficiency. Light tests of screens should include measurements of reflective ef- ficiency. In practically all cases, horns are now placed behind the screen, the sound pass- ing through the screen via interstices in woven cloth or perforations in opaque material. When this method was first used, the matter of sound transmission was considered all-important, compared with other considerations, and the picture suffered decidedly. It was later found that a relatively small percentage of open space — as low as 4 per cent — could be used, the present compromise being about 8 per cent. An arbitrary figure of ap- proximately 3 decibels loss was decided as allowable by Electrical Research Products, Inc. RCA Photophone, Inc., and other manufacturers have allowed somewhat greater tolerances. Consider- ing the great losses in other parts of the system, such as in the horns, the allow- able loss for screens would seem rather severe, but fortunately, a fairly good pic- ture can be produced on a screen meeting this requirement. Also because of vary- ing methods of test, it does not seem pos- sible to make two tests that check, so' that, under the present system, the value of these tests is questionable. Screen Durability Under this subject the following fac- tors must be considered: (a) The ability of the screen to withstand abuse, during handling and hanging: (b) Its strength at the seams (c) The effect of dirt collection (d) The effect of washing and reprocessing The abuse that the average sound October 1931 INTERNATIONAL PROJECTIONIST 29 Description Picture Screen Inside of Frame Standard 9'0 by 12' 9'6 by 12'6 10'6 by 13'6 Substandard 10'6 " 14' ll'O " 14'6 12'0 " 15'6 Standard 12'0 " 16' 12'6 " 16'6 13'6 " 17'6 Stibstandard 13'6 " 18' 14'0 " 18'6 IS'O " 19'6 Standard 15'0 " 20' 15'6 " 20'6 16'6 " 21'6 Substandard 16'6 " 22' 17'0 " 22'6 18'0 " 23'6 Standard 18'0 " 24' 18'6 " 24'6 19'6 " 25'6 Magnoscope 24'0 " 36' 25'0 " 37'0 26'0 " 38'0 a 26'0 " 40' 27'0 " 41'0 28'0 " 42'0 " 28'0 " 40' 29'0 " 41'0 30'0 " 42'0 Table A screen receives is astonishing. When hanging the screen, often too little care is taken, and there is always the possibil- ity of tearing or damaging the surface. Ruggedness or material is a factor to consider in selecting a screen, but any screen is likely to suffer because of abuse. Furthermore, ruggedness seems to play no part in its life, as other factors, such as the collecting of dirt and method of maintaining the screen, are more im- portant. The seams should be as strong as possible, but no seams will withstand considerable abuse. Uniformity The accumulation of dirt, the washing of the screen, and methods of reprocess- ing it are the factors which determine the life of a sound screen. If properly main- tained, screens may have an effective life of one and one-half to two years. The average effective life of a sound screen is one year; screens kept in service longer than this handicap the exhibitor to a considerable extent unless they are prop- erly and regularly serviced. Two factors must be considered under this heading: (a) the uniformity when new, and (b) the uniformity after being used a while and after cleaning or re- processing. The slightest imperfection in weave or variations in depth of coating may result in a non-uniform surface; this may hap- pen even when the greatest of care is taken. Panels must therefore be care- fully matched and inspected to see that they are of the same color and are free from imperfections. The processing must be so uniform and exact that sur- face conditions and time will not cause a lack of uniformity. All screens in use today become yellow with age to a cer- tain extent. If the yellow is uniform, it is not likely to be objectionable. Im- proper cleaning or reprocessing may in- troduce streaks and imperfections, and may considerably increase the tendency to become yellow. At the time of pro- cessing, the screens may have a uniform appearance, but when dry the imperfec- tions will gradually appear. Be sure that this is given consideration before allow- ing a screen to be resurfaced. Some time ago, because screens were made of highly inflammable cellulose materials, considerable agitation was raised in certain quarters concerning fireproof screens. By adding certain in- gredients and eliminating others, the various screen coatings were made fire- resistant. Fabrics are best made fireproof by impregnating them. A slow-burning material, however, when stretched verti- cally, does not constitute a fire hazard; but if a fire-resistant material is selected, there need be no fear of objection by local inspectors. Successful fireproofing of a screen im- mediately after it is made or while in place in the theatre has not yet been accomplished. Screens are such a small item of the stage equipment, and so much less inflammable, that there need be no fear of fire from them. In gen- eral, it is best fo^ each exhibitor to choose his screen according to his local ordinances. The illusion of depth is a very debat- able matter; it seems to be connected with the method of photography used. By obtaining the proper contrast between highlights and shadows, an illusion of depth seems to be created. Beaded screens have been selected for wide film projection in a number of instances be- cause of this feature. Adaptability to Color Color brilliance and purity is, to a considerable extent, dependent on the light intensity. For this reason a bright screen will, in general, if of neutral char- acter, give better results for all colors than a screen which is less bright. For colors, screens should have no tint other than that which is required to neutralize the color of the light source, assuming that it has a definite color. A metallic screen is usually quite color-selective, whereas beaded and white diffusive screens are neutral in character. Closely paralleling this problem is that of ob- taining the correct tone quality of the reflected picture. Attempts to tint the screens in order to impart a certain tone quality to the picture are likely to be undesirable when colored pictures are projected, and because of the different qualities of the various arc sources them- selves. Size of Screen The problem of choosing the proper size of screen is an important one. A new installation is the simplest to plan, but when a theatre needs a new screen, the problem should be carefully consid- ered. The problem is of sufficient im- portance to warrant the replacing of the objective lens if a different size of screen seems desirable. Standard Sizes. — A system of standard screen sizes is highly desirable, and will result in economies and other advantages for both the exhibitor and the manufac- turer. Less wastage results, errors in ordering are made less frequently, ship- ping is expedited, cleaning is facilitated, and costs and prices are consequently reduced. The Projection Screens Com- mittee of the Society of Motion Picture Engineers is now developing recommen- dations for standard sizes. Information based on standards adopted individually by large circuits and manufacturers gives the list of sizes shown in Table A. Wherever possible a standard size should be substituted for a non-standard. When ordering screens, the three dimen- sions should be given; prices are based on picture sizes. House Conditions Theatres are planned with definite lines of sight, and care must be taken to keep the screen in the line of vision, espe- cially when using a screen modifier. Older theatres generally used a line of sight which provided a clear view of 16 feet from the stage floor at a point 4 feet back of the curtain line, which therefore often limited the size of the screen to 15 by 20 feet. Newer theatres often allow for a considerably greater height. The distance from the front row of seats to the screen is one of the deter- mining factors for the size of the screen. The larger the picture, the worse will the imperfections, such as graininess in the film, appear. These imperfections are very noticeable and objectionable to {Continued on page 39) Light Source Screen Throw Picture Mazda Diffusive 100 ft. 12 X 16 " Beaded 100 " 15 " 20 Low Intensity Diffusive 125 " 15 " 20 Low Intensity " 175 " 12 " 16 it a Beaded 125 " 18 " 24 a a (( 175 " 18 " 24 Table B 30 INTERNATIONAL PROJECTIONIST October 1931 TELEVISION NEWS NOTES Prospects for Television in the Theatre THE projectionist is primarily con- cerned with television from the stand- point of how soon, and in what form, it will enter the motion picture theatre. To determine the extent to which television will affect the motion picture houses, this department completed an exhaustive sur- vey of moving picture producers and ex- hibitors, as well as other organizations directly interested in television as a pos- sible box office attraction. The results of the survey revealed a general opinion that television will not be utilized, to a widespread extent, in motion picture theatres. If television does come into the movie houses, it will be from three to five years after it be- comes general in the home. Television most practical possibility, insofar as the cinema is concerned, is best expressed by the spokesman for a large television company, who says: "It is our belief that in the near future a great number of theatres will subscribe to a wire service for news television. These pictures will be picked up at the ring side, at the ball field, at the scene of important events, and so on. The pic- tures will be flashed over a group of tele- phone wires to various subscribing the- atres. In this way it will be possible for audiences to follow news events at the very time they are taking place. This is in contrast to the usual news reels which cannot be made available much under twelve hours from the time they are made." Television as a Good Investment Prospect SOME of the financial interests are suggesting television as an attractive investment possibility. Between 25,000 and 30,000 sets are said to be in daily use in this country. The potential market for television sets has been estimated at 1,000,000 by 1933. By the end of the next decade, statisti- cians say, more than 11,000,000 television receivers will be in domestic use. One financial forecasting service reports that television stocks are moving opposite the downward trend and predicts that when the general market begins to show acti- vity, television shares will move rapidly to the front. DeForest Direct Pick-Vp Television Camera THE accompanying illustration shows the new direct pick-up television camera designed and built by the De- New De Forest direct pick-up camera for television work Forest Radio Company. The light is re- flected from the performer through the lens and the 60-hole scanning disc, which is encased in the circular housing, to the photo-electric cells, which are in the box on the top of the camera. The image is monitored through the shadow box on the side of the photo-cell case, the operator seeing the image on a Neon lamp from which two wires lead. Thus the monitor sees the image in the same form as does the television audience. The camera is very flexible, may be moved about, raised, tilted and turned horizontally, and, when mounted on a truck, be used for outdoor televising. The direct pick-up camera is claimed to be an important forward step that will overcome difficulties heretofore attached to televising because of the lack of light. The idea of the direct pick-up camera is not new but is an elaboration of former attempts, chiefly to the extent of develop- ing a more sensitive photoelectric cell and the more practical use of the screen- grid high-gain amplifying tubes. The Major Problem in Television Work ASIDE from the numerous improve- ments necessary in sending and re- ceiving sets, television's broadcast prob- lem at present is similar to that which has confronted radio all of these years: — there must be an adjustment of wave lengths to allow for more distance and fewer interferences. Short wave transmission, for both radio and television, is considered by experts to be the solution to the problem. This LIST OF TELEVISION STATIONS Call Letters W2XCR W3XK W2XCD W2XBU W9XA0 W2XAP Location Owner .New York, N. Y Jenkins Television Corp. .Wheaton, Mr Jenkins Laboratories . Passaic, N.J DeForest Radio Corp. .Beacon, N. Y Harold E. Smith . Chicago, 111 Western Television Corp. . Portable Jenkins Television Corp. W3XAD Camden, N. J RCA Victor Co. W2XBS New York, N. Y National Broadcasting Co. W2XCW Schenectady, N. Y General Electric Co. W8XAV Pittsburgh, Pa Westinghouse Electric Co. W2XR Long Island, N. Y Radio Pictures, Inc. W9XAP Chicago, 111 Chicago Daily News W3XAK Bound Brook, N. J National Broadcasting Co. W2XAB New York, N. Y Columbia Broadcasting System W9XAA Chicago, 111 Chicago Federation of Labor W9XG West Layf ayette, Ind Purdue University W2XB0 Long Island City, N. Y United Research Corp. WIXAV Boston, Mass Shortwave and Television Lab. W9XR Downer's Grove, 111 Great Lakes Broadcasting Co. W6XK Los Angeles, Cal Don Lee, Inc. W9XD Milwaukee, Wis The Milwaukee Journal W2XB2 New York, N. Y National Broadcasting Co. Note: W2XR (Radio Pictures, Inc.) ; W3XAD (RCA Victor Co.) ; and WIXAV (Short Wave and Television Lab.), each televise on two bands. October 1931 INTERNATIONAL PROJECTIONIST 31 form of broadcasting will greatly ameli- orate objectionable interferences and in- crease the broadcasting range. At the same time, short wave sending and re- ceiving will make it possible to use one set for both sight and sound programs, instead of a set for each purpose, as is now necessary. Radio Corporation s Plans for Television Theatre ALTHOUGH Radio Corporation and its affiliated companies, of which RKO is a unit, are making few public announcements as to their progress with, and plans for, television, specifications for Radio City provide for the installa- tion of television equipment in their 3,500-seat motion picture theatre. It was in the RKO Proctor Theatre in Schenectady that on May 22 of last year, television was seen for the first time as part of a regular performance in a mo- tion picture theatre. World^s Highest Structure As Aid to Television THE National Broadcasting Company has installed television equipment for experimental purposes on the eighty-fifth floor of the Empire State Building, the world's tallest structure. The television studios and laboratories will occupy the east half of the eighty-fifth floor, approxi- mately one thousand feet above the street, and it is believed that operation of ap- paratus at this height above the city will be helpful in surmounting the difficulties which have beset television transmission in the past. A television antenna will be at the top of the Empire State mooring mast, one thousand two hundred and fifty feet above the street level. The new television studios and labora- tory are one floor below the Empire State observatory, the highest usuable space of the building. The engineers working there will have the distinction of being the highest technical workers anywhere in the world, their quarters being even loftier than the summit of the Eiffel Tower in Paris, the second tallest struc- ture in the world. Who Will Pay the Television Bill? WHO will pay the bill incident to putting television before the public? In expressing his opinion on the subject in "Radio in Advertising" (Harper and Brothers), Orrin E. Dunlap, Jr., Radio Editor of the New York Times, asserts that the burden will fall on the shoulders of the big advertisers. "There is no evidence," according to Mr. Dunlap, "that advertisers will shrink from the television performance. They are preparing to grasp it as they have radio. "Television will permit demonstrations, and the audience will not have to imagine what a product looks like or how : it operates," says Mr. Dunlap in his book. "A new model automobile revolving on a turntable in front of a televisor will en- able it to be introduced to the entire na- tion within a few stconds. . . . Great will be the power of television in advertising if for no other reason that the fact that one picture is worth more than 1.000 words! "Showmen and experts in color effects will be in demand. The radio dramas and concerts in many instances will be broadcast from films prepared in studios in much the same way that talkies are made. There will be news events flashed by radio cameras on the scene of action, whether it be a Presidential inauguration or a prize fight." Survey Answers Problem of Replacement Variations THERE has always been considerable speculation on the part of theatre owners and equipment manufacturers re- garding the reason for the great varia- tion in the number of replacements of parts for sound reproducing equipment. Even among theatres using the same type equipment and running the same number of hours the parts replacement figures vary widely — so much so, that one lead- ing manufacturer of sound reproducing equipment decided upon a survey to es- tablish definitely the reason for this seemingly mysterious circumstance. The survey provided a simple answer to the problem. . . . But to go on with the story. Twenty theatres, representing the vari- ous type of sound systems and providing a cross-section of the exhibiiton field, were selected for the survey work. A preliminary investigation was carried out and it was found that the theatres which had the least replacements were con- trolled by exhibitors who had no com- plaints to make and always got on ex- ceptionally well with the service engi- neers as well as with the trade in general. PETER J. BRADY WHILE flying to Detroit, Mich., where he was to address the Amer- can Legion Convention as a representa- tive of the American Federation of La- bor, Peter J. Brady, President of the Federation Bank and Trust Company of New York, was instantly killed when the plane in which he was a passenger crashed through a house on the outskirts of New York City. Mr. Brady was asso- ciated with the Photo-Engravers' Union and for a number of years was President of the New York Allied Printing Trades Council. In 1923 he organized the Fed- eration Bank and Trust Company in the interests of the workingman, which insti- tution has prospered and branched out under his capable leadership. The passing of Mr. Brady is keenly felt by officials of the I.A.T.S.E. with whom an intimate friendship had been formed in the business dealings transpiring be- tween the Alliance and the Federation Bank and Trust Company. Although this did not immediately an- swer the question, it occasioned a study of the personnel and management. Nothing was learned from the theatre itself. Although the physical character- istics of the auditorium could affect the quality of reproduction, they had no in- fluence on the actual running of the equipment itself. The study of the projection room and apparatus therein marked the first step toward the solution of the question. It was found that the theatre with few re- placemens had an immaculate projection room, and the apparatus was invariably spotless. Every little detail was care- fully looked after, even to cleaning all carbon dust from inside the lamp house. The generator room was well kept and there was no dust on or about the gen- erator itself. Everything was well pol- ished and properly lubricated, with the superfluous oil wiped off. A check-up of this type of theatre showed that every detail was carefully watched so that no slip might spoil an otherwise perfect per- formance. The theatres with heavy replacements costs were not so pleasant a study. The apparatus was usually found clean on the surface, but the details had been overlooked. Minor adjustments were far from perfect, and the small corners were usually full of dust and the lamphouses full of carbon dust and small unburnt ends. The inside of the projectors were anything but free from grease and dirt. The surveyors were then satisfied as to the reason for variation in the number of replacements, but continued to study further to ascertain if possible why one group of projectionists should take more interest in their work than .another. This finally reflected to the manage- ments. It was found in practically every case that the condition in the projection room varied directly with the policy of the management. The theatre with few replacements and spotless projection room was always well-managed and well- patronized. The theatres lacking good management also lacked tidiness, good business and orsanization. 32 INTERNATIONAL PROJECTIONIST October 1931 NEWS FROM THE SCIENCE WORLD A NEW "PERPETUAL MOTION" DYNAMO SHOWN IN GERMANY ANEW electric dynamo which either is a fake or is the most revolution- ary electric discovery of a generation is attracting attention in Germany. Prob- ably it is a fake, like the famous Keely motor and hundreds of others, for it ap- parently produces more power than is supplied to it, which amounts to per- petual motion and is contrary to all ac- cepted theories of power and energy. Invented by Herr Paul Hoffmann, of Steglitz, the new dynamo has been tested, it is claimed by the inventor, by engineers of the larger German electrical companies, by university professors, and by engineers in Sweden and Denmark. All agree, the claim is, that the power generated is 120 to 125 per cent of the power that is put in — which means, in engineering terms, an efficiency of 120 to 125 per cent. One hundred per cent efficiency, on the other hand, is regarded as the limit of perfection. Actual dyna- mos always have smaller efficiencies, ranging from 75 to 90 per cent. The performance of the new machine is not ascribed by its inventor to actual perpetual motion; everyone knows better nowadays than to deny the iirmly estab- lished scientific principle that this is im- possible. Herr Hoffmann suggests, on the other hand, that his device taps some source of energy hitherto unknown. En- gineering skeptics probably will wait for someone to discover the actual source of power, fed secretly into the machine. NOW— PATENTS ON PLANTS A new Federal law has been passed to provide for patents on plants; the first protection of this sort having been granted in August to cover a new type of ever-blooming rose. For the most part, the possibility of patent rights be- ing granted to a plant grower depends upon his producing an original plant by a sexual method, "that is, by grafting, budding, cutting, layering or division." The same 17-year period of protection applying to mechanical devices also ap- plies to patents on plants. The decision as to whether or not a plant is patentable is determined in the routine manner by the Patent Office, in conjunction with the Department of Agriculture, by means of written ap- plications and specifications, drawings and samples. NOVEL CURE FOR HAYFEVER Sunburning the inside of one's nose to cure hayfever is a medical procedure introduced recently in Austria by Dr. A. J. Cemach, of the Mariahilfer Hospital. Tilting the patient's nose up to the sun is scarcley practicabe, Dr. Cemach agrees, nor are the usual types of ar- tificial, ultraviolet-ray lamps suitable for use inside the delicate tissues of the -nose. What has proved to be practicable is a thin rod of fused quartz or rock crystal, into which powerful ultra-violet rays from a mercury lamp are introduced at one end and come out at the other. Workers with such quartz rods already have found that rays thus fed into one end will stay inside until they reach the other end, like water in a pipe. In Dr. Cemach's method, the end of the quartz rod from which the rays emerge is introduced into the patient's nostril and pushed back gently to the extreme back part of the nose. The ul- traviolet rays then are started and the quartz rod is drawn out slowly, the emerging rays bathing the whole inside of the nose as this is done. Powerful beams of rays are used, so that it is pos- sible to give the entire inside of the nose a mild sunburn in less than a quarter of an hour. PLAN NEW TYPE AIRPLANE FOR STRATOSPHERE ANEW type of airplane, constructed for flights in the stratosphere of an altitude of more than 30,000 feet has been built for the French Government according to plans suggested by Profes- sor Auguste Picaard, tbe Belgian scien- tist who recently made a balloon trip in the stratosphere in the interests of science. The plane has many novel fea- tures, including tanks which supply air to the hermetically-sealed cabin; a de- vice which maintains the proper fuel supply for the engine and an arrange- ment which prevents the fuel from freez- ing at high altitudes. The sponsors of the Picaard plane predict that it is capable of developing a speed of 465 miles an hour in the stratosphere, making the crossing of the Atlantic Ocean in ten hours a possibility. CHICAGO TELEPHOTO CENTER Chicago, on account of its central loca- tion, has been selected by the American Telephone and Telegraph Company as a central location for its system of dis- tribution of photographs by telephone. This does not mean that photographs being sent from one section of the coun- try to another are relayed through Chi- cago, but rather that the management of the system centers in Chicago and pho- tographs being sent from one point to another are still sent directly by merely plugging in the connection at Chicago with the point to be reached. More telephotographs are received in the Chi- cago office than any other city, although New York City originates the greatest amount of telephoto business in the country. SOMETHING NEW IN MEDICINE The recent important discovery at Cornell University of anti urease, the first antienzyme, has opened an important field of medical research, developments in which will be watched with intense in- terest by the medical profession and the public in general. Experiments on lower animals have shown that "the newly discovered prep- aration will nieutralize the action of enzymes, which are substances secreted by the body. The presence of enzymes in the system serves to maintain the equilibrium which has so direct a bear- ing upon normal development and, even, existence. Enzymes, for example, set up a balance which limits the size of the heart and other parts of the body to reasonable proportions. Enzymes also aid digestion and, in general, keep the body in action as an evenly developed and well balanced machine. PROVE OPEN WIRE 'PHONE FASTER THAN CABLE Experience has shown that voice waves travel much more slowly over wire circuits which are enclosed in cables than they do over those strung along poles in the open. The velocity of a voice wave over cable lines is about 30,000 kilometers per second on long distance lines, as compared to nearly 300,000 kilometers per second on open wire cir- cuits. One of the results of the slower trans- mission in cables in an echo effect which, if delayed sufficiently over a long circuit, would result in the speaker hearing- an echo of his own voice. This is prevented, or largely eliminated, by a device known as an "echo suppressor," by means of which the transmission of voice waves in one direction interrupts the path over which the echo currents are transmitted in the opposite direction. MAKE X-RAY SOUND FILM OF SINGER'S THROAT The Montag Morgen, a Berlin paper, has published a description of interest- ing experiments that were recently made with X-rays in the recording of sound films. At the State High School for Mu- sic, X-ray sound films are being made of singers. These films show the larynx, the vocal cords, and the lungs of a per- son singing, and, in addition to the ac- tual song, they also reproduce the heart and lung sounds of the singer. This combination of anatomy and music will make it possible to determine what phy- siological factors are necessary to pro- duce good singing. This possibility, which is due to the initiative of Profes- (Continued on page 38) October 1931 INTERNATIONAL PROJECTIONIST 33 COPPER OXIDE RECTIFIER INTRODUCED BY G. E. THE first copper-oxide rectifier to be introduced for the motion picture field, built to improve the growing use -of full-vision screens, wider films and ■colored motion pictures has been an- nounced by the General Electric Com- pany. The rapid strides made in the motion picture industry have required jadical changes in theatre equipment. The so-called "low-intensity" arcs in- stalled in most motion picture theatres are not entirely suitable for the present ■colored projection and greater screen areas. As a result, a rectifier of high intensity and capable of meeting these requirements was needed. One of the outstanding features of the new rectifier is that it may be used either for a high-intensity projector or for one or two low-intensity arcs. Used with a liigh-intensity projector, it supplies 60 to 70 amperes of arc current. Operated with one or two low-intensity arcs, each of the two sections supplies 30 to 35 am- peres. The new rectifier makes use of the copper-oxide disc principal of rectifica- G. E. Copper-Oxide Rectifier tion, which gives it durability, long life and freedom from maintenance expense. A system of forced ventilation, using radiating fins and two small electric blowers, forces a steady stream of cool air over the copper-oxide elements and maintains a temperature within ten de- grees of the surrounding air tempera- ture. Not until such a cooling system was perfected was it possible to develop a successful high-output rectifier. No objectionable noise is made by the xectifier, which enables it to be placed in the projection room. Installation and operation of the unit are simple. One switch starts or stops the rectifier in- stantly, without the usual "starting" or "warming up" period. RCA PORTABLE REPRODUCER SETS HIGH STANDARD RCA Photophone, Inc., announces the production of an entirely new port- able sound reproducing unit and has be- gun its manufacture on a large scale. NOTES from the SUPPLY FIELD The entire unit comprises a projec- tion machine, an ampifier, a loudspeaker and a carry-case for film and these havei an aggregate weight of slightly more than 200 pounds. The projection ma- chine is 19" high, 19" wide and its breadth is 10". The amplifier, which is built in a carry-case having a removable cover, is 26" long, 8%" high and 11" in breadth. The loudspeaker, which is of the flat baffle type, is contained in a carry-case, the dimensions of which are 81/2 X 19 X 14". Standard 35 mm. film is used and ade- quate sound reproduction is obtainable in a room or hall having a content of 75,000 cubic feet when using the 8-inch directional baffle. A 6-inch dynamic cone speaker is supplied when the cubic content does not exceed 12,000 feet. A picture about 8 x 10 feet in dimensions is obtained upon the screen from a throw of 75 feet. The equipment is AC-oper- ated from an outlet of 105 to 125 volts, either 50- or 60 cycle, single-phase power source. The total power required is approximately 12 amperes at 100 volts. Connections between the various units are made by means of suitable cables fitted with necessary plugs and recep- tacles. For a complete set-up using one projector only four cables are required. r J One is for the power supply to the pro- jection machine; one for the power sup- ply to the amplifier which may be plugged into a receptacle in the projec- tor; one to connect the signal circuit of the projector to the amplifier, and one from the amplifier to the loudspeaker. The projector is designed to accom- modate a one thousand foot standard reel, a Standard Series I theatre projec- tion lens with limits of focal lengths of 3%" to 8"; a 1,000-watt, 110-volt, pre- focused base projection lamp; a 110- volt, 7%-ampere exciter lamp, and a UX-868 photo-electric cell. KNOWLES REAR SHUTTER FOR POWERS PROJECTORS THE Knowles Rear Shutter Company of Los Angeles is now marketing a rear shutter for Powers projectors. This device modernizes the Powers projector to where it is no longer necessary to discard the Powers now in use for a heavier and more expensive make of pro- u0tt^ § '"^7 .. .c't'fKBKM RCA Portable Projector Knowles Rear Shutter jector because of the excessive heat gen- erated by the high-intensity arc. The Knowles Company claims that its device affords nearly 78 per cent cooling at the aperture, an almost complete ab- sence of film buckling, and a light in- crease of from 20- to 35 per cent at the screen. A smooth and novel framing device replaces the old jerky form of framing bar that invariably overshot the mark. A quick means of setting the shutter while running is also had with a new type of collapsible glare shield. This device is built as an integral part of the projector head mechanism and will last as long as the projector it- self. It is said to sharpen the focus to a remarkable degree. MG SETS FOR REPLACING STORAGE BATTERIES MOTOR-GENERATORS for replac- ing storage batteries in theatres have been developed by the Electric Specialty Company. These machines supply low voltage D.C. for the fields of loudspeakers and for the exciter lamps 34 INTERNATIONAL PROJECTIONIST October 1931 Macy Exponential Horn of the sound equipment. They are very carefully designed so that they do not cause any objectionabe background hum in the loudspeakers. A simple filter sys- tem is used when they supply power to th exciter lamps; but filters are not used with the horn fields. The machines are furnished complete with filters, when re- quired, and they may be readily con- nected in place of the storage batteries. These machines are of exceptionally rugged construction and are mechanical- ly designed for the least possible amount of attention and maintenance expense. Wool-packed sleeve beajings, which re- quire no attention except very infre- quent lubrication and which run very quietly are used. The machines are semi-enclosed, all live parts and rotating members being completely protected. Terminal boxes are provided for conduit connection. These motor-generators provide a re- liable source of power and, according to Electric Specialty, are more economical in the long run than other forms of power supply appartus. BURGESS BATTERY CO. HAS NEW LIGHT RELAY COMPLETE, ready-to-use light relay and light source units of extreme simplicity, ruggedness and reliability, are announced at this time by the Radio- visor Division of the Burgess Battery Co. The units are designed around the novel Burgess Radiovisor Bridge or light-sen- sitive cell, developed in England and recently made available in this country. The Burgess light relay units are available in both A.C. and D.C. models for use on usual power supplies. The units are in the form of an aluminum housing with window, containing a cir- cular platform on which the bridge, tubes and other components are mounted. The A.C. unit comprises bridge, two 427-type tubes serving as amplifier and rectifier respectively, power transformer, filter condenser, re- sistors, by-pass condensers and power relay. The D.C. unit comprises bridge, one 427-type tube serving as amplifier. voltage reducing and other resistors, by- pass condenser and power relay. The unit housing is held by a wall bracket ring, permitting of necessary adjust- ments to line up the window with the actuating light source. When provided with the Burgess Vacuum Contact, the light relay can control a circuit han- dling up to 1,320 watts. Requiring no other installation than wall or other mounting, and connecting with the usual electric outlet and the circuit to be controlled, the Burgess units are available for one end of light-control applications. VOLTAGE CONTROL UNIT FOR SOUND SYSTEMS IN order to obtain most satisfactory re- sults from sound equipment of the type utilized in theatres it is essential that the input power to the amplifier be main- tained constantly at the rated voltage. Although the various power transformers in an amplifier are usually equipped with primary switches so that the unit can be adjusted for any input voltage within certain limits, if there is a tendency for line voltages to fluctuate, a master power control is essential. A manually-operated line-voltage con- trol unit of convenient size has been an- nounced by the American Transformer Company, This unit was especially de- signed for the purpose described above, is for use in fifty 60-cycle circuits, and consists of an adjustable auto-trans- former with a meter for indicating the voltage supplied to the power circuits of the amplifier. The device will permit of maintaining the voltage at a constant value of 110- or 115 volts, as desired, and may be used where the existing supply is between 90- and 130 volts. Adjust- ment is accomplished by a special multi- point switch which increases or de- creases the potential in 5-volt steps with- out opening the circuit at any time. It has an electrical rating of 750 va. The AmerTran power control Type T-750 is housed in a compact sheet metal box designed for wall mounting. It re- quires a wall space of 614" by 11^" and the overall depth is only 9." The meter employed is a 3" diameter flush- mounted instrument and the control is a large bakelite knob 2^/4" in diameter. AmerTran Voltage Control Unit G-M CELL COUPLING CABLE G-M Laboratories, Inc., announces a new cell coupling cable for use in , sound equipment. This cable has five times the capacity reactance of standard microphone cable so frequently used in sound equipment, and in addition, is highly non-microphonic. The use of this cable reduces the at- tenuation of high frequencies, eliminat- ing to a large degree the frequency dis- crimination of most photoelectric cell amplifiers. This results in increased brilliance of reproduction of voice and instrumental music, so noticeably lack- ing in many types of sound equipment. Those interested in this cable may ob- tain information by asking for G-M bul- letin No. 134. CHEAP COLOR PHOTOGRAPHY SYSTEM SHO^TN IN VIENNA Vienna papers are exploiting with il- lustrations the invention of a local expert, Alfred von Bariss, who says he has per- fected a camera and a process which makes color photography simple and cheap. The camera he manipulated recently before a gathering of reporters is de- scribed as "an ordinary press camera with a good, but ordinary, lens." By the aid of mirrors the light coming through the lens is diverted evenly on three plates inside the box — a yellow plate at the top, a red plate at the back and a blue plate at the bottom. The operation took three minutes, during which von Bariss said: "You may use ordinary panchromatic roll film, film packs, or plates. I am using ordinary films."' Simultaneous Exposure He went on to say that the picture could be taken either by snapshot or by time exposure, but that the three nega- tives must be exposed simultaneously. He then took the negatives to a dark room and developed them, transferring each to specially prepared gelatine sheets, which, he said, could be had for 5 cents apiece. Next he produced a little box in which he placed the gelatine sheets on top of each other over a chemically prepared paper and said: "It is this paper which is my secret, and on which I have worked for seven years. With it you are able to do away with washing and fixing, and can print your colored photographs in ordinary light in three minutes."' He then showed how toning and other artistic effects could be produced on his paper by placing the colored plates at slight angles or in different sequences. He added that any number of colored prints could be made from the colored negatives on his paper, which, he said, cost only a cent a sheet. 16 MM. SOUND FILM A New York manufacturer promises a demonstration of 16 mm. sound-on-film within the next month. The demonstra- tion will include both recording and re- production. ^hc PATENT PAGE THE following digest of patents granted recently was prepared ex- clusively for International Pro- jectionist by Henry L. Burkitt. Mr. Burkitt, B.S. in ch. e., L.L.B., is a former Assistant Examiner in the U. S. Patent Office, a member of the Bars of New York, Pennsylvania, and the Dis- trict of Columbia, practicing in New York City. Any reader desiring infor- mation on any patent, whether abstracted herein or not, or wishing to secure a copy of any patent listed herein, may secure same by addressing Mr. Burkitt in care of this publication. — Editor. Granted August 11, 1931: Motion Picture Film 1,817,977. Motion Picture Film to Paul Favour, assigned to Eastman Kodak Company. This patent relates to a motion picture film used apparently for the production of a fade-out, and then the return to the same or a different picture. It comprises a film having two consecutive film por- tions, each carrying images, the images in each area being of substantially uni- form density. By means of an additional layer, placed over the junction point of the two consecutive portions and a sec- tion of each portion on each side of the junction point, the light may be retarded in varying relation as the film is moved along, the layer being entirely opaque at the junction point. Composite Photography 1.818.354. Composite Photographic Method and Apparatus, to Roy J. Pom- eroy; assigned in part to Paramount Publix Corporation. The patent relates to the production of a composite photograph, that is, the mak- ing up of a photograph by exposing two distinct films simultaneously to the same object. In this case, the object is posi- tioned before a non-actinic ground. One of the films is relatively over-exposed, and this film is developed to produce a substantially opaque mask image of the subject. This film is then used to mask the other film during its exposure to a desired background so that the subject image of the second film may be com- bined with an image of that background. Motion Picture Machine 1.818.355. Motion Picture Machine, to William C. Readeker. The patent is for the combination with the casing of motion picture apparatus, in which a plurality of the angularly re- lated walls are provided with openings through which pictures or images may be projected of a lens holder, provided . . . not ^^clips" in wordy patent language but clear and concise abstracts prepared especially to meet the needs of readers of this publication. for mounting to direct light rays through one of these openings. A deflector is pivotally mounted upon the lens holder and may be moved to intercept the light rays from the lens. The lens holder may be adjusted, with the deflector in intercepting relationship, to deflect the light rays selectively through any one of the other openings. The deflector is pro- vided with means for retaining it in in- operative position on the lens holder so that light may be projected by the lens through the first named opening. Granted August 18: Loud Speaker 1,818,987. Radio Loud Speaker and the Like, to Charles Hugh Duffy. This is a loud speaker in which two or more field windings of different electrical impedances are arranged for actuating the diaphragm. The flow of current through one of the windings may be re- versed with respect to the direction of flow of current in the other winding. Disc Reproducer 1,819,083. Phonograph Reproducer, to William H. Edwards; assigned to American Telephone & Telegraph Com- pany. This patent is for means, combined with the needle holder on an electrical phonograph reproducer, for subjecting the disk of the reproducer to bending stresses, under the control of the needle holder, to vary the impedance of the disk. Loud Speaker Device 1,819,183. Loud Speaker Device, to Israel Ludlow; assigned in part to Al- bert E. Lamb. This patent is for a loud speaker hav- ing the energizing means for the dia- phragm active substantially at the center of the diaphragm. One surface of the diaphragm acts on free and unconfined air. A fixed and substantially non-vi- brating sound deflector is arranged con- centrically with, and spaced away from, the diaphragm and, together with the [35] Edited by RL.BurKitt diaphragm, forms a chamber at least partially enclosing a body of air. An angular passage is formed between the edge of the diaphragm and the deflector so that sound waves may pass out at this point. Picture Screen 1,819,268. Picture Screen, to Homer Saunders. The screen of this patent is made for use in the showing of sound films, that is, the loud speaker would be positioned behind the screen and sound pass through the screen. The screen is of woven wire having a coating of adhesive on most of the strands and leaving open- ' ings between strands. Beads are applied to the screen to cover the adhesive coat- ing substantially. The beads are irregu- larly attached, leaving openings among the beads, which openings, in many cases,, extend completely through the screen. The beads are defined as being of approximately the same size as the mesh of the screen. Distortion Eliminator 1,819,327. Means for the Elimination of Distortion and the Creation of Stere- oscopic Effects in Moving Pictures, to Graves Griffith; assigned to Griffith Camera Corporation, Ltd. The structure of this patent utilizes a screen having a curved picture area. The projector is mounted on a curved track. The curve of the track and the picture area are arcs of concentric circles. Geneva Substitute 1,819,593. Camera, to Royal A. Clapp. The invention apparently is directed to a substitute for the Geneva movement, customarily used. In this case, an ec- centric actuates a member having teeth to engage openings at the edge of the film for the feeding movement. ISew Diaphragm 1,819,659. Sound Reproducing Dia- phragm, to LeRoy W. Stunton; assigned to Brandes Laboratories, Inc. The reproducer includes a diaphragm conical in construction and of mechan- ically stressed thin sheet material having an elliptical periphery. The periphery has a supporting member attached there- to. Sound Screen 1,819,776. Cinematograph Screen, to Jacob C. Heck; assigned to Da-Lite Screen Co., Inc. This screen is intended for coordi- nated sound transmission and is com- prised solely of a single thickness finely woven textile fabric provided with per- 36 INTERNATIONAL PROJECTIONIST October 1931 forations sufficient in number and size to permit the passage of sound waves without blurring, while, at the same time, preserving the light reflecting prop- erties of the screen. Sound System 1,819,820. Sound Recording and Re- producing Means, to Earle L. Kent. This system apparently relates to film having a sound track. In this case, the varying intensities of light from the sound track are changed into electrical impulses, and the electrical impulses into sound waves. An inductive coupling is provided for associating an alternating current with the electrical connection between the means for converting the light variations to electrical impulses, and the means for changing the electrical impulses to sound waves, for producing a tremelo effect in the sound waves. Stereoscopic Camera 1,820,113; Camera, to Gianni Bettini. The patented camera is for recording stereoscopic films. Two separate films are used, with two separate lenses. But a single exposing mechanism operates both lenses simultaneously. The sensi- tized plate is advanced progressively, past the lenses, presenting successive rows of sensitized spaces. Rewinding Mechanism 1,820,731. Motion Picture Rewinding Mechanism, to Max Dainow. The reel of this patent has a spin ex- tending through an opening so that the reel can be freely turned on the pin. The pin has a stop at its outer end. A crank handle is attached to the reel, off- set from the opening, and has' an arm with an opening through which the stop is intended to pass when the stop is par- allel to the pin. A recess is provided for the reception of the crank handle when inoperative. The arm of the crank handle is between the stop and adjacent face of the reel when the han- dle is inoperative and when the stop is operative. Screen Frame 1,820,739. Motion Picture Screen Frame, to John Thomas Heck; assigned to Da-Lite Screen Company, Inc. The patent relates to a collapsible frame for a screen wound upon a spring actuated roller. Granted September 1 : ' Slide Device 1,821,341. Slide Shifting Device, to Austin K. Hanks; assigned to Trans- Lux Daylight Picture Screen. This arrangement is for consecutively shifting into position individual slides from a stack. Fire Preventive 1,821,515 Device for Protecting Films Against Ignition, to Kurt Hoffmann and Max Engelmann; assigned to Zeiss Ikon Aktiengesellschaft. This device incorporates, together with the ordinary fire gate which is operated, in this case, by the loop formed by a broken film band, means for stopping the motor in addition to swinging the fire A Technical and Educational Publication. Devoted to the Western Proiectionist and his Progressive Fellow Craftsman Everywhere. Editor Finn Consratulated It is not often that a projectionist has the opportunity of writing an open letter to an editor and be abso- lutely sure that it will be published. I feel therfore that I am particularly favored as I write this. There is a man in New York who edits a first class projectionist maga- zine which has been fittingly named and is devoted to the craft whole- heartedly. This man's name is James Finn. Most of you have heard of him. Whether or not you know him you are invited to read this letter to him. He will read it the same as you. He hasn't the slightest idea that it is coming. So here goes : Dear Mr. Finn: You certainly made a scoop (as the newspaper fel- lows call it) when you printed the story about the A. P. S. reorganiza- tion movement. It was both timely and eflfective. I congratulate you and your organization — and your contacts on their perfect co-ordination. Your article did everything necessary to create a imtidnal interest in the move, ment. May I presume for a second to be the mouthpiece of the Western Projectionists and thank you for them? As you know the society has prospered in the West and has grown rapidly under the abls guidance of such men as Prank Seavier, Sidney Burton, H. E. Reynolds, Lloyd Litton, Richard Crist, J. T. Moore .and Mar- vin Thoreau These men know how to conduct a society. They have proven that fact beyond all shadow of a doubt. And you may depend upon it, Mr. Finn, that if they are given the opportunity to make their activi- ties national in saope they will make the now congealed wheels of the So- ciety turn as they have never turned before. These fellows are hustlers who h^ve the profession at heart. Their earnestness and sincerity are undeniable. Their ability is proven. Where can a better, more capable group be found to bring the ship of concerted academic effort safely into the port of progress? You have been fair in representing all sides in projectionists' controver- sies. So fair, in fact, that I for one believe that fairness with you is not an effort at all, it is just a part of your make up. Every projectionist in the country should know how for- tunate they are in having your type of man in your important position. Sincerely yours, Wallace G. Crowley. Reproduction of an open letter to James J. Finn which appeared in a recent issue of "The Loudspeaker^^ organ of the West Coast A. P. S. gate or shield into position. Means are provided allowing for resetting of the parts after such stoppage, and also a protecting plate is arranged to prevent loose ends of the broken film from be- coming entangled in the mechanism. Sound Radiator 1,821,547. Sound Radiator, to Ralph L. Hartley; assigned to Western Elec- tric Company, Inc. This sound radiator has means for ten- sioning it and to drive it at every point along its edge. ^'Delusion Pictures" 1,821,626. Producing Projection Pic- tures, to Fritz Fleischer. This apparatus is to produce delusion pictures. Moving pictures are directed onto the same screen with the picture from a plate. The same light source, by a reflecting medium, is utilized for pro- jecting the two pictures. Multicolor Film 1,819,981. Multicolor Cinematograph Film Material, to John Edward Thorn- ton. This relates to a particular type of film for multicolor photography. A mosaic pattern of two longitudinal stripes of different colors, two colors- being presented in each stripe, is the structure specified. HALF-HOUR PHONOGRAPH DISC Before such eminent critics as John: Philip Sousa and Dr. Leopold Stokowski„ a new long-playing phonograph record capable of reproducing an entire sym- phony has been demonstrated for the first time by the RCA Victor Co. Production, of the new record has begun, it was an- nounced, and program transcriptions will last a half hour, using both sides of the; disc. The long playing feature is ob- tained by slowing down the machine's; turn-table speed and doubling the num- ber of surface grooves. The discs are made of a new composi- tion a fifth as heavy as that used in pres- ent records. The surface noise from the needle is reduced to less than half that, on the ordinary record. Stokowski heard,, on the new record, his Philadelphia Or- chestra play Beethoven's Fifth Symphony^ and praised the reproduction. CHEAP GERMAN RECORDER The German motion-picture industry" has shown great interest in the develop- ment of a new sound recorder, according^ to the American Trade Commissioner in Paris. This system uses Braun valves and requires only one-tenth watt for op- eration. It is consequently possible to. rent or sell such recorders at much lower prices than those of the major electricaE concerns. Small producers are particu- larly interested, as they hope to be able to stay in business if it is possible to rec- ord films with a cheap system. October 1931 INTERNATIONAL PROJECTIONIST 37 CLKVKLANP CHAPTER. AMKRICAN PROJJ^CnON (SOCIETY NO. 113 CLBVEUUiD, n ^/'^/&f ^9 ^S^j^i^i/r^Y^ «-^4i2 $ ^-r^y-^ TO CXJ4VVtlA>ri> OMAJ-XBH - i MUUIOKN PROJKCTION »OCl Reproduction of check in payment for one year*s subscription for every member of Cleveland Chapter !So. IS of American Projection Society. This cheeky one of many tendered prior to publication of the first issue, constitutes a splendid personal tribute to James J, Finn and is jn- dicative of the esteem in which he is held by the craft. INTERNATIONAL Edited by TODAY more than ever the projectionist craft needs a real organ of expression to champion its cause. The craft today is the beneficiary of an unrestricted amount of advice relating to what it should and should not do emanating from self- appointed oracles who exhibit an amazing ar- rogance by demanding that the craft extend to them its support and thus insure a continuance of their God-given (?) franchise to serve the craft by taking something and giving nothing. This service consists of telling the craft what it should do without even touching upon how to do it. . . . Enough. INTERNATIONAL PROJECTIONIST wiU institute at least one radical innovation in the technical motion picture publishing field in that it will pay for its articles — and pay for them upon acceptance without regard to the date of publication. This statement may be regarded as an open invitation to all those who feel that they have something to say and would like to be recompensed for saying it. Dissertations having their source at company publicity desks will have to be explicit in stating PROJECTIONIST James J. Finn why as well as what; otherwise they will be de- posited in the wastebasket. Products of inferior merit wUl be exposed as such as readily as will praise be given to meritorious articles. Comment from readers on either editorial content or equip- -ment will be given editorial preference. Craft news and developments affecting the craft wUl be accorded ample space. Individual effort of benefit to the craft or reflecting credit on the craft will be publicized; but copy which constitu- tes merely a personal "puff" will also be deposited in the wastebasket. Local Union social affairs are nice things in themselves, but they make poor editorial copy unless a stray speech or so thereat contains something of value. Organization elec- tion results are interesting — at times — but nothing beyond a list of the officers is of much interest — that is, to us. With the foregoing as a basis on which to work, our editorial policy should produce results and commend itself to our readers. Use this blank to record your sub- scription and insure receipt of all copies- If you are already a subscriber, pass tdong this blank to your brother projec- tionist. 1 Year . . $2.00 2 Years . . $3.00 INTERNATIONAL PROJECTIONIST 1 West 47th St. New York, N. Y. Date 193 Enclosed is $ for year(8) subscription to begin with issue. Name Address City State Local 38 INTERNATIONAL PROJECTIONIST October 1931 Notes from the Science World {Continued from page 32) sor Schuneman, opens wide and inter- esting prospects for the future. By means of a single X-ray examination, it will among other things be possible to find out whether or not a human voice is fit for training and, thus, to save money and time to a number of hopeless candidates. CAT'S EAR AND SPEAKER YIELD NEW HEARING DATA Evidence that everybody might be en- abled to hear about 50 per cent better than normal if a way could be found to press continually on a certain spot in- side the ear, has been presented to the American Medical Association by Dr. Walter Hughson and Dr. S. J. Crowe, of Johns Hopkins University, Baltimore. The critical spot is the so-called "round window," a small spot of translucent membrane through which the sound waves leave the three small bones of the middle ear and pass into the coiled, liquid-filled tube of the inner ear where the actual hearing is done. Dr. Hughson and Dr. Crowe operated on cats under a surgical anesthetic and placed tiny metal electrodes in contact with the nerves leading from the ear to the animals's brain. These electrodes then were connected to an amplifier like those used in radio,' so that the nerve impulses generated by the ear machinery could be magnified and measured. It even was possible to send these electric impulses from the nerves over wires to another room and to reproduce them by a loud speaker, so that persons in this distant room heard through the cat's ears whatever would have been heard by that aminal had it been conscious. With this apparatus working, Dr. Hughson and Dr. Crowe then reached into the middle ear of the cat and pressed on the tiny round window so that it was bent inward, increasing the pressure of the liquid in the innermost part of the ear. Hearing always was increased, usually by about 50 per cent. This happened both with normal cats and with those already partly deaf. Probably continual pressure on the round window would be dangerous to the hearing machinery even if it were possi- ble to maintain it. No hope is held out that increase of inner ear pressure will be a practical cure for deafness. Never- theless, the discovery that hearing is bet- tered by pressure, even above what has been called normal, may lead to other discoveries of more practical value. DR. INNES' SYSTEM OF STERE- OSCOPIC MOTION PICTURES Dr. R. T. A. Innes, former South Af- rican Union astromer, has devised a sys- tem of stereoscopic film projections by which, he says, it will be possible to see figures and scenes in lifelike relief. The problem has confronted photographers practically since the invention of motion pictures, but hitherto attempts at solu- tion have been based upon the projecting camera itself. Dr. Innes says his inven- tion, for which world-wide patent protec- tion has been obtained, is founded on a special appliance fitted near the screen. Secret experiments conducted at Johan- nesburg in the past six months resulted in the adoption of fairly rough models used at the outset, improvised by photo- graphic firms to the needs of commercial exploitation. The final form in which the invention will be exploited is still unde- termined. An important feature in the innovation is the fact that changes in the methods of taking pictures will not be necessary. The Innes discovery was due to an ac- cident. While visiting a cafe motion pic- ture some time ago he noticed an optical effect on a sheet of glass on one of the walls, giving an extremely lifelike stereo- scopic image. He immediately grasped the possibilities and was able to obtain a similar effect by using an ordinary home film projector. FIRST ORDER FOR FILM When Thomas Edison heard of George Eastman's success with film, he sent a $3.50 money order to Rochester with a request for fifty feet of film, one inch wide. That order, for the first strip of motion picture film, is still in the files of the Eastman Kodak Company. 24 experts explain sound-recording and projection HERE is a book needed by every man connected with the practical side of the talking picture industry, in theatre or studio. Written by the men who taught the screen to talk it covers every phase, both technical and practical, of sound recording and reproduction. Recording Sound for Motion Pictures Published for the Academy of Motion Picture Arts and Sciences Edited by Lester Cowan 404 pages, 6x9, 229 illustrations, $5.00 Answers many questions on: — practical technique of recording — booms, blimps and microphones — recording systems — film laboratories — assemibling the talking picture — reproducing systems — practice and problems of sound projection 'X'WENTY-four sections, each written by a recognized authority and -*- specialist in his field, present an authoritative description and ex- planation of the fundamental principles involved in recording and repro- ducing sound for motion pictures and their practical application in the studio, on location and in the theatre. Everything essential or important is covered, from the fundamental nature of sound, down to the practical aspects of volume control, theatre acoustics, and other everyday problems of sound projection. Order from INTERNATIONAL 1 West 47th St. PROJECTIONIST New York, N. Y October 1931 INTERNATIONAL PROJECTIONIST 39 SCREENS — THEIR SELECTION AND MAINTENANCE t Continued from page 29) spectators sitting close to the screen. The eye can satisfactorily accommodate itself over an angle hardly more than 45 de- gress, so that the distance of the front row from the screen should be approxi- mately 15 inches for each foot of screen width. For a 15-foot picture, a distance of at least 18% feet should therefore be provided. The size of the picture should also be determined by its distance from the rear seats. The width of the screen should be approximately one-sixth the distance from the screen to the rear seats. For a distance of 120 feet, therefore, a 20- foot picture should be provided. Fig. 4 shows curves which may be used in de- termining the proper size of the picture, and the length of throw should also aid in determining the size of the picture. Here, however, the character of the screen must be considered. If it is of the beaded type, in a house adapted to it, a considerably larger picture can be used because of the increased brightness of the picture as seen from most seats. It is a fact that the smaller the screen, under a given set of conditions, the brighter it appears. For this reason there is a definite maximum limit to the size of the picture when using Mazda or low- intensity arc lamps of 18 to 28 amperes. Practical tests have determined these sizes to be as shown in Table B. This table is based on the best figures available at this time regarding screen illumination, which varies from 3 to 7 foot-candles with the shutter in operation, for a picture of average size. For hi-low and high-intensity light sources, there seem to be no limitations beyond the rea- sonable ones already placed. It should be remembered that when a given light source at a given distance is used to project on a larger screen, the screen brightness will be lessened, just as a 25-watt lamp in a small room will light a threatre auditorium much less brightly. A 12 by 16-foot screen having an area of 192 square feet is almost twice as bright as a 15 by 20-foot screen having an area of 300 square feet, under the same conditions. Therefore, if a screen is not already more than bright enough, a change to a larger screen should not be considered unless it is to be changed to the beaded type. Practical showmanship is responsible at times for causing exhibitors to do things that may not be technically cor- rect. The excitement about large pictures (which was accomplished practically, but not satisfactorily, by merely changing the sizes of screen and picture ) , caused the exhibitors to feel that it is necessary to have a larger screen than is ordinarily desirable. The maximum size of picture, except in unusual cases, should be 18 by 24 feet. If a screen modifier is to be used, there must be suificient difference between the sizes of the small and large pictures to make the effect worth while. A change from a 20 by 26-foot picture to a 24 by 36-foot picture would not be desirable; however, a change from a 15 by 20-foot standard picture would pro- vide the desired effect. Position and Surroundings Local conditions determine to a great extent the location of the screen. In gen- eral, it may be said that the illusion of reelism is best maintained by placing the screen either as close to the floor as possible or not more than 18 inches above it. When possible, the floor of the stage on the house side of the screen should be covered or painted with a dark non- reflecting, non-glossy material, as the stage floor produces annoying reflections of the picture. The screen should, of course, have a Hoffmann - Soons Every known quality necessary in producing perfect projection is embodied in perfection rheostats. PERFKLTION SOLDERLESS ADJUSTABLE LUGS Heavily Constructed Will take wire sizes from No. 4 to No. 4/0 Recognized as the highest standard everywhere [ Sold by all branches of the National Theatre Supply Co., Sam Kaplan, New York; Continen- tal Theatre Accessories, and by your dealer. ] The Only Union-Made Rheostat We Build Rheo- stats for Special Requirements. Communicate With Us Direct. There Is No Ob- ligation. R HOFFMANN - SOONS ELECTRICAL & ENGINEERING CORPORATION 387 FIRST AVE., NEW YORK HE OS TATS 40 INTERNATIONAL PROJECTIONIST October 1931 mask around it to properly frame the picture, and to reduce the "jumping" effect which occurs when poor film or poor equipment is used. This mask is usually a black cloth free from gloss, but at various times a less absorptive material has been advocated to reduce the sharp contrast between the frame and the pic- ture. Because of jumping, it is not desir- able to use a light material next to the screen; the desired effect may be ac- complished by a graded surface, with the darkest material adjacent the screen. Sometimes screens are tilted in order to correct for keystoning, or, with silver screens, to redirect the light to better advantage. This is a difficult problem, and furthermore, it might be stated that a tilted screen collects more dirt than an upright screen. Tilting should be re- stricted to silver screens. Keystoning and side-view distortion are due to large projection angles or poor perspective, and cannot be corrected by using a modi- fied aperture plate. Side-view distortion cannot be corrected but can be avoided to a certain extent by keeping the screen as far from the front seats as possible, and by eliminating the wide front seats. The principles of correct lighting for theatres are so well known that only a few of them will be mentioned here: (a) The intensity of illumination should gradually diminish from the street to the audi- torium, so that the eyes may gradually become accommodated to the low intensities. (b) Auditorium lighting should be of low intensity. The auditorium should be only suffi- ciently bright to permit patrons to readily locate empty seats, and not so bright that they will be distracted by movements of other people. Less light is needed in the front of the audi- torium. (c) All light sources should be diffused so that no points of considerable brightness are ap- parent, and no lights should be near the line of vision when viewing the picture. (d) The light should be so deflected that as little as possible falls on the screen. Installing the Screen The manner of installing screens has an important bearing on the results ob- tained with them and the economies ef- fected. A few rules for installing screens will therefore be given. However, when manufacturers' instructions are available, they should be followed to the letter. (I) Whenever possible, and wherever a screen is smaller than 15 by 20 feet, the screen can best be installed by as- sembling the frame on the stage or on the seats with the top toward the place the screen is to be. (a) Lace the left side, which is the top screen surface, on the roll. Follow with the top and bottom of the screen, and then the right-hand side. (b) When the screen is in place, tighten the laces ; in the case of a beaded screen, where there is no need for ex- treme tightness, do not stretch other than to remove the wrinkles. (2) If the frame is already in an up- right position, a line should be fastened to the shipping roller and the screen should be raised into place on the left side of the frame, rested on the bottom rail, and fastened by the line to the top rail. Care should be taken not to crush the screen or allow the material to sag from the roller. (a) With small pieces of line, start- ing at the corner grommet, tie the screen into place at the top grommet, unrolling the screen as each grommet is tied to the frame. (b) Lace the top of the screen after it is temporarily in position; then lace the bottom, and finally the sides. (c) When the lacing is finished, tighten it gradually to free it of excess wrinkles. Do not stretch tightly. Maintaining Screen Surface There are four phases to the mainten- ance of screens; one pertains to the preventing of dirt from accumulating on the screen; another to freeing it of ex- cess dirt; the third to a complete and thorough cleaning of the screen; and the fourth to the renewing of the surface. The final objective is to keep the screen surface as nearly perfect as possible at all times by taking all precautions and by systematically attending to it. The surfaces of sound screens have 1 What does Television mean to You? H 1, ERE i» a new book that gives all the facts about this new and amazing offspring of radio. Avoiding technical terms it follows the development of television right up to date, explains principles, methods and apparatus, and weighs for you the problems, possibilities and probabilities of television as a commercial tool and a form of entertainment. Just Published TELEVISION by EDGAR H. FELIX Radio Consultant 276 pages, S^x8, illustrated, $2.50 ' HAS television arrived at last? €an present broadcasting and receiving equipment be adapted to television? WiU television of the future come by air or wire? This book from beginning to end was written expressly to supply reliable answers to these and hundreds of other questions you may have asked regarding television. With many explanatory illustrations and diagrams it gives a thorough background of technical facts — then makes plain their importance from the standpoint of the experimenter, the commercial operator, the broadcaster, the "listener-in." Order from INTERNATIONAL PROJECTIONIST Covers television such as: topics 1 West 47th Street New York, N. Y. — ^has Television really arrived ? the HOW and WHY of Television. •—unsolved problems of Television, ^—possibilities of 100-line system, ——latest synchronizing methods, —the human eye in Television. ^— will future programs come by air or wire? —new developments affecting receiver design, -—future progress of Television. October 1931 INTERNATIONAL PROJECTIONIST 41 very dissimilar characteristics. Some are very rough, some smooth, some hard, and some are sticky. The perforations add much to their ability to collect dirt, and porosity of the surface adds to a some- what lesser degree. The circulation of air through the openings also makes it easier for the screen to collect dirt. Silver screens collect dirt, just as do the beaded and white screens; furthermore, they be- come tarnished, resulting in a lowered re- flection value. A hard white screen is better than a sticky one from the main- tenance standpoint. Accumulation of Dirt The amount of dirt deposited on the surfaces of the screen depends on the atmosphere of the house, on the neigh- borhood, on the circulation of air in the theatre, and on the precautions taken to protect the screen. The first step to be taken toward keeping the surface clean is to determine whence the dirt comes, and to alleviate the difficulty at its source. The following are the more obvious sources of dirt; and remedies: (1) Dirt falling from overhead and draperies. Thoroughly clean overhead, side draperies, and masking. Prevent travelers from brushing the screen. (2) Stirring up of dirt by cleaners. Cover the screen at night when not in use, even though with only the cheapest kind of material. (3) Circulation of air through the screen. Close doors, etc., which cause drafts, and back the screen, close to the horns, with a neutral gray material to prevent air from circulating through the openings. Even after taking all these precautions, the screen will collect dirt. Inspection will indicate whether the dirt is dry or greasy and, therefore, whether the screen can be brushed. If the dirt is dry, the screen should be brushed with a long- handled special screen brush. It is also well to vacuum-clean the back of the screen once a week. The brush should be kept clean. Cleaning the Screen No satisfactory method of cleaning screens has been suggested as yet. It is possible to clean small samples of screen material, but the cleaning of screens in- stalled in the theatre or when returned to the factory is not practicable. The screen sags, and water soaks in at the perforations, causing deterioration of the surface. Streaks result from unequal drying. The soap causes the screen to become yellow after a few days. If screens must be cleaned, however, there are certain instructions which, if fol- lowed, will produce better results than are usually obtained: (1) Great care must lie taken; (2) Lise two buckets, one for the cleaning International Photographer Is a finely printed and beautifully illus- trated monthly magazine owned by the West Coast Cameramen's Union In all matters concerning the profes- sional motion picture photographers of the country it is the official organ It is designed to appeal to amateur followers of 16mm. cameras as well as to the most advanced technicians The columns of the magazine recog- nize the close relationship between the photographer and sound recorder If your news or kodak dealer does ' not carry the magazine on its coun- ters write for a sample copy to INTERNATIONAL PHOTOGRAPHER GEORGE BLAISDELL. Editor 1605 North Cahuenga Avenue, Hollywood, Calif. 25 cents a copy $3 the year and the other for clean solution water ; (3) Keep the water and solution clean at all times; (4) Free the surroundings and screen of excess dirt before cleaning; vacuum preferably ; (5) Use soft sponges and keep them dry. so that no water will run down the screen ; (6) Work from the bottom to the top of the screen ; (7) Use plenty of light. Replacing the surface of diffusing screens by spraying is receiving consid- erable attention. When carefully done, and when the proper material is used, a satisfactory job may be possible. The material should have a hieh reflection value, and should become yellow as little as possible. Here again, the screen and its surroundings should first be cleaned thoroughly. In conclusion, in order to properly select, purchase, install, and maintain a screen, the following outline should be carefully followed: (1.) Decide on the proper type of screen for the house. (a) If the prelection angle is less tban 20 degrees and the house is not extremely wide, use a beaded screen. (b) I: the projection angle is greater than 20 degrees and the house is extremely wide, use a matte screen. 42 INTERNATIONAL PROJECTIONIST October 1931 (2) Choose the best screen surface of this type. (3) Analyze the house conditions and select the proper size of screen. (4) Install the screen properly, following the manufacturer's instructions. (5) Permit no circulation of air through the screen. (6) Cover the screen when not in use. (7) Brush the screen regularly once a week, with the proper kind of brush. Discussion : President Crabtree: How are the screens cleaned? If the brush method is used, how are they brushed ? Is the screen taken down from its position or is it brushed in place? Also, how is the screen resurfaced? What is the cost of resurfacing in comparison with the cost of the screen Is it worth while? Mr. Falce: The screen is cleaned in position with a very soft, long-handled brush. Cleaning is very simple, but is often neglected. Some one in every theatre should be given the responsibility of keeping the screen clean. The cost of taking down the screen, packing and shipping il to be resurfaced, and mounting again is so great that it is better to clean the screen in position. Screens may be resurfaced in a number of ways, the spray process being the most satisfactory. The cost of this treatment varies in different places, from 10 to 20 cents per foot. A new screen may cost from 2% to 4 times the cost of resurfacing, depending upon the amount of surface to be treated. Screens can be resurfaced satisfactorily, but in general, the process is not satisfactory, as the material used for resurfac- ing becomes yellow and is not always put on uniformly. President Crabtree: What is the effect of spraying a beaded screen? Is it cleaned by spray- ing, or were you referring to diffuse screens? Mr. Falce: I was referring to diffuse screens. No good is accomplished by spraying a beaded screen, as the spraying causes the beads to lose their directive qualities. In general, it is ex- tremely difficult to properly clean screens on account of the wide expanse of the flat surfaces. Beaded screens can be cleaned satisfactorily, but>^ the process is very complicated. President Crabtree: Could some solvent be used for cleaning the beaded screen? Mr. Falge: To a certain extent; but the sol- vents that have been tried have loosened the adhesion of the beads and so such methods have not been found satisfactory up to the present. President Crabtree: The matter of standard- izing screen sizes is very important. Has' this matter been brought to the attention of the Projection Screens Committee? Mr. Falce: Yes, but nothing definite has been done about it as yet. Mr. Schlan'cer: The information given in this paper referring to the proper distance between the seats and the screen is very important and should be referred to the American Institute of Architects. In relation to the shape of the screen, I suggest that perhaps Mr. Dieterich mig' t say something about the restful physiological effect of the 3 to 5 ratio on the human eye. Mr. Dieterich: Yesterday I briefly mentioned the fact that there is a minimum distance re- quired between the eyes and the screen for comfortable viewing the picture. To go a little deeper into the discussion we must consider the sight characteristics of the eyes, which when plotted, assume a peculiar egg-shaped form for each eye. The combination of the two charac- teristics produces a more or less heart-shaped curve for the combined characteristics of the two eyes — i. e., for binocular vision. If we inscribe a rectangle into the combined characteristics we are led to the classical ratio of height to width of 1 to 1.6. As long as we have to change the proportions of the visible picture — which we must do sooner or later — we should consider the esthetic demands, because they control to a great extent the reaction of the public, which again influences box-office returns. As long as it is necessary to change the dimensions, I am en- deavoring to advocate that we should change in accordance with this ratio. There will be a number of technical difficulties, and problems to overcome, but they will have to be overcome sooner or later, in any event. The Standards Committee has suggested a 50-mm. width for production reasons, but we can just as well use the proper proportions for this width as for any other. Mr. Schlanger suggested that when one sits in front of a screen that is 40 feet H. R. Van Deventer Patent Attorney Specialist on Motion Picture Devices Sound Recording and Reproduction Small Electrical and Mechanical Devices 342 Madison Ave., New York, N. Y. wide, he may come closer than 40 feet. However, this would not place the screen within the "easy" range of the eye. The eye must exert an effort to encompass an angle greater than 60 degrees and although our total vision is limited only by about 180 degrees, it becomes a painful effort to use it to its full extent. .A.long the horizontal axis of vision, the "easy" range is normally 30 degrees on each side, and along the vertical axis about 10 degrees above and 20 degrees below the horizontal. If the scheme of Mr. Schlanger is in accordance with these physiological facts, he will find that the spectator will enjoy the picture more than in the past. As to the question of depth perception, the recog- nition of depth in the wide picture is due to the fact that when one looks at a wide screen, the distances to the edges of the picture are per- ceptibly greater than the distance to the center, and the eye has to accommodate itself to such different focal values. Therefore, the only means of perception, which is by the final nerve center, would cause a reaction, resulting in a muscular effort to accommodate the eye. Therefore, the wide picture has certain disagreeable effects for the present front seats, but which lessen as the distance from the screen increases. The minimum distance between the screen and the front seats, should not be less than the width of the picture. Mr. Falce: The ratio you suggested is close to the 3 to 5 ratio which I mentioned previously. Mr. Jones: There was one statement in Mr. Falge's paper I should like to question. In dis- cussing the diffusing type of screen he stated that the brilliance of the screen depends upon the viewing distance. I cannot see why the argu- ment applies to the diffuse type of screen and not to the beaded type. It is quite possible that the brilliance of the screen — that is, the apparent brightness — is to a certain extent influenced by the angle of the screen and by the surroundings. I think it is quite possible — and I know it is true — that whether the screen appears to be more brilliant at one distance than at another will depend upon the surroundings of the screen. I think we should recognize that that character- istic, which may be a true phenomenon, is a characteristic of all types of screens, and I can- not see that it is a characteristic of a diffuse type of screen any more than of any other. Mr. Falce: What I meant to convey was that this effect is more pronounced in the case of the beaded screen. I referred to it briefly in connection with the beaded screen. As far as the surroundings are concerned, if too much light is present, the pupils of the eyes become smaller and the screen does not appear as bril- liant as one would like it to be. Mr. Otis: Have any measurements been made on the diffusiveness of the screens to color? Mr. Falce: Do you refer to a particular one ol the three types, or to all screens? I do not believe that such measurements have been made. Mr. Schlancer: Referring to the shape of the picture and the desirability of retaining the S to 5 ratio, it is possible to change the shape of the screen throughout a picture so as to present different geometrical forms — triangu'ar, rectangu- lar, circular, etc. I understand that some work has already been done along that line. Mr. Dieterich: Madame Ducat, the only fe- male member of the Legion of Honor, has in- vented a new "panel" aperture. Her idea is that everyone who has a sense of the artistic frames a picture or composition according to the com- position, and does not take the frame and fill it with the composition. The frame should be un- der the control of the cameraman so that he may instantaneously alter the picture frame as de- sired. This does not depart from the 1 to 1.6 ratio for the shape because this ratio is an esthetically fundamental one from which any number of frame sizes can be developed. Her idea of changing the frame size according to the action has been successfully used because she understands the correct use of the panel frame. THE BOOK OF THE MONTH THE BOOK OF THE YEAR THE BOOK of the MOTION PICTURE INDUSTRY SOUND PICTURES AND TROUBLE SHOOTERS MANUAL By JAMES R. CAMERON and JOHN F. RIDER Introduction by WILLIAM F. CANAVAN (Inter. Pres. I.A.T.S.E. & M.P.M.O.) LATEST MOST COMPREHENSIVE AUTHENTIC BOOK ON THE SUBJECT PUBLISHED USED BY THE MOTION PICTURE INDUSTRY THROUGHOUT THE WORLD AS THE STANDARD AUTHORITY USE THE COUPON A COMPLETE GUIDE for TROUBLE SHOOTING U. S. DEPT. OF COMMERCE (MOTION PICTURE SECTION) These books (Cameron's) should be in the possession of every projectionist, theater man- ager and everyone interested in receiving au- thentic information regarding the application of sound to motion pictures. Cameron's books are a wrorth while contribution to the motion picture industry. THE LEAGUE OF NATIONS (CINEMATOGRAPH INSTITUTE) "Mr. Cameron is one of the very limited number of technical writers on cinematography really w^orth reading." "His books are of particular interest be- cause, although essentially technical and based upon theoretic principles, they are nevertheless Avithin the grasp of any reader wishing to ac- quire a knowledge of the sound-film in all its aspects." ENDORSED BY THE TRADE PRESS THROUGHOUT THE WORLD 7 50 The making and showing of Sound Motion Pictures, Sound- On-Film and Sound-On-Disc is covered thoroughly and in an expert manner. The book is written so that the subject mat- ter is easily understood. Explains in detail the construction, operation and care of sound recording and reproducing equip- ment. Every known trouble to sound equipment is listed in this book with full simple directions for its cure and explana- tion as to its cause. A Complete List of Our Motion Picture Books Sent on Request. YOU_WANT THE BEST— THEN ORDER A CAMERON BOOK CAMERON PUBLISHING CO., WOODMONT, CONN., U. S. A. GENTLEMEN: HERE IS MY SEVEN-FIFTY. SEND ME A COPY OF SOUND PICTURES. NAME ADDRESS BRILLIANT SOUND Reproduction INSIST ON rSTTRONI PHOTOELECTRIC CELLS 79-A for estern Electric, a ph o n e , and Id ey equip- The HEART of TODAY'S BEST SOUND EQUIPMENT There's a VISITRON CELL for Every Make of Sound-on-Film Equipment . , . manufactured by LABORATORIES IH 1737 Belmont Avenue, Chicago, 111., U.S.A. Export Offices: 15 Laight St., New York British Offices: Claude Lyons, Ltd., 40 Buckingham Gate, London, S. W. I., England The projectionist who is critical about the performance of his sound equipment and is satisfied only with the best possible reproduction has only to try out a VISITRON PHOTOELECTRIC CELL. Instantly he becomes a con- vert to super cell performance and afterwards will accept no substitutes. Crystal clear, perfectly defined, brilliant tone value . . . due to Visitron's Higher Sensitivity. Free- dom from trouble; absence of aggravating variations; positive Constancy during their longer life . . . guaranteed for a year. Order Visitrons now from your National Theatre Supply Company branch or representative. I ift fnfemofiono// )JECTI0NIS1 £c//f€c/ hy James J. Finn RACON SUPERIOR SPEAKE Throughout the world leading Sound equip- ment manufacturers have placed all types and makes of horns, speakers and units on exhaustive laboratory test. Engineers in nearly every case have chosen Racon Prod- ucts as being the acoustically perfect, most adaptable sound reproducers for Sound distribution. Whether or not you are satisfied with your present sound reproduction RACON assures you there is still room for improvement. Let us study your problem. Racon's Electro dynamic horn units are recognized as the finest that money can buy. Natural tone quality in any volume with Racon! GIANT ELECTRO Dynamic Horn Unit Continuous operating capac- ity: 7-10 watts. Peak load capacity: 25 waits. No. 6320 Horn, illustrated above, has an air column chamber greater than 10 ft. Depth 37 inches. Bell 76x28 inches. Equipped with cast aluminum throat, patented self supporting frame, bronze coupling. A wide angle horn particularly adapted to distribute sound in theatres of extreme width — 50 feet or greater. Weight 60 pounds. Racon horns and units are covered by U. S. Patents Nos. 1,507,711, 1,501,032, 1,577,270. 73,217, 73,218, 1,722,448, 1,711,514, 1,781,489. Write for Complete Catalog Racon Electric Co., Inc. 18 Washington Place New York London, England Toronto, Canada Vol. 1, No. 2 [November, 19 A magazine devoted to better visual and sound 25c. a c S2.00 a 5 For better quality picture and sound r e production Lightweight — yet sturdy, rigid and durable The Projection Reel Designed by a Projectionist for Projectionists l\l O seams, no brazing and no welding to break open or come apart when rewinding or while in the projector. Made of a special aluminum alloy which results in a lightweight yet sturdy and rigid reel. No rough edges to cut the fingers or damage the film. The True Reel for Projection Sold by All Leading Dealers PRICES: 15 in. reel with 5 in. hub $3.00 each 11 in. reel with 5 in. hub $2.50 each Manufactured by W. & W. Specialty Co. 159 West 21st St. New York, N. Y. November 1931 INTERNATIONAL PROJECTIONIST ff)//ef/nof//o/na/ POECTK Edited by James /• Finn Volume I NOVEMBER 1931 Number 2 Monthly Chat Announcement Sound Projection: Theory and Practice 7 R. H. McCuLLOUGH Halation: Its Cause, Effect and the Remedy 9 H. Parker and J. I. Crabtree Color in Motion Pictures M. ROBACH 11 Characteristics of G-M Visitron Photo Electric Cells 12 Evolution of I. A. Bulletin R. 0. Baker 14 Recurrent Reproducer Noise 15 New 3x4 Standard Aperture For Projection 16 Dividends From Pennies 20 Kendall Emerson, M. D. Editorial Page 21 The Art of Continuous Cinema- tography 22 William C. Plank Mathematics for the Projec- tionist 24 Siegfried S. Meyers Alliance Items 26 Control of A. P. S. Passes to West Coast Group 27 Sound and Television School "Racket" 28 James J. Finn Film Mutilation Television News Notes The Patent Page 30 31 33 H. L. BURKITT Notes from the Supply Field 35 Mechanical Hints 37 Notes on the S.M.P.E. Progress Report 39 Miscellaneous Items Technical Hints News Notes Published Monthly by JAMES J. FINN PUBLISHING CORP. 1 WEST 47th STREET, NEW YORK, N. Y. Advertising Manager: James Beecroft Circulation Manager: Ruth Entracht West Coast Representative Hallet E. Cole, 846 South Broadway, Los Angeles, Calif. / Yearly Stjbscbiption: United States and possessions, $2 (two years, $3) ; foreign coontries, $2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Entire contents copyright, 1931, by James J. Finn Publishing Corp. International Projectionist is not responsible for personal opi- nions appearing in signed arti- cles in its columns. Cover design by Morgan Bryan. Printed by Roy Press, N. Y. MONTHLY CHAT ITS technical excellence assured from the very start, Intertaional Projec- tionist, looks for new worlds to con- quer. And finds them. The typograph- ical beauty of our first issue, which in- duced so many fine comphments (for which we thank you one and all), has set eur contemporaries to hustling. One new cover has already appeared; and we hear rumblings of still another new cover, with an accompanying slight re- duction in overall size. This last move is one near and dear to our own heart (don't mention it). This service by us in the cause of ART is performed with cheerful mien; but we can't withhold the observation that a mere new cover or a change in overall size will fail miserably in match- ing the high editorial standard we have set. GREAT chunks of publicity were spread over the landscape of this fair country by the recent demonstration of television at the Broadway Theatre in New York. Most of this pubhcity was along conventional lines: "television arrived" and all that sort of bunk. Noth- ing to worry about, gentlemen. Ab- solutely nothing. HARDLY a week passes now but what a new indication is had of the in- creasing interest of the industry as a whole in the quality of the image on the screen. Sound production and repro- duction has had more than its share of attention, to the obvious neglect of pic- ture projection. Who is there who will say that the picture in the average the- atre today is anything but terrible? No one. Pictures that appear on theatre screens these days would have been laughed at in, say, 1925. Now, however, the "big boys" are wak- ing up to the serious consequences of a poorly projected picture. Plans are afoot to improve the screen image. Who knows? the "big boys" might even buy a few dollars worth of equipment. Any- how, they are once more aware of the existence of a projection room in the theatre. THE ever alert Academy of M.P. Arts & Sciences is sponsoring new aperture standards for cameras and pro- jectors, complete details of which are printed in this issue. The proposed new projector aperture is .615 x .820, which size appears to us to be very close to the safety mark. Whatever standard is finally adopted, projection will benefit greatly, and Portland, Maine, and San Francisco will once more be in agree- ment as to picture size. Score another for the Academy. INTERNATIONAL PROJECTIONIST November 1931 TWO NOTEWORTHY ACHIEVEMENTS IN PROJECTION EQUIPMENT Complete rear shat- ter attachments show- ing framing device, shutter adjusting de- vice, framing light, hinged eye shield, cooling plate, fire shutter lever and gate opening device. B. & S. Rear Shutter reduces aperture heat by 70%, minimizes effect of warped and buckled film, and keeps film free from dust and dirt. Exclusive blade feature of this shutter keeps hot air from film and insures constant supply of cool air around the aperture. The results of a test by the Massachusetts Department of Public Safety in a Boston theatre on Janu- ary 19, 1930, are as follows: Without B. & S. Rear Shutter Aperture Heat: 1250° F. With B. & S, Rear Shutter Aperture Heat: 340° to 350° F. Installation can be made in one hour on any single- or double-bearing projector mechan- ism, w^ithout any cutting or drilling. Periodic oiling is the only maintenance requirement. Rear shutter equipment includes cooling plate, framing device, shutter timing adjust- ment, and a framing light. A hinged eye shield permits easy accessibility to the me- chanism. B. & S. Change-over consists of two shutter blades contained in a housing de- signed for attachment to the cone of the lamphouse and operates on either A.G. or D.G., at 110 to 125 volts. Novel design eliminates any possibility of double exposure on the screen, and makes the change invisible to the audience. B. & S. Change-overs operate eflBciently on either A.G. or D.G., but coils for the proper current will be supplied on specification. Goils of the B. & S. Ghange-over will stand up under heavy overloads and w^ill not burn out. The constant arcing in an ordinary change-over switch soon causes the metal contacts to burn and corrode. All B. & S. switch contacts are made of carbon that cannot corrode. B. & S. unique design also prevents the flash from touching any part of the switch. This switch cannot stick or bind and is positive in operation. B. & S. Ghange- overs have been used for many years in Publix, R-K-O, and other major theatre circuits. BASSON & STERN For fifteen years manufacturers of hi^h grade motion picture equipment 749 EAST 32nd STREET, BROOKLYN, N. Y. ANNOUNCEMENT . . . INTERNATIONAL PROJECTIONIST takes great pleasure in announcing the addition to its staff as Advertising Manager of Mr. James Beecroft for the past seventeen years advertis- ing manager of Exhibitors' Herald. Intimate contact over a long period of years with manufacturers and dis- tributors of motion picture equip- ment has given Mr. Beecroft a keen insight into their problems and emi- nently qualifies him to render the ut- most service to advertisers in this field. Manufacturers and distributors of equipment are cordially invited to avail themselves of Mr. Beecrof t's vast fund of information relative to the merchandising of their products. Reader interest engendered by editorial ex- cellence, no less than reader loyalty gained by editorial policy, makes the ideal advertising me- dium. That INTERNATIONAL PROJECTION- IST recognizes this fact is demonstrated by the announcement of the following list of writers who will contribute material to its columns on an exclusive basis : R. H. McCuLLOUGH Supervisor of Projecion & Electrical Equipment, Fox W^st Coast Theatres whose articles on projection theor>' and practice, based on his extensive and continuing experience as head of the technical department of one of America's largest theatre chains, are recognized as authoritative by pro- jectionists everywhere. Samuel Wein for the past twenty-five years an active research worker and authority in the electro-technical field. A. C. Schroeder prominent West Coast projectionist who combines theory with practice in a style readily understandable by the projectionist. Siegfried S. Meyers whose writings on the fundamentals of the sciences underlying the projection art have received the en- thusiastic praise of projectionists. M. ROBACH authority in the field of color photography and repro- duction who will analyze the developments in this high- ly important field. H. L. BURKITT B.S. in chemical engineering, L.L.B., and a former Assistant Examiner in the U. S. Patent Office, who will edit a patent department and contribute analyses of significant patent developments. These and many others will speak in this f omim. Occasionally we shall make room for one of those gentlemen who make a business of dealing in such terms as phi, beta, gamma, sigma, delta and the like, but not unless they explain them- selves clearly. News and views of craft develop- ments will continue, of course, to form an im- portant part of our editorial content. INTERNATIONAL PROJECTIONIST November 1931 AMPLION AMPLION OCTOPHASE GIANT DYNAMIC AIR COLUMN UNIT Weight 13 lbs. Height 5% in. Diameter 5^4 >"• Field Coil Resistance 5 ohms. Field Coil Supply 6 volts D. C. Field Current Consumption 1.2 amperes. Voice Coil impedance 1*'» ohms. Maximum Capacity 25 watts. Permanent Capacity 6 watts. Shipping Weight 21 lbs. Shipping Dimensions 12x12x12 in. This unit is also supplied with 1500 ohm field coil. Field Supply 110 volts D. C. Field Current Con- sumption 75 milliamperes. OCTOPHASE SPEAKERS OF ALL THE EQUIPMENT IN THE THEATRE THE LOUD SPEAKER IS ALL YOU HEAR Qive your amplifiers a chance It is those overtones from 5,000 to 8,000 cycles which give char- acter to speech. Can you afford to nullify your entire equipment by employing speakers which cannot reproduce these frequencies? o r AUDIBILITY - INTELLIGIBILITY - DURABILITY EFFICIENCY and FREQUENCY RANGE Choose the Amplion OCTOPHASE It is so much finer, yet costs so little more CONSTRUCTION In this unit, the area over a scientifically domed diaphragm encased in a scientifically shaped air chamber, is divided into eight divisions. The cen- ters of gravity of each of these divisions are exactly equi-distant from the throat of the unit and since all operate under identical pressures, the sound impulses from each division reach the throat of the horn in perfectly timed synchronism with the arrival of sound impulses from all the other divisions. From these eight divisions, this reproducer derives its name OCTOPHASE. (Write for folder describing the OCTOPHASE UNIT and complete line of AMPLION EXPONEN- TIAL WEATHERPROOF HORNS.) AMPLION PRODUCTS CORPORATION 38 West 21st Street New York, N. Y. AMPLION NINEFOOT THEATRE HORN JW-9 The JW-9 Horn is especially designed for theatre and indoor use. No horn of such great clarity and wide frequency range has ever been concentrated into so small a space. It covers the full speech range perfectly pre- venting over resonance and muffling on base notes. As a reproducer of music, it possesses a brilliancy impossible of attainment in horns made of soft materials. Its nine foot air column and wide bell, assure excellent performance on the low notes. List Price $95.00 Air Column 108" Bell 34" X 26" Bell Area 720 sq. inches Weight 33 lbs. Shipping Wgt. 70 lbs. Shipping Dimensions 38"x33%"x39" Angle of Spread measured at lip of bell 36° Height 42" Width 34" Depth 37" ^0^ 2s m\ ' ©CIB 135716 INTERNATIONAL PROJECTIONIST VOLUME I ■ -^ NUMBER 2 NOVEMBER 1931 SOUND PROJECTION: THEORY AND PRACTICE R. H. McCullough DIRECTOR OF PROJECTION, FOX WEST COAST THEATRES T HE projectionist of today must meet the demand for improved quality in sound reproduction. This achievement is accomplished only by periodic tests at regular intervals of vacu- um tubes, amplifiers, horns, generators, batteries, circuits and associated equip- ment. It is imperative that the output of sound projectors be matched so that the same fader setting for each projector will produce the same amount of volume output — otherwise, the difference in the output of the sound projectors will be quite perceptible to the audience. Not- withstanding the fact that the sound pro- jectors were carefully matched for the same output volume when first installed, they still require frequent testing as con- ditions may cause the volume output to drop on either projector at any time. It is true that the output volume of each projector may be the same — however, the output may include distortion. Matching Volume Output When balancing sound projectors it is important that the projector R. P.M. speed be checked first. Both projectors should be run for a while before a balancing test is made. If the projector speed is above 90 R. P. M., the higher frequencies will be accentuated. If the speed is less than 90 R. P. M. the lower frequencies will be accentuated. Therefore, the prime requisites, when balancing sound projec- tors for disc and film reproduction, are speed, quality and volume. Many projectionists rely upon the out- put of volume from the monitor horn to ascertain if both projectors are giving the same volume output. This may be considered as the "rough ear" test and will indicate within a few fader steps the matched output volume. However, this is not considered as a favorable method for first-class results. Before a check is made on sound pro- jectors for the matching of volume out- put, it is necessary to inspect each excit- ing lamp. Their filaments should be in good condition. The glass walls of the lamp in front of the lens assembly should be free from discoloration and the entire lamp should be perfectly clean. The current for each exciting lamp should be precisely the same. Occasionally veri- fy the ammeter reading of each exciting lamp. It will be found sometimes that ammeter values differ. Both exciting lamps should be properly focused. Be positively sure that the Movietone lens assembly and aperture are perfectly clean, as oil on the lens of this assembly will reduce the higher frequency re- sponse. The light gate or pressure pad tension should have the correct amount of tension against the Movietone aper- ture. The photo electric cells should be in good condition. I have found on many occasions that oil and dirt will col- lect on the window of the photo electric cell, thus preventing certain light varia- tions from being collected which will naturally reduce the volume materially. Batteries supplying potential to the photo electric cells and the plate supply for the photo electric cell pick-up ajnpli- fiers should not differ in voltage more [7] than two volts. It is necessary that the filament current for each pick-up ampli- fier be precisely the same and that each vacuum tube give the same amount of emission. The pick-up amplifier grid leak connections should be inspected. One of the greatest troubles with grid leaks is the uncertainty and the unre- liability of their resistance rating. It is imperative that grid leaks be measured for their resistance value with a meter. This can be done by your service engineer All rheostats and film-disc change-over switches should be clean and noiseless in operation, except for the usual clean "plop" as they pass from one contact to another. Many projectionists rely on the hiss from the photo electric cells for matching the output of sound projectors. If the projectionist is familiar with the results obtained from each photo electric cell, this may be considered as a fair test. When using this method, if the hiss is louder from one than from the other, further tests should be carried out so as to ascertain what is causing the difference in output. Some sound equipment manufacturers equip their faders with a rapid change- over key. It will be found very useful to use this key instead of the main knob which takes appreciable time to swing from one side to the other when making the balancing test. The best and the most accurate method for checking the balancing of sound-film projectors is to have two test films. Each projector is threaded at the same starting mark and 8 INTERNATIONAL PROJECTIONIST November 1931 started at the same time, thus checking the volume of sound first on one and then on the other. Using Test Reels It is unnecessary to have two reels of film to accomplish this purpose. All that is necessary is to have two endless loops both with the same recording, thus threaded in each projector so as to give continuous operation. The correct meth- od of making a volume balance test be- tween two sound projectors with film and disc is to have four copies of the same subject; two on film and two on disc. The projectors are then threaded and started simultaneously with both disc re- producers in position; then, whichever way the fader is thrown and whichever way the transfer switch is pushed, the same sound should come from the stage horns. A second projectionist or service engi- neer usually assists in making this test. This observer usually signals the pro- jectionist in the projection room when to change the fader from one projector to the other. Usually the projectionist re- moves the observation port glass adja- cent to the master fader and inclines his head through this port, listens, and waits for the signal from the observer in the auditorium for switching the fader key or the fader arm from the left to the right projector, or vice versa. A person with an experienced ear can always de- tect any difference in volume, or in fre- quency response. It is important that the speed of each sound projector be maintained at 90 revolutions per minute. I have found that a very useful method for ascertain- ing if both projectors are running the same speed is to place an identical mark on each turntable and, having marks in similar positions, start both projectors simultaneously. If both projectors main- tain the same speed, these marks should stay together in R. P. M. If they do not, one will creep ahead of the other, thus indicating that one projector is traveling faster than the other. The degree of similarity required in speed of sound pro- jectors is extraordinarily high. When running two projectors simultaneously in testing for R. P. M., be positively sure that both projectors are running under the same conditions-:— that is, with or without films. I would suggest that this test be made while film is being run through each projector. Crackling Noises Crackling noises may be caused by the following, which are most common with film and disc reproductions: Dirty fader contacts Dirty gain control Dirty potentiometers R. H. McCULLOUGH whose articles will appear exclusively in International PttojEciioNisT Dirty rheostat in filament circuit of speech amplifier Fuse making poor contact Loose connection Dirty switch contacts Dirty variable resistance in horn receiver control cabinet Poor connection at receiver unit Poor connection between vacu- um tube prongs and socket contacts Defective fuses Any piece of equipment, such as the fader, the gain control or potentiometer, rheostats or variable resistances and switches, require constant attention. They should be inspected and cleaned at regular intervals. These equipment troubles are inherent in all types of sound reproducing equipments. A dirty fader is the most common cause of all the aforementioned, which cause crackling noises. When fader contacts first be- come dirty, noise is first perceptible when moving the fader arm from one side of the fader to the other during the reproduction. Dirty fader contacts should be cleaned with tetrachloride: apply a very small amount of vaseline and polish contacts with a good grade of embossed paper. The first symptom of a dirty potentiom- eter or rheostat is a scratchy sound when the slider is rotated over the re- sistance wire. A dirty potentiometer or rheostat should be cleaned with tetra- chloride and the movable contacts lubri- cated by rubbing a soft lead pencil over the wire and turning the knob in order to distribute the lead evenly. I recom- mend this as a lubricant because the lead in an ordinary pencil contains a certain amount of graphite which is a very good lubricant. I have found dirty fuse con- tacts, on many occasions, which were responsible for crackling noises. This condition can be remedied by cleaning the fuse clips with fine sandpaper and then resetting fuse clips to give a tighter grip. Dirty switches are another common cause for crackling and popping noises. Switch contacts should be cleaned with tetrachloride and lubricated by applying a little vasaline. If the switch contacts are burned from arcing, it may be neces- sary to clean the contacts with very fine sandpaper. Small key switches require inspection at regular intervals. The small spring blades sometimes become bent and make a faulty contact. The contact points and blades of key switches should be cleaned with a small burnisher. Vacuum Tube Care When the vacuum tube prongs and the socket contacts have a film of corrosion over them, the grid and plate circuits are very likely to be afiFected, but the filament connections usually do not suffer from slight corrosion at these points as much as the grid and plate circuits. Dirt and corrosion on vacuum tube prongs can easily be cleaned off by means of a small nail file. The socket contacts should be given a similar treatment by holding a strip of very fine emery cloth over the ends of a spudger or any small flat stick, which permits one to clean the socket contacts without any trouble. Vacuum tube prongs and socket con- tacts should be cleaned frequently, to prevent corrosion. Vacuum tube prongs may be cleaned with a small typist's eraser. This type of an eraser consists of a small revolving piece of rubber eras- ing material at one end and a small brush at the other end. After cleaning the vacuum tube prongs with this type of an eraser the abrasions may be brushed away, thus assuring a perfectly clean contact. ELEMENTS OF THE EYE There are two parts in the perceptive elements of our eyes that function some- what differently. The part concerned with direct vision is almost microscopic in size and is made up of minute terminal filaments something like cones. With these we get the details of the objects at which we look. It is this minute area that we use in reading or in getting the clearly defined outline of a distant object. If this is destroyed all accuracy of sight is lost. It does not function continuously. It perceives quickly but the impression fades with equal rapidity so that we ac- tually see in a series of rapid flashes with intervals of about one-tenth of a second. The surrounding field of vision is that which perceives objects at which we are not directly looking, but which are at one or the other side of us. HALATION: ITS CAUSE, EFFECT AND THE REMEDY H. Parker and J. I. Crabtree RESEARCH LABORATORIES, EASTMAN KODAK COMPANY THERE has been considerable discus- sion recently on the subject of hala- tion and methods for its prevention. Halation is the blur or halo of light which is sometimes seen in photographs around the edges of bright highlights, and although it may be present through- out the area of the highlight, where it has a deleterious effect on the quality, it is usually noticed only when the blur of light extends into the dark area sur- rounding a highlight. In most cases halation is undesirable because it tends to destroy detail, and this is particularly true in the case of the motion picture because of the high de- gree of magnifipation on the screen. In order to attempt to eliminate or reduce this spreading of light around the highlights, it is necessary first to under- stand the cause. Cause of Halation When a ray of light falls on the pho- tographic emulsion, it does not. pass straight through, but is scattered in all directions by the silver bromide grains which it encounters in the sensitive layer. This scattering, which causes a spread- ing of the edges of the ray, is called "ir- radiation," and results in a slight but perceptible blurring around the edges of the image. When these scattered rays reach the back of the emulsion and pass into the film support, they are travelling in all directions, and so strike the rear surface of the support at all angles. Most of these rays pass on out into the air, but some strike the rear surface at such an angle that, because of the differ- ence in the refractive indexes of the sup- port and the air, they cannot escape but are totally reflected back into the emul- sion, thus causing a ring of light around the image. This ring of light reflected from the base is the true cause of hala- tion. The diagram of a cross-section of film shown in Figure 1, with a narrow inci- dent ray and its scattered and reflected rays, illustrates the manner of forma- tion of both these effects, the irradiation and the halation proper. Means For Solution It can be seen readily that the nature and severity of the halation will depend to a large degree on the physical charac- teristics of the negative material, because the transparency of the emulsion deter- mines the fraction of the light trans- mitted and the degree of scattering; while the tendency for reflection at the rear surface of the support will deter- mine the quantity of light reflected and the thickness of the support will deter- mine the size of the ring. Many means have been devised for re- ducing halation, either by increasing the effective opacity of the emulsion layer so that less light could reach the sup- port, or by reducing the tendency for re- flection from the rear surface. Light absorbing dyes have been in- corporated in the emulsion itself, or in a substratum over which the emulsion is coated, but this often involves an un- necessarily prolonged period of washing in order to remove the dye for printing. It was found, however, that excellent re- sults were obtained by coating the fast riegative over a slow opaque emulsion, such as a lantern slide emulsion. This acted in two ways to reduce the halation: first, because the bottom emulsion being quite opaque, only a small proportion of the light could pass through, and, sec- ondly, since it was relatively insensitive, the light which did get through to be re- flected produced very little effect. Many means have been tried to reduce the reflection from the rear surface of photographic glass plates. If some ma- terial having a refractive index equal to that of glass is coated on the back of the plate, the reflecting surface is moved to the rear surface of the coating. If then, the coating is colored with a dye or a pig- ment, such as lamp black, all the light is absorbed before it can be reflected, and halation is eliminated. Many backing materials, colored in va- rious ways, have been used with more or less success. Some of the backings were Figure 1 10 INTERNATIONAL PROJECTIONIST November 1931 FIGURE 2 Gray Base Film soluble and washed off in the developer; others contained dyes that were bleached in the developer; while others had to be removed in a separate operation after the plate had been processed. Some of these backings were quite satisfactory for practical use with plates, and came into extensive use in combination with the double-coated emulsions. A great step toward the reduction of halation was made when a thin nitrocel- lulose film was substituted for the glass plate as a support for the emulsion. Be- cause of the thinness of the film, the halation rings were so reduced in size that they appeared more as a spreading of the blur due to irradiation than as separate rings. Double-Coated Emulsions The use of double-coated emulsions on a film support practically solved the problem of halation with the non-color sensitive emulsions, but this was not quite sufficient with the improved color sensitive materials which have come into use lately. The reason for this is simple. The silver bromide emulsions absorb most of the blue light, but they pass a considerable portion of the yellow and red light. With the non-color sensitive emulsions, this did not matter, because the reflected red and yellow light had little effect on the film. But in the case of the mod- ern panchomatic emulsions, these unab- sorbed rays do tend to cause halation. With plates, cut film, or roll film, the dyed backings which are bleached or otherwise removed during processing can be used very satisfactorily, but such re- movable types of backing are not well adapted for use with motion picture film, because of the danger of offsetting dur- ing its passage through the camera, and possible contamination of the developer. With a permanent backing, however, which remains unchanged throughout the processing and handling of the negative there is no danger of chemical troubles in the developer, and if the density, or light absorbing power is properly ad- justed, it will give very substantial pro- tection against halation without being too Prints which show clearly the effect of a gray base in reducing halation Clear Base Film dense for printing. Although backings of this type have been proposed from time to time, it is only recently, with the introduction of the "Grayback" super- sensitive type of negative films, that they have been widely available to and used by the trade. Gray Base Film, The Eastman Gray Base Supersensitive Panochromatic Negative film is an ex- ample of this type. In this film, a neu- tral gray dye is incorporated in the film support in such a concentration that it absorbs approximately 37 per cent, of the incident light. This does not cause any trouble in printing, but merely re- quires an increase of one or two steps in the printer exposure. The light which causes halation, on the other hand, must travel diagonally through the film twice, as shown in Figure 1. In comparison with unbacked film, therefore, less than 37 per cent, of 67 per cent, (or under 23 per cent.), of the light producing hala- tion is reflected back into the film. In order to illustrate this effect, the Glass Plate pictures reproduced in Figure 2 were made. The object was a black mask having a series of holes illuminated from the rear. The right-hand picture was made on a plate, and shows the hala- tion rings previously mentioned. The other two pictures were made on super- sensitive panchromatic negative film& having the same emulsion, but coated in one case on a clear base and in the other on a gray base. The exposures were equal and the negatives were processed together, receiving identical treatments. The prints show very distinctly the effect of the gray base in reducing the spread- ing of light around the edges of the image. The two prints reproduced in Figure 3 show how this affects an actual picture. Although it is difficult to reproduce slight differences in quality or detail in the half-tone cut, the illustrations show that a reduction in the halation not only gives cleaner and sharper definition around the highlights, but also appar- ently increases the contrast in the neigh- borhood of the highlights. FIGURE 3 y im li a 1 :-'- r#«.-A_i5 ? ■ ■ 41 mm so ^B^Mfca f '. ;'• "immiB . tmiaimi , "tr^iism ^Itlfii ■"■' *!lh u^i'*^ urtfT 1 1 MiGIVNEf : 1^^ ■■- ft z», . ■ ■ ■ ■ ■•■;; : ?;.'■ ' *'~r S SI IM^,^«^, ■- .' V l^^l I^Sl .1 _«K> 41 Clear Base Gray Base COLOR IN MOTION PICTURES An authentic and impartial analysis of the various processes designed to impart color to motion picture film M. Robach Copyright, 1931, by James J. Finn Publishing Corp. Reproduction in whole or in part forbidden.^ FEW know the meaning of the terms "additive" and "subtractive" as used in color photography. In the additive methods generally, the positive print is colorless, the colors being produced optically and thus shown on the screen. In the subtractive meth- ods, the colors, without exception, are in the positive itself, and the finished prod- uct is ready for projection without any alteration of either the projector or its optical system. Among those companies or processes mentioned in this article there are only three which have been active within the past year or so. These are Technicolor, Kodacolor, and Multicolor. Sennett- Color is made entirely by Multicolor. The great majority of color processes have remained in the experimental or stock-selling stage, and there is no pres- ent indication that even a few will ad- vance much beyond this stage. At the present moment there is not a single color process that has even the remotest chance of displacing black-and- white pictures in the manner that sound pictures displaced the silent film. De- spite this, many enterprising persons are successfully floating many large stock issues in color companies — just by way of proving the truth of Barnum's famous remark. 1. Two-Color Subtractive Positives This is an admixture of orange-red and blue-green photographic images in micro-register which appear in the same frame of the positive, with clear white highlights or a uniform overcast of lemon-yellow tint. The negatives from which these prints are made are known as 2-color separation negatives and con- sume exactly twice as much raw stock, foot for foot, as black-and-white, irre- spective of whether these negatives are produced on a single film strip or on two separate film strips; whether successive- ly alternating or simultaneously; whether by beam-splitting prisms behind or in front of the lens or lenses; or on bi- pack (which will be discussed later) . The color values, or "separations," are ' Note. — This injunction is no reflection on our contemporaries but is a safeguard against the utilization of any statement herein by unscrupul- ous stock promoters. photographed onto the negative by inter- posing a color filter in the light beam during exposure — that is, for the "red series," an orange gelatine (No. 22-E, Wratten), and for the "green series," an emerald gelatine (No. 60-P, Wratten). When developed, the negatives appear on casual inspection to be no different than ordinary negatives. On closer ex- amination, however, the differences be- tween the red-filtered and the green-fil- tered series is easily distinguished, for wherever in the original scene were dif- ferent colors, these appear in the two series in differing densities. But where there was black, neutral grey, or white in the original scene, these appear ex- actly alike on both negatives or series of negatives. These "color values" in the negatives are transmitted to the posi- tive in the course of printing and proc- essing, and the original colors of the scenes are recreated. At least, that is the intention of the process. The lists of names which appear throughout this article refer to the per- son, company, or trade name which is identified with each particular process. Those using or manufacturing 2-color subtractive positives as part of their processes are: Brewster — Colorcraft — Colorfilm — Color- tone — Harriscolor — Ives — Jones — Kelley Du Chrome — Kodachrome (Foxcolor) — Magnacolor — Multicolor — Pathe Colora- tura— Photocolor — Sennett-Color — Tech- nicolor—Wolff-Heide. 2. Two-Color Subtractive Positives on Dupli-Tized Stock This is a sub-division of the foregoing. The two complementary red and green images are producer on obverse and re- verse surfaces of the dupli-tized positive stock, which is commonly but erroneously termed "double-coated stock." This stock costs three cents a foot ; while ordi- nary stock costs but one cent a foot. Splicing this stock is a laborious and time-consuming operation, for which rea- son exchange inspectors are not overly fond of the work. A splicer to properly handle this type of film has never been marketed. Those using dupli-tized positive stock are: Brewster — Colorcraft — Colorfilm — Har- nil riscolor — Jones — Kodachrome — Magna- color— Multicolor — Pathe Coloratura— Photocolor — Sennett-Color — Kelly Du Chrome. 3. Two-Color Subtractive Positives on Single-Coated Stock The use of ordinary stock in this proc- ess permits a saving of twenty dollars on a 1,000-foot reel, to say nothing of avoiding the splicing difficulty. This saving, however, may be nullified in pro- duction and by waste of time. The first color-in-the-film positives were made on regular positive stock, fol- lowing closely the departure of Kinema- color. By applying a second coating of emulsion to the surface of a blue-toned positive (which was first printed from the red (or orange) negative series), and exposing this second emulsion layer under the green filter negatives; then developing it and finally toning to an orange-sepia (uranium), a 2-color posi- tive was produced, the quality of which was vastly inferior to Kinemacolor. This condition obtains in all present-day sub- tractive color positives, no matter how' good they may be. If a neutral "grey key" image were to be included with the 2-color image, this lack of quality could be largely but not entirely overcome. We must certainly dub this system a 2y2-color process ; and it might possibly stave off the day when the dear public will want a 3-color proc- ess on wide film, with a quadruplex sound track to boot. Those producing single-coated color films are: Colortone — ^Ives — Technicolor —Wolff-Heide. 4. Bi-Pack Negatives A tri-pack negative consists of three separate and different color-sensi::ive films which are exposed simultaneously in contact, under pressure, in the cam- era. A bi-pack negative, or pair of nega- tives, is therefore only two films. This system is enjoying quite some favor at present, as the appended list shows. At least, it avoids the necessity for compli- cated and expensive color cameras, the regular Bell & Howell camera, with spe- cial double magazines and a slight read- justment in the gate and focusing de- 12 INTERNATIONAL PROJECTIONIST November 1931 vice, being all that is required. This is exclusive of the special negative stock used. A brief description of this process would state that an ortho (green sensi- tive), and panchromatic film is run through the camera gate at the same time, face to face, and at the moment of exposure they are pressed into contact, and thus a pair of pictures of equal size is obtained, one on each film. The ortho film has a surface coating of insoluble orange dye (matching Wratten No. 23-A). Now, during the exposure, the ortho film records the blue and the green col- ored areas of the scene (along with many other things), and the reds and the oranges are omitted, this film being insensitive to these colors. The red and the orange elements of the scene pass through the emulsion and then through the orange filter coating, which does not pass the blue and the green rays, and thus onto the panchromatic film, which records everything except the blues and the greens. The "front" (ortho), film will now contain values representing the blues and the greens, in addition to the regu- lar black-and-white picture structure; and the "rear" (panchromatic), film would contain the complementary values, i.e., orange and red, together with the black-and-white picture. Incidentally, yellow is recorded on both films equally- and is reproduced as white. The devel- oping time can be so adjusted that both negatives have practically the same con- trast, which is a most desirable condition in color negatives. This is not so easily obtained in single strip negatives. Those using bi-pack are: Colorcraft — Colorfilm — Ives — Kelley-Uu- Chrome — Magnachrome — Pathe Col- oratura— Sennett - Color — Magnacolor — Muhicolor. 5. Single Strip Two-Color Nega- tives Kinemacolor was the first to utilize this method, the images being exposed in uniform succession. The frequency was 32 per second, or so it was claimed, and upon projection this rate was increased to 40 per second. If the rate had not been increased, the flicker would have rendered the process valueless. Where there was fast action, the outlines of the moving object displayed upon projection "fringes" of pure prismatic color. A later refinement (probably origi- nated by Claude H. Friese-Green), was to expose in unequal succession, in hop- skip-and-jump fashion, so to speak; 1-2, 3-4, 5-6, etc., illustrates the idea. The "fringing" was thus reduced to such an extent that it became negligible. Technicolor exposes simultaneously, using beam-splitting prisms, and there is not the slightest "fringing" possible in this process. One of the series of sep- aration negative images is right-side up, and the other series in inverted — these two series alternating in succession on one film running vertically as usual. Those using single strip twolcolor negatives are: Colortone — Jones — Kodachrome — Photo- color — Technicolor. 6. Printing From Master Positive, Instead of From Original Negative Kodachrome. 7. Color in the Negative Direct Wolffe-Heide. The underlying principle here is the same as in the bi-pack method, but the two emulsions are carried on one surface Visitron Photoelectric Cells Table of standard Visitron photoelectric cells, showing the essential characteristics and the makes of sound equipment using each size Standard Visitron P.E. Cells Height, not Including Prongs Style of Base Bulb Diameter Maximum Voltage Sound-on-Film Equipment in Which the Various Standard Visitrons may be Used. (List subject to correction.) 53-AWB 2M" no base 'A" 90 vclts Ficphce; De Forest (Gen'l Talk. Tic); Kinoplay; and Tobis. 58-AWB k" no base Vs" 90 vclts ■ Auriphore; Au itone; Duo-Fone* (old equip.); T'lec-Tro-Fone; Monarch*; Fhototone* (old equip.); Rapid Film; Sonofilm*; Syn- crofilm (Weber). 58-A 2H" small UX Vs" 90 volts Brinner "Perfectone"; Duo-Fone* (new equip.); Kinetophone; Ruby Portable; Synchrofone (Stamper). 59-A 3^2" small UX 1" 90 volts RCA; Vocaphone. 71-A 2"^2" standard UX IK2" 90 volts Belotone; Bestone* (new equip.); Cinevox; DeVry Portable; Doo- leyphone; Motiograph (Enterprise); Fox Electric; Masterphone; Goodall*; Homes, Indianapolis Sound Equip.; Kautz "Perfectone"; Lincrophone; Mellaphone; Pacent; Pictur-Fone; Phototone* (new equip.); Preddey*; Royaltone; Royal Amplitone*; Saf-Ray (Simp- limus); Douglas (Slipper); Talkiephone; Universal*; Wonder- phone; Moviephone; Tone-O-Graph*. 73-A 2K" standard UX I'Mi" 90 volts Preddey*. 75-A Z'Hi" standard UX IH" 90 volts Carter "Dramaphone." 79-A 4M" Special prongless base with leads SKe" 90 volts Preddey*; Ultraphone; Western Electric. [This table, prepared exclusively for International Projectionist] * Asterisks show that the equipment indicated has more than one model, one model of which can use the cell indicated. There aie also 8 special Visitrons designed particularly for use in equipments not listed above. For further information apply direct to G-M Laboratories, Inc., 1735 Belmont Ave., Chicago, mentioning this publication. November 1931 INTERNATIONAL PROJECTIONIST 13 of the negative, in two separately ap- plied layers. Raw stock is specially made for this purpose by Afga. The old panchromatic cine negative stock made by Eastman, prior to their "Type 2," was of this type, although not intended for coloring after development. This com- pany's commercial panchromatic film (for stills), was, and probably continues to be, made with an ortho (green sensi- tive), layer, and a red sensitive layer. With both layers naturally being sensi- tive to blue, the film takes all visible colors. We can take a negative of this type, after the final washing, and transform it to a two-colored negative by "double- toning." The top layer would be con- verted to a common blue tone (not a tint), and the bottom layer next to the celluloid could be toned uranium (orange). The positives are made on the same kind of stock, but of slower speed, and the coloring is carried out in the same manner as in the negative. The cameras and printers are the same as in black and white, without alteration. 8. Chemically Produced Colors, With or {Principally) , Without Ad- dition- of Mordanted Dye Colorfilm — Harriscolor — Jones — Magnacolor — Multicolor — Pathe Coloratura — Sennett-Color — ^Wolff-Heide. 9. Mordanted Dye-Tones {Silver Iodide Mordant) Brewster — Colorcraft — Photocolor. 10. Combination of Chemical {Blue) Tones and Dye-Tones Colortone — Ives. 11. Images in Pure Dye Only Kodachrome — Technicolor. 12. Hydrotype Positives Technicolor. In this method the printing is effected by a photographically produced "relief matrix" charged with water-soluble ani- line dyes, contacted for some minutes with a damp blank film coated with clear hardened gelatine. The contacting, or printing, is performed on an endless steel belt with special sprocket teeth along the two edges, this being necessary in order to register accurately the two succeeding impressions. There are, of course, two matrices for each finished print. These matrices are recharged with dye after each printing, and thus a number of prints can be made from the same matrix. The printing does not require the usual "dark-room" pre- cautions, it being carried out under white light. As this particular printer is well WILLIAM F. CANAVAN SAYS: IT is true, of course, that an able projectionist mu^t be a good mechanic, but it does not naturally follow that a good mechanic would be an able projectionist. My impression of the matter is that real showmanship is one of the most essential qualities for the real projec- tionist. He must be show-minded in all that the term implies, with a background of theatrical experience which will imbue him with that inherent theatrical spirit, — ^'The Show Must Go On,' no matter what may happen. No amount of academic training could possibly produce an outstanding projectionist. The essentials for good projection ar« not to be learned out of books alone. True, the theoretic approach will be of value to the novice and will be highly beneficial to the expert* enced projectionist; no man ever lived who knew as much as be ought to know. When any man reaches a point where he imagines he has all the knowledge he should have, it is a certain indication of his need of it. patented, no one has yet attempted to copy it. The late Max Handschiegl was the first to use this principle, utilizing a circular drum arrangement for contacting and registration. In the silent picture '"Wings" the flame effects of the falling airplanes were done by the Handschiegl process, sometimes called "spot coloring." Subsequently, another attempted to make prints (21/2-color), by using the Hand- schiegl machinery, but did not have much 13. Keller-Dorian Process Kodacolor — Kislyn — Paramount- Publix— Liquid Air Corp. (N.Y.). A scientific term for this process would be "3-color additive lenticulated film." As the Kodacolor process has been ex- plained in detail on many occasions, we need not go into detail on it here. The method was invented and patented by Albert Keller-Dorian in France. Well- informed technical opinion does not hold this process to have much chance of suc- cess on 35 mm. film. 14. Three-Color Additive Simul- taneous Projection Chronochrome, Gaumont — Feather- stone — Opticolor — and all forms of the Keller-Dorian process (which see). Chronochrome is owned by Eastman Kodak Co. The colors are almost a per- fect match of the original scene which, of course, cannot be said of 2-color sub- tractive positives. It requires a special camera with three lenses, a special pro- jector with three lenses, and an extra assistant near the screen to register the three simultaneously projected images by remote control. In all of these processes the shrink- age of the film, both in negative and posi- tive prints, is one of the greatest obstacles to success. 15. Three-Color Linear Mosaic Film, Warner-Powrie. In this process the colors, while addi- tively produced, appear in the negatives direct, in the printed positives, or in the "direct positives." A remarkable feature of this process is the high degree of uni- formity of colors obtained, there being no visible fluctuation. About twenty-five years have been spent in an attempt to develop this process which, while simple in principle, has proven difiicult to put on a manufacturing basis. It can be used for newsreel work, as the positives can be printed from bi-pack (resulting in 2-color) and processed exactly the same and as fast as black-and-white. It is intended, however, that this process will find its first application in 16 mm. photography. 16. Four-Color Simultaneous Addi- tive Projection Cox Multi-Color. 17. Intended for Wide Film Magnachrome (2-color successive addi- tive with alternate dyed frames). 18. Wide Film Masking Propor- tions Chronochrome, Gaumont (35 mm. with frames three perforations high). 19. For 16 mm. Kodacolor — Warner - Powrie — Vita- color. 20. Sound Track Inconvenient or Impractical Keller-Dorian — Kodachrome — Warner- Powrie. {This is the first of a series of articles on color photography and projection. Color film projec- tion will be discussed by Mr. Robach in an early issue. — Editor.] EVOLUTION OF THE I. A. BULLETIN R. O. Baker SECRETARY-TREASURER, L. U. 269, LAWRENCE, KANSAS 'General BuUetm No. 266 luucd from the Generel Offices of the INTERNATIONAL ALUANCE OF THEATRICAL STAGE EMPLOYES AND MOVING PICTURE f MACHINE OPERATORS OF THE UNITED STATES AND CANADA SbIU 200S, 1460 Brondwar, Naw York, N. Y. TueMUy, SepL 1, 1931 f.'J,."?,'!," i^Vynne* v^ ,.j„,.™u™ ......v.Ardniore.'^Pa.; JOSEPH C 1,. WILLIAM T, MADIGAN. SIXIN Vice-Prisid r^JO^N'MeCARBOt.L.'' ' "" ' ""' '^"'^ ' " IMPORTANT NOTICE— Thi» Bdlletin must be read at the next specEal of your local union and permanently filed with its records. regular meeting NEW COLUMBIA BURLESQUE CIRCUIT i. playiDg the New Columbia Burlesqua CHARTER REVOCATIONS leel t: Car tor placing n In whose Reproduction of the front page of the General Bul- letin, official or- gan of the Inter- national Alliance, as it appears to- day • and Properlyman. The such traveling inembors Is that the jurisdiction BueJi attraction opens ine eeaK both traveling-.' mechanics. The Inetructloa each ol the locfil.unloDB provides that one ot the travelln); pien ahali be a member ol the local unlon-ln whose Juris- diction such attraction p lays 1 is opening eneDgemeDt. Tho second travel nig "member shall b« a member ol some local union Id wbo^ Jurisdiction no burlesque attraction will be opened. Thlh Is done (or the purpose ol seelnc that there Is no d J ?c rite I nation iji tho matter. b^vcry Ideal unU)n-[>laclne Iraveliag.QiecbiinlcB'wltb one of the burleBdue nltractions 'is required to noilCy (he Gen- iral OfTlce Immediately. ol tbc name of each of tbe members [ilaced, as well as Information concerning the local union -^^"--. Ilti n "^""^ President Hart s sug- presented by the Cincinnati Local calling locals asserted their votes had been in ^^^ ^°^' for adoption of the Cummings plan ; correctly counted." FLOYD M.BILLINCSLEV CHOSEN AS SEVENTH VrCE-PRESIDENT IiKernnnonal Preaident Wllltnm F. Canovan has selccied Brother Floyd M. BUIIagaley, Rualncus Representative of Sao FranclECO. Collf^ Operators' Local UtUon No. 162. to till the vacancy existing In the office ot Seventh Vlce-Preat. lient. which was created by the rcslEoatlon of former Vice. President Cleve Beck. This appolatment met with the unanimouB approval of the General Executive Board and cnnflrmed the previous report that the selection would be SOUTHERN LOCALS CO-OPERATE. 16th coofercncs was held hi Executive Board'inembera of Atlanta, G^i., Local No. H^S; BInnlusbain, Ala., L.ocal No; 236: Chattanooga. Tenn.. Local No, ^59; Knoivllle. Teim„ Local No. 405. and Nashville. Tenn., I.ocal No. 626, In at- tendance. Representative William P. Raoul acilog Os Ih'*. presiding officer. This meeting was devoted to the discus- sion and exchange at latormation regarding the negotiation of new contracts. After hearing an eipoeltiorx'ot the con- troversy now existing In Blrntlngbam, where ten theatres have'beeu closed because of. the rcfnsal of the'Opcrators to agree to -terms laid down by the managemonta, such- terms being demanded In tbe face of signed af^rOements, the attending locale voluntarily agreed to levy a'^eekly aroent on their working members to asjlat the Blrmlng- local otganlzatlOQ In Its fight. for a referendum vote." A year later, Mr. Hart presented the results to the delegates: the vote stood 1,399 for a journal and 4^2 against, although several The First "Journal' S. E. It is At the sanae Convention (1895), how- moreover, a second resolution was pre- "Sl.r '■^^°^"^^°" ^^\Pr.e^ented for a sented by the Toledo Local calling for f, " H or journal to be issued not less the adoption of the Toledo Union as the The first issue of the /. A. T to be the offici V"'' ^ rr Iir '"^ '''^'^^^ "'^^"- '^^^'^ resolutions were Journal was dated April, 1910. Tli,-c ^ *i t^'^ organ of the Alliance . considered simultaneously. After consid- certain that at least four issues were poned. "^^^ indefinitely post- erable discussion, the delegates adopted published-April, May, June, and July. (unanimously, according to the conven- Although the convention proceedings* tion proceedings), the motion of Dele- would lead one to believe that the Jour- gate Kelly to make the Toledo Union the nal was also published in August and in the librarian of Johns 1895 Membership Small It is interesting to speculate upon the reasons for the adverse vote. Financial *^*^*^^ P^P^""- ^^^^ ^^^ion automatically September, 1910, tl difficuhies and the small membership ^'^P°^^^ ^^ the Cummings' proposal.' Hopkins University says the library probably were chiefly responsible. Per ^^ ^^^ annual convention in Omaha records show only the first four issues capita tax was at this time only 20 cents ^^^ following year the delegates voted named above. Thus, the Journal was a year; and the total membership of the "^^ rescind the action of the preceding published for only a short time and then I. A. surely did not exceed 2,300. (The convention. Instead of the Toledo Union suspended. No reason for the suspen- financial statement shows that per capita ^^^ delegates selected the Illustrated sion, or the date thereof, can be found was paid to the American Federation of ^^'"^^ ^^ ^^^ official organ.* Just how i" the printed proceedings; and, al- Labor on only 2,000 members.) The long the latter remained the official paper though it is customary for publications total receipts reported at the 1895 Con- '^ ^^^ shown by the convention proceed- ings. Again at the 1907 Convention a resolu- tion was introduced which sought to have the Alliance publish its own official vention were less than $700. Two years later (1897), a letter from W. F. Cummings, Secretary of Cincin- nati Local No. 5, was read to the con to announce any suspension in their con- cluding numbers, nothing of the kind was done in the Journal. In the ab- sence of definite information, it is rea- sonable to suppose that financial diffi- vention. Mr. Cummings suggested pub- journal; but definite action looking to- culties may have caused the suspension lishing a weekly paper, the size of which ward publication of an organ was de- was to be 27 in. x 38 in., 5 columns, ferred until "such future time as ways 8 pages. He thought that it should be and means can be found . . .'" And at named "The Grip." According to his the 1908 Convention, Mr. Hart, who was plan, each local would be entitled to 85 then Secretary-Treasurer, presented fig- yearly subscriptions and six inches of ures to show the cost of publishing a advertising each week. In return, each trade journal. By order of the Conven- local union was to pay $10 monthly in tion the question of establishing an offi- During the administration of Charles C. Shay, the Journal was reestablished by order of the 1915 Convention." Monthly publication was commenced in October, 1915, and continued until June, 1920, when the present General Bulletin was established. Financial troubles did not cause the advance. The plan, if adopted, was to go cial journal was sent to the local unions demise of the Journal in 1920, (only, in- [14] November 1931 INTERNATIONAL PROJECTIONIST 15 sofar as many members objected to the 5 cents charge made for this purpose), since there was a balance of more than $10,000 in the Journal Fund on this date/" But Secretary-Treasurer Lemas- ter, at the 1919 Convention, had spoken of the lack of cooperation being re- ceived from local unions and from in- dividual members in furnishing news items and their correct addresses for de- livery of the Journal."- This may have a motivating factor in the suspension. The "General Bulletin" For three and one-half years the Gen- erl Bulletin was issued weekly. On January 1, 1924, it was made semi- monthly." President William F. Cana- van explained this change was due to the heavy financial burden of weekly publication and also because "the news was not of direct nature." This, he added, was contrary to the purpose of publication.''' Semi-monthly publication was con- tinued until May 6, 1925, when the In- ternational officers decided to issue the General Bulletin but once a month. The announcement of this change stated that "inasmuch as the majority of the local unions hold their meetings once a month, it is believed this policy will best serve the interests of all concerned'"*. It was also intimated that the money saved on the printing of the extra issue each month could be used elsewhere to good advantage. The General Bulletin continues today as a monthly publication. REFERENCES: [Note: The following references, but one, re- fer to the Combined Convention Proceed- ings.— Ed.'\ 'Page 18 (1895 Convention); ^ page 23 (1895 Convention); "pages 43, 45—47 (1897); * page 62 (1898); 'page 253 (1907). "Page 266 (1908); 'page 316 (1909); « page 375 (1910); "page 356 (1915); and pages 599 and 609 (1917). '"Page 747 (1922); "page 680 (1919); 785 and 805 (1924); "pages 785 and 805 (1924); "General Bulletin No. 191, April 21, 1925. Recurrent Reproducer Noise THE sources of noise of an intermit- tent or recurrent nature are usually much more difficult to locate than are the causes of steady noises. The very fact that such noises come and go inter- mittently makes it difficult to know when the cause has been located. Pre- ventive measures are therefore much more effective in dealing with such noises than are remedial measures. The causes of intermittent noises are briefly: Batteries — run down, loose con- nections ; fuses — corroded, dirty clip con- tacts; charging panels — loose connec- tions; amplifiers — loose connections; poor tube contacts; faders — dirty con- tacts; motor generators — brushes, com- mutators; motor generator filters — loose connections. Noisy "B" Batteries As B-batteries (dry type), deteriorate, they tend to become noisy and should, therefore, be replaced when the voltage drops below the proper figure. This is especially true of the "C," or grid, batteries, which are used in some of the earlier type amplifiers. Spring ter- minals on these batteries should be kept clean and care taken to make certain that firm contact is maintained with the spring terminals inside the battery boxes. Charging Batteries The tops of storage batteries must be kept clean and dry. They should oc- casionally be wiped off with a cloth moistened with either a solution of bicar- bonate of soda or ammonia. The con- nections should be kept tight and prop- erly protected from acid fumes by the use of non-oxide grease. It is well to remember that imme- diately after batteries have been charged, gases will still be forming in the elec- trolyte. These cause slight variations in the internal resistance of the battery, re- sulting in noise being introduced through the amplifiers. Batteries should there- fore be taken off charge at least 30 min- utes before the sound system is needed. Fuses sometimes become corroded in- ternally, and frequently dirt collects or corrosion occurs at the ends where they fit into the clips. Either of these condi- tions may result in noise. This is espe- cially true of the battery fuses in the 90-volt photo electric cell and film ampli- fier circuits. Connections and knife-switch contacts should be checked occasionally to reduce the possibility of noise from loose con- nections and poor contacts. At the time of installation, all connections are made secure. Subsequently, however, vibra- tion may cause these connections to work loose, with the resulting possibility of noise. The switch-blade contacts on the battery charging panel should be kept clean and bright by occasional cleaning with fine sandpaper. Vacuum Tubes Amplifiers, especially the first stages following the photo electric cell or disc pick-up, are very sensitive, and inspec- tion of them at periodic intervals of, say, one month, is good insurance. Vacuum tubes should be removed in order to clean the contacts on the ends of the prongs and the spring contacts of the tube sockets. The eraser on an ordinary lead pencil is excellent for this purpose, but care is necessary to insure that none of the rubber particles remain on the contacts after cleaning. A file or sandpaper must not be used. The spring pressure should be noted when the tube is replaced. Appreciable pressure is necessary to insure good contact, and if this pressure is lacking, the contact springs of the socket should be bent up to increase the pressure. All power should be turned off while work of this nature is done, in order to prevent shocks or damage to the equip- ment. Grid leak contacts should be cleaned, and spring contacts should hold the grid leak firmly in place to prevent noise due to poor contacts. P. E. C. Amplifiers The photo electric cell amplifier is sus- pended in a crade by coiled springs so that it is free to swing without touching the metal amplifier housing. An occa- sional inspection is advisable to make sure the amplifier is swinging freely and the springs have not become stretched. It is essential that the anode block associated with the photo electric cell be securely fastened down and that the anode lead from the cell has sufficient slack to prevent the transmission of vi- bration. The amplifier wiring should be inspected for signs of loose connections. If they exist, loose connections are quite likely to result in intermittent noises, the causes of which may prove to be excep- tionally puzzling. Rheostats, potentiometers and keys should have their contacts cleaned oc- casionally. The time so spent will "be well worth while in preventing noise from these sources. Fader Contacts Fader contacts will give little trouble if they are cleaned occasionally with chemically pure carbon tetrachloride. Ordinary carbon tetrachloride should not be used for this purpose. After cleaning the contacts with tetrachloride, a thin coating of vaseline should be applied and the excess wiped off. If a motor generator set is used for filament or plate voltage supply, it is ad- visable to make weekly check inspections of the condition of the brushes and com- mutator. If it is equipped with a filter, the connecting straps should be checked to make sure they are tight. Particles of dust or dirt may occasion- ally lodge in the light gate and cause noise if they move due to the machine vibration. Ordinary care in routine cleaning will prevent trouble from this NEW 3x4 STANDARD APERTURE FOR PROJECTION THEATRE screens will be a stand- ard shape for the first time since sound pictures were introduced, if a proposal favored by a majority of Hol- lywood studios is adopted by both the studios and the theatres. Improved photographic effects and more eiScient use of the image space on the film are expected to result. The height of all screens will be three-fourths the width, a proportion first established by Edison in 1889 and used until three years ago when the sound track was put at the side of the film and the picture consequently became more nearly square. A majority of the studios have ratified standardizing specifications drawn up by the Academy of Motion Picture Arts and Sciences. Theatre practices are now being surveyed, and if the change is found to be practical for a majority of theatres, pictures photographed accord- ing to the new dimensions will probably be ready for release by the first of the year (1932). In the meantime, all the- atres will be given detailed data from which to make the comparatively slight and inexpensive changes in projector apertures and screen masks which will be necessary to bring about uniformity. Leading Studios Approve Studios which have notified the Acad- emy to date that they are in favor of making the proposed change include: Educational, Fox. Hal Roach, Metro- a (ZL Goldwyn - Mayer, Paramount - Publix, RKO-Pathe, RKO-Radio, United Artists, Universal, and Warner Brothers-First National. The establishment of uniform 3x4 proportions for theatre screens is ex- pected to settle a production difficutly which has vexed studios and theatres since the sound track method of record- ing was introduced. The studios have had to photograph actors and scenery so that the picture could be shown on an oblong screen in some theatres and on a virtually square screen in others, de- pending on the method of sound record- ing used and other mechanical factors. This has frequently resulted in part of the top, bottom or sides of the picture image being cut off the screen. The picture image will be photo- graphed on the film in 3 x 4 proportions as it is to appear on the screen. The sound track will be left on the film as at present, but the frame lines between the picture image will be made wider. Ex- tensive research and study were neces- sary to secure the exact specifications for the new standard as allowances had to be made for progressive shrinkage in the film stock and the accuracy of registra- tion in cameras, printers and projectors. It was found possible to use the space on the 35 mm. film more effectively than when sound pictures were first intro- duced, and the new standard will per- mit the studios to use four per cent, more area for dramatic action than was possi- ble while variation in theatre screen shapes had to be provided for. The camera aperture proposed is .651 inch by .868 inch, allowing for a the- atre projector aperture of .615 inch by .820 inch. Basis for Standardization This is the second step in the stand- ardization of apertures begun by the Academy in 1929. It is made possible now by the decrease in the use of sound- on-disc and the increasing number of theatres which use a reduced 3x4 pro- portional aperture. The original Academy specifications were made to take care of an emergency situation. A large number of theatres using sound-on-film had given up the nearly square Movietone screen shape for mechanical and other reasons and were insisting on using a reduced aper- ture in 3 x 4 proportion. Consequently the heads and feet of characters were being cut off. since the studios at that 74-4 5 : i D I I FIG. 2. PROJECTOR APERTURE The projector aperture dimensions have been stated on the basis of projeciion^on^the-level, as no uniform provision for the keystone effect can be made. The calculations have been carried out with due regard to the fact that in projectors the film is controlled at the right-hand edge FIG 1. CAMERA APERTURE The dimensions indicated provide the maximum aperture which will leave an adequate margin of safety. It should be emphasized, however, that laboratories should print both picture and sound track with the greatest possible accuracy. In the dratving the center line of the right hand side sprocket holes is used as the base center line for calculting all dimen- sions, since cameras and printers register at this point [16] November 1931 INTERNATIONAL PROJECTIONIST 17 time were photographing for the full height of the frame. The Academy made a national survey of the situation (the results of which are given in Table A), and found that some- thing had to be done — although there was still so much full-frame disc release that it was too early to standardize. As a temporary measure the Academy then recommended that all vital action be kept within a 3 X 4 rectangle marked on the camera glasses of such size that the pic- ture would not suffer when projected through a reduced proportional aperture. For the past year cameramen have thus had to fill about twenty per cent, of their frame — the ten per cent, of sound track area, five per cent, at the top, and five per cent at the bottom — with non-vital action or unessential views of the set. Re-Centering Methods Probably the most difficult problem in connection with the reduced aper- ture method {A in Table A), is to re- center the picture after it has been en- larged. The amount masked out from the top and bottom of the picture in re- ducing the aperture is calculated to bal- ance the increased magnification so that from the standpoint of height the pic- ture will fit into the screen frame. Magnification extends the left margin of the picture to cover about half of the blank strip. The right margin is ex- tended an equal amount beyond the black border so that the picture must be moved to the left in order to be properly centered. Several other aspects of the reduced aperture practice are worthy of notice herein, as follows: 1. The shorter focal-length length in- creases the graininess of the picture on the screen. No theatre reported this as a serious defect. 2. One theatre chain called attention to the fact that the smaller aperture slightly reduces the amount of light that gets to the screen. Due to the fact that the size of the picture is increased, this reduced light must cover a larger screen area. However, there has been no indi- cation that this constitutes a serious problem. The Framing Problem 3. The projectionist's problem of keep- ing his picture in the frame is more dif- ficult and requires painstaking care. Al- though the cameraman may keep his ac- tion within the smaller area he usually fills up the balance of the frame with foreground and background for the bene- fit of theatres using the standard aper- ture. This means that the projectionist finds no indication on the picture as to the exact line of its upper and lower limits. More is dependent upon his own judgment than formerly and his respon- sibilities are greater. The proposal now is to mat off this useless space in the camera and stand- ardize the American industry on the 3x4 proportions preferred by the theatres. By careful calculations it has been found possible to use a little more image area on the film than has been included in- side the marks on the ground glass and thus give four per cent, more image area for vital dramatic action to reach the screen.* The proposed standard aper- tures for all pictures are: * Note.— -The question of the relation of the motion picture aperture to a possible aperture for television was brought to the attention of the sub- committee by the Television Committee of the Radio Manufacturers Association. The standard specifications allow for an adaptation to the re- quirements of television when such adaptation may be commercially desirable. New Camera Aperture: .651" x .868" {Corners to be rounded by an arc of a circle of .0279" radius) Replacing the present: Ground glass markings of: .620" x .835" in the Mitchell aperture of: .720" x .923" and the Bell & Howell aperture of: .720" x .969" New Projector Aperture: .615" x .820" Replacing the present: Most commonly used proportional of: .600" X .800" Movietone aperture of: .680" x .800" Old silent aperture of: .680" x .906" (Continued on next page) Table A. Summary on Theater Aperture Practices Theater Chain Projector Aperture Policy for Projector Aperture Dimensions for Sound-on-Film Pictures Sound-on-Filra Picture* Publix Theaters, Inc. Method A standard for all larger houses 0.593" X 0.796" Loews, Inc. Method A standard for all larger houses 0.607" X 0 800" Fox-West Coast Method A standard for all houses. About 65 houses already installed 0.597" X 0.796" Fox-New Englana Method B in all houses; if no better improvement by fall, 0.680" X 0.820" (approxir will adopt Method A mate) Balaban and I^tz Method A standard for circuit 0.609" X 0.815" Warner, Brothers-Skouras Bros. Method B in all theaters 0.680" X 0.820" (approxi- Ci;:ciiit mate) S^e'nger Theaters Method A standard for circuit for Silent and Vitaphone as 0.610" X 0.829" well as sound-on-film Universal Theaters Methods B, C, and D 0.680" X 0.820" mate) (approxi- Commertord Theaters Method A standard for circuit 0.600" X 0.810" R. B. R. Amusement Company Methods B, C, and D R. & R. Circuit Methods B, C, and D R. C. A. equipped theaters. Method B standard for all (R-K-0, etc.) houses 0.687" X 0.812" Method A in not more than 5% 0.624" X 0.812" *S.M.P.E. standard projection aperture — 0.680" x 0.906". When sound track only is masked out the aperture is reduced to approximately 0.680" X 0.820". Simplex standard apertures — Vitaphone or silent picture. 0.679" x 0.904". —Movietone picture, 0.6093" x 0.7968". Method A — Combination of Reduced Aperture with Shorter Focal Length Lens. — An aperture is inserted in the film gate which masks out, in addition to the sound track, a portion from the lop and bottom of the picture sufficient to reduce the height to about three-fourths of the reduced width. The smaller 3 by 4 picture is enlarged by a one-half inch shorter focal length lens to fill the screen. Recentering is accomplished by aux- iliary devices which enable the lens on the ma- chine 0 be moved from right to left. Unless due allowance has been made in production for this smaller aperture vital portions of the picture will almost certainly be cut out. The estimated cost of installing this method is $200. Method B — Movable Mask or Flipper. — A mov- able mask or flipper about 30 inches wide at the left si;'e and facing the screen changes the screen shape to correspond with the picture shape. When sound-on-film pictures are being shown it i? moved over to cover the blank strip on the left of the screen. The flipper is operated by a stage hand, some member of the regular house staff, or by remote control from the booth. Method C — Blank Strip on the Left Side of Picture. — A sliding plate masks out the sound track. A blank strip shows on one side of the screen. Method D — Small Blank Strip on Each Side of the Picture. — Rather than leave a blank strip on the left side of the picture some theatres shift the projection mach'.ne in order to center the pcture, so as to divide the blank area between the two sides. 18 INTERNATIONAL PROJECTIONIST November 1931 Specifications for the standard aper- tures as worked out by the subcommittee in consultation with studio and equip- ment company technical representatives are shown in the accompanying illus- trations (Fig. 1 to 4). Some of the fac- tors and conditions considered are given in the following analysis by J. A. Dubray of the subcommittee: 1. For Negative Films a. The plus and minus camera tolerances which include the location of the aperture (construc- tional tolerances) ; the size of the aperture (con- structional tolerances) ; and the side weave of the film on the register teeth of the intermittent mechanism. b. The plus and minus tolerances which must be allowed in accumulating the camera toler- ances with a 54% film shrinkage. 2. For Positive Films c. The plus and minus tolerance required in printing a positive and calculated first from the effect of registering the positive film against the right-hand side of the teeth of the main printer sprocket while the negative registers against the left-hand side; second, from the effect of regis- tering the positive and the negative films in the opposite direction. Both cases for unshrunk posi- tive and accumulating with the tolerances ar- rived at (b). d. The plus and minus tolerances calculated from the (c) tolerances plus a positive film shrinkage of H%. e. The plus and minus tolerances calculated from the (c) tolerances but with the addition of a positive film shrinkage of 1K%. The results obtained from the above have been derived with the assumption that the negative has only shrunk i/2%. However, since the shrinkage effect con- stantly progresses , through the printing process as well as while the films are stored away, the calculations have been extended to include a greater negative shrinkage. The following series of computations was carried out, accumulating the plus and minus camera tolerances, with the tolerances necessitated by the various conditions expressed above, with the ex- ception that a maximum 1%% shrinkage of the negative was considered instead of the minimum %%. 3. For Negative Films a'. Camera tolerances same as for (a). t .24-3 a CD o CD CD CD CD SotfWO Tt-XCK. .104- MiM. .ooVMtw. o CD CD O CD a CD CD O ^ .oso'Mna. ^ .lOQ-WHN- FIG. 3. SOUND TRACK ■ This drawing is a detail from Figure 1 to show the minimum requirements for sound track width and location b'. Tolerances resulting from accumulation of (a') and VAVo negative shrinkage. 4. For Positive Films c'. Tolerances required in printing with un- shrunk positive for both conditions of film regis- tration expressed at (c), but accumulating toler- ances calculated at (b')- d'. Tolerances calculated through the accumu- lation of tolerances at (c') and H% shrunk posi- tive film. e'. Tolerances calculated through the accumu- lation of tolerances (c') and 'A % shrunk posi- tive film. The latest being the extreme case, ac- cumulating a maximum permissible shrinkage and all constructional and reg- ister tolerances taken from the camera, the registering tooth, the processing of both positive and negative and those of the printing of the positive film, which are due to the differences in shape and dimensions of the positive and the nega- tive perforations. The above method of determining shrinkage and mechanical tolerances has resulted in the determination of a maxi- mum camera aperture as illustrated in Fig. 1. Taking the above dimensions and com- puting according to the accumulated tol- erances determined at (d), (e), (d') and (e'), the maximum and minimum di- mensions of sound track and picture area of positive film are derived as shown in Fig. 4. Advantages to Studio 1. Economies. — Cinematographers esti- mate that from a half-hour to an hour a day now spent in setting up for composi- tion in three apertures — full frame. Movietone frame, and proportional — can be saved or devoted to improved photog- raphy. Scaffold lights can be lowered from three to five feet, thus making pos- sible a reduction in the wattage or num- ber of units. The tops of large sets can be lowered by as much as six feet, and all sets can be reduced in width by nearly ten per cent, without making any change in the placing of essential action and props as photographed for the past year. 2. Improved Quality. — A single aper- ture will make for better composition on the set for both the cinematographer and the director. The studios will be as- sured that the picture will be projected as it was photographed. Projectionists have had wide leeway in framing and no guide to show them when their propor- tional aperture was centered until they saw heads or feet cut off on the screen. Microphones can be lowered from three to five feet, resulting in an obvious advantage in sound quality and conve- nience for the sound department. Cam- era lenses can be re-centered on the new aperture for better optical coverage. Advantages in Theatre 1. All pictures can be projected through a single standard aperture, doing away with movable flippers and changes of screen masks, aperture plates and lenses during the show. 2. The frame lines just outside the aperture as they used to be for silent pic- I .^lo'C-fclCINKL .&0 vsr .^9?6fe" .lo9 0»ICIW»>. ■I»7»* .IO&6S" FIG. 4. MINIMUM AND MAXIMUM SOUND AjND PICTURE AREAS This drawing is a composite view of the dimensions resultant from the calculation of shrinkage and mechanical tolerances from which Figure 1 was derived November 1931 INTERNATIONAL PROJECTIONIST 19 tures will be a help to the projectionists in keeping in correct frame. If the pic- ture should momentarily go a little out of frame the projectionist will be warned by seeing a frame line, but as the lines are wide, the mis-frame can be corrected before the audience notices it. 3. Standardization of exact dimensions by the studios will give the projectionist more uniform prints from the various companies. 4. Theatres now using reduced propor- tional apertures will gain four per cent, more screen image without additional magnification. 5. Theatres now using the Movietone aperture or the old silent aperture will gain the advantage that the studios can fill the whole area of the new standard aperture with essential dramatic action and will not have to leave a border of un- important picture. Studio Equipment Changes Cameras: New apertures at a cost of about $25 per camera; new ground glasses; adjustments to re-center lenses. Laboratories: Minor adjustments de- pending on the present practice followed by the laboratory. Art Departments: New camera angles. In Viewing Rooms: Adjustment of projector apertures and Theatre Equipment Changes 1. Theatres now using reduced pro- portional apertures: (a) File out aper- tures to larger size or insert new plates; (6) Enlarge screen by about four per cent, of area. 2. Theatres now projecting in Movie- tone proportion: (a) Insert new aper- ture plates; (b) Either move the screen masks in from the top and bottom; or (c) install shorter focal-length lens and widen the screen. 3. Theatres now projecting full-frame silent or full-frame with disc sound: (a) Insert new aperture plates ; (b) Re- center head of projectors; (c) Either, move screen masks in on all sides, or (d) install shorter focal-length lens to enlarge image to present screen. Possible Objections to the Proposed Change 1. A large part of foreign release is now on full-frame disc, and foreign ex- hibitors are accustomed to showing American product in this way. This is probably the most important objection to the proposed change, even though for- eign release is a comparatively small item. However, the same considerations of studio economy will also apply to foreign producers and it is probable that they will follow Hollywood's lead. For- eign theatres now showing full-frame can make the same adjustments Ameri- can theatres have made. If they make no adjustments at all the picture will not be hurt except to show a heavy black border on the top, bottom and left side. 2. There will be a period when prints with different apertures are circulating side by side. While this is true of any standardization, the committee consid- ered that the advantages will far out- weigh any temporary inconvenience. Theatres will be given the necessary in- structions in advance and should not make the changes until they begin to re- ceive most of their bookings on the new standard. 3. Many theatres are unable to afford expensive changes in equipment. In an- swer to this it may be pointed out that this change puts no burden on the the- atre. The new frame can be projected if necessary without any changes in aper- tures or screens whatever, and the only harm will be that a black border may show around the picture. The theatre can get rid of this by installing new aper- ture plates at a maximum cost of $3 and putting a rim of black paint around the screen or moving the screen masks in at very slight expense. 4. If an individual theatre does not want to install shorter focal-length lenses, and has been showing silent pic- tures or sound-on-disc pictures through the old silent aperture, the change will reduce its screen size by about eighteen per cent. If a theatre has been showing sound-on-film through a Movietone aper- ture the change will reduce its screen The New Standard 3x4 Aperture - -' THE proposed new standard 3x4 aperture constitutes a technical advance of major importance. TTie introduction of sound pic- tures presented many difficult problems to the motion picture tech- nical worker, but certainly none as serious as the matter of screen image, for a badly-proportioned screen image hit the industry where it hurt most — in the pocketbook. One need only glance at the accom- panying analysis of theatre aperture practice {Table A), to become convinced of the extreme seriousness of this problem. Projectionists will naturally delve into the specifications of the proposed new standard in order to learn just how their work is af- fected. Complete details are supplied in the accompanying article, thus only the highlights of this phase of the standard need be cited here: (1) Uniform prints, the lack of which heretofore has occa- sioned serious damage to projection in particular and the industry in general; (2) a larger screen image without additional magnifica- tion; (3) vastly improved facilities for framing, which until now has been largely a hit-or-miss affair by the projectionist, and (4) a single standard aperture which will eliminate movable flippers and changes of screen masks, aperture plates and lenses during the show. These various improvements may be effected with an inconsequential ex- penditure and a minimum of effort. Changes in production equipment and procedure are included in the accompanying article so that the projectionist may be fully informed regarding all phases of this problem and thus be better able to appreciate the various factors entering into the process and ultimately affecting his work. A word of warning anent this proposed new standard: No changes should be made in the theatre until the standard is officially adopted, immediately after which the necessary information will be sent to every theatre in the country. Barring unforseen develop- ments, prints made according to the new standard should reach the first-run theatres after January 1 next. We feel that we should not let pass this opportunity for paying tribute to all those who participated in the work of setting-up this new standard. This long and arduous task is one more red-letter achieve- ment by the Academy of Motion Picture Arts and Sciences. One need not look far for the reason for the remarkable success enjoyed by the Technical Bureau of the Academy. Under the very able di- rection of Mr. Lester Cowan (now Executive Vice-President of the Academy), this department has won its spurs by concerning itself with the practical side of technical problems, the while it left the theoriz- ing, the speechmaking and the production of high-sounding but ino- cuous platitudes to those who were content to do this rather than be concerned with that which obviously is their true function. JAMES J. FINN 20 INTERNATIONAL PROJECTIONIST November 1931 area about seven per cent., unless shorter focal-length lenses are installed. In answer to these statements it should be pointed out: first, that the area being matted off has not contained any vital action during the past year and so has contributed little to entertainment value; second that standardization of the 3 x 4 proportions responds to a strong demand from the theatre field ; third, that to the increasing number of theatres using a re- duced proportional aperture the change will mean a four per cent, larger screen image without additional magnification. Addenda The following item', although not a part of this article, provides an interest- ing sidelight on screen proportions. A supervising projectionist of one of the largest theatre chains in his reply to our inquiry raises a very pertinent question. He says: "The matting off at the top and bot- tom of the picture seems essential to members of the profession but the thought occurs to us, 'Does the shape of the projected picture matter to the gen- eral public?'" Our curiosity aroused, we put the question of the comparative advantages of the square and rectangular screen among others, to Dr. Walter R. Miles of Stanford University. Dr. Miles is professor of experimental psychology and an outstanding authority m his field. He was passing through Hollywood on his way east to attend international con- gresses of physiology and psychology. His comments on the proportions of the screen are given below. According to the view of Dr. Miles, the physical nature of the eye as well as long habit is against the nearly square shape of the sound-on-film picture for the motion picture image as compared with the rectangular shape silent picture. He says: . • i j: "No generation of man is entirely tree from former generations. Whether this is accident or intention it is hard to de- termine. If we make a survey of the tools and household articles that were used in Egypt as compared to those that are used today we find, perhaps to our surprise, considerable uniformity m shapes and sizes. For example, there is an optional size and weight for the hanri- mer that is used in one hand. There is an optional size and shape for the hand mirror to be used by a woman. Many illustrations of this come to one's mind. "The proportions of the rectangle have been a subject of scientific study since about 1875. At that time it was noted that man, in using the rectangle in near- ly all of his buildings, furniture, and con- veniences, adopted a ratio which was strikingly different from the perfect square. Although there is no correct exactness in this ratio it tends to be about five to eight, a combination which has been called the golden cut, frequently 1 We are indebted to Mr. Lester Cowan, Exe- cutive Secretary of the Academy of Motion Pic- ture Arts & Sciences, for this very interesting addition to this article. — Editor. found in crosses, windows, et cetera. The formula has been: the short side is to the long side as the long one is to the sum of the two. This must not be re- garded as a law to be striven for or which will bring punishment if it is transgressed. "If we seek for a basis in the physiol- ogy of the eyes and in the psychology of perception the following points come to our notice. The eyes have one pair of muscles for moving them in the horizon- tal, but have two pairs for moving them in the vertical. Vertical movements are harder to make over a wide visual angle. As man has lived in his natural environ- ment he has usually been forced to per- ceive more objects arranged in the hori- zontal than in the vertical. This has ap- parently established a very deep-seated habit which operates throughout his visual perception. Perhaps we can see the whole thing typified in the opening through which the human eye looks; it is characteristically much wider than it is high. "One final feature in the psychology of visual perception is that the vertical axis is over-estimated. A true square looks about three units too high. "We therefore see conformity with man's general experience as well as with the accepted art practice in projecting a picture that is wider than it tall." Upon his return from the East Dr. Miles took pains to reassure us that some of the leading physiologists and psychol- ogists of the world with whom he had discussed this very interesting subject had in general confirmed his opinions. This is very interesting especially in view of the fact that the proportions of some of the wide films in use are two to one and the opinion expressed by Dr. Miles gave eight to five as the proportion for maximum efficiency. DIVIDENDS FROM PENNIES Kendall Emerson, M.D. MANAGING DIRECTOR, NATIONAL TUBERCULOSIS ASSOCIATION [^The reason for the inclusion of this short article in this publication is ob- vious. Every year at this time attention is focused on the very important work which is being done as a result of the sale of Christmas seals, and every pub- lisher worth his salt gladly cooperates with the National Tuberculosis Associa- tion in the form of space donations for advertising and editorial copy. The splendid work of this organization is of special significance to the projectionist craft, so many members of which have good reason to be thankful to those ivho purchase Christmas seals. — Editor.] WHAT do you get when you buy Christmas seals? Most obviously, of course, you receive little pieces of paper which you stick on letters and packages during the holiday season, both as an expression of good-will toward humanity, and an example to induce others to buy them. But there is something else you get which is shared by all — and that is im- proved community health, which, to get right to the point, means you have a greater chance to live a longer life. Seals are sold to fight tuberculosis. This disease is still the arch-enemy of man, killing more people between the ages of 15 and 45 than any other ailment. Each year sees a falling death rate from this cause, and there is every reason to expect this record of success to continue in the future, if the pennies of the public do not fail in supporting the warfare against the scourge. But the battle has not yet been won by any means. It is imperative to continue the work which the Christmas seal has been doing. Unknown tuberculosis cases must be fer- retted out and placed under care in the early stages; children who already show evidence under the X-ray that they are candidates for active disease a few years hence must be found and safeguarded; summer camps and clinics in ,mai)(y places need support; public health nurses are required in others. These things and many others the Christmas seal penny helps to do. Foremost, per- haps of its achievements, is the campaign of general education which is ceaselessly waged to inform the public of the nature of the disease; how it spreads by con- tact from the sick to the well; how the sick must be discovered and the contact broken. Getting patients under treat- ment in sanatoria is important, but the greatest advance against the disease is along preventive lines. By raising the standard of popular knowledge people are enabled to protect themselves, ad- vancing the arrival of the day when sana- torium care will be unnecessary. Tuberculosis in the United States wipes out the equivalent of a medium- sized city every year. It has been esti- mated that to endure the disease as it now exists for the next twenty years would cost the nation more than twenty billion dollars. In the last twenty years education and sanitation have combined to cut the death-rate in two. Will the public continue to give the pennies, the- dimes . and the dollars needed in the next twenty years to abol- ish tuberculosis, or will it allow tubercu- losis to take from it twenty billions of dollars and hundreds of thousands of lives? That is the challenge which the nation answers every Christmas, when everybody, rich and poor, buys Christmas seals. ^ e Vol. 1, No. 2 EDITORIAL PAGE NOVEMBER 1931 The problem of film mutilation i his Matter has been with us since the intro- of Film duction of the motion picture. Mutilation Some of the best executive and technical brains of the industry have studied the problem in detail in an attempt to pro- vide solution, but to no avail. Repeated failure reflects no discredit upon the gentlemen who have bent their talents to this task, for the matter is one that requires a detailed knowledge of all branches of motion picture en- deavor— production, distribution, equipment and film manufacturing, and reproduction — which is asking a bit too much of any one mortal. This job requires collective effort by specialists in every branch of the art, and the lack of such effort heretofore is a plausible reason for the many failures recorded. The motion picture industry is not unlike any other great industry in that it suffers as a result of that artful little game which is popularly known as "passing the buck." Mention film mutilation in any gathering of technicians and immediately "the buck" is started on its journey. Film manufacturers pass to equipment manu- facturers; from here a pass is made to the exchanges, who, in turn, pass to the projectionist, who has no alter- native but to defend himself by "passing the buck" right back. The participants are very adept at this game, but their efforts contribute nothing to a solution of the prob- lem of film mutilation. Now along comes the Projection Practice Committee of the S.M.P.E., under the chairmanship of Harry Rubin, with an announcement of a program for investigating this whole matter of film mutilation and, if possible, provid- ing the answer. This intent of Chairman Rubin is com- mendable, and we wish him every success in his efforts. We wish we could prophesy with certainty a tremendous success for this program, but our experience in such matters prevents us from doing so. Let us assume that the Projection Practice Committee pierces the very core of this problem and as a result thereof promulgates certain recommendations anent future practice. Such a report would be read before the Society, printed in the Journal and then, if past experience be any guide, be promptly forgotten by everyone except those men who had worked hard and long to prepare the recommendations. This will never do. One does not have to look far for the reason why this should be so. The reason lies in the fact that not one important executive in the motion picture industry has a clear perception of technical activity within the indus- try. Most of these executives think they have discharged their obligations to the technical forces when they have written a complimentary letter to be read at a technical society's banquet, or when they are quoted in some trade paper to the effect that they think "the technicians have done splendid work for this great industry of ours and we wish them every success" — or some such palaver. These same executives know their business in every other respect, though: actor's salaries, wages, equipment costs, distribu- tion costs, box office reports, and the like. But what they don't know about the technical phase of the business would fill several libraries of good size. These men for- get that the technicians make money for them by improv- ing quality and reducing the cost of getting that quality, just as surely as does the star who wears well at the box office. But try to convince them of that. The Standard Release Print saved the producers $100,- 000 within six months after its introduction. Yet, when this writer interviewed one of the ranking executives in the business on the subject and at the same time attempted to secure a small donation for the Projection Advisory Council (which organization aided greatly the intro- duction of the S.R.P.), he found that this "ranking executive" had never heard of the S.R.P. (P. S. Also, he didn't get the money.) Such is this business. We have strayed far from the subject of film mutila- tion, but the foregoing serves very well to indicate just what the technicians are up against in formulating a definite program. Film mutilation, and any similar prob- lem, requires more than anything else an active interest by and the support of the excutives of this business. With such support assured, many existing technical problems would be comparatively easy of solution. As for the specific matter of film mutilation, the answer lies not in committee reports, trade paper comment, fire insurance statistics or/and complaints from the technical field workers. Assuming the existence of an active inter- est on the part of the industry's executives, the matter should be put squarely up to a board to be composed of representatives of, say, the following: (1) producers (2) exhibitors (3) exchange operations supervisors (4j projector manufacturers (5) projection supervisors (6) technical societies (7) fire underwriters, and (8) film manufacturers. There may be one or more omissions to the foregoing list. With such a board applying itself diligently to the problem, the answer should be forthcoming quickly. And once established, the board's recommendations should be enforced. Such a board would put a stop to all this silly "buck passing" and would place the responsibility square- ly where it belongs. A. P. S. Looks to the Future We note with considerable pleas- ure that arrangements have been made for reorganization of the American Projection Society. Di- rection of the Society, long vested in the Eastern faction, has now passed to a West Coast group which has demonstrated its capacity for leadership. An up-and-doing educational and fraternal organization is an absolute necessity to the projectionist craft, and we look to the American Projection Society to provide such a service. [21]. THE ART OF CONTINUOUS CINEMATOGRAPHY William C. Plank IN this article we shall submit to pro- jectionists various reasons why the art of continuous cinematography ad- vances precision in projection to a higher standard. In cinematography, precision will always remain the predominant thing; and old and less accurate meth- ods must invariably give way to newer and more precise ones. That is the hand- writing on the wall that everyone can read. Precision is always useful, but never more so that when it is dedicated to the comfort of the eyes and the pres- ervation of vision. And in no other di- rection can it be applied to a more gen- erally useful purpose than in improving motion picture projection. It is axiomatic that the most precise and perfect method of dividing a mo- tion picture film into evenly spaced di- visions or frames is by imparting a uni- form motion to it, and spacing off the divisions by the beats of a pendulum or the regular periods of a rotary body re- volving at a uniform velocity. This is the fundamental principle of the registration in the continuous cinematograph. And the thing that makes it important and full of interest is that the ideal can be approached more closely upon this prin- ciple than upon any other. Freeing the registration from the tyranny of the perforations and perma- nently establishing it upon the basis of uniformity of motions or the law of in- ertia, is the outstanding achievement of the continuous cinematograph. Many improvements proceed from this revolu- tionary innovation in the principle of registration. The most important of these are undoubtedly the ones that con- spire to greater perfection in the pro- jected image, for they directly concern the public. Major Advantages It should be a matter of interest to the public, therefore, that the art of continu- ous cinematography offers six optical im- provements, all of which contribute to the comfort of the eyes and the preser- vation of vision, or to the quality and beauty of the image. These are: I. A characteristic steadiness or smoothness in the projected image, de- rived from the extraordinary precision of the registration. The cumulative ef- fect of the more precise registration im- proves the definition, increases the con- trast, and lessens eyestrain. II. A restful quality that is more pleas- ing to the eyes. This is due to the con- tinuity of the illumination made possible by the elimination of the dark-periods. It is a quality that is immediately per- ceived and remarked upon by many. III. The much longer stationary-period which is made possible, improves the half-tones and increases the depth and "snappiness" of the image. IV. A more perfect and natural re- production of motion. This is one of the most important of the improvements made possible through the art of con- tinuous cinematography, for it adds life and action to the image. It tends to cor- rect the jerky mechanical quality of mo- tion pictures. The reason will be found to reside in two distinct phenomena. The first of these is the creation of composite or intermediate postures during the blending period. These composite images take the place of the usual dark- periods in intermittent projection, and thus very appositely fill in the blanks in the record. In Figure 1, the thin hand of the col- ored boy illustrates one of these inter- mediate postures, for it will be observed that it is half-way between the faint out- lines of the two original postures from which it is created. Our rhomboidaF prism projector was stopped at the dis- solve-period and the two images of ad- jacent film photographs were thus super- posed upon the screen, and photo- graphed. It will be noticed that corresponding parts of the two superposed images re- main unaffected by the blending, but those parts that do not coincide (the parts that were in motion in the object), become partly obliterated by the high- lights of the complemental frame. Where these parts overlap, however, the high- lights cannot affect them and a con- spicuous intermediate posture or pose is created. The thin hand of the colored boy constitutes such a composite pos- ture, for it can be proved by shutting off ^ A four-sided figure having its opposite sides equal, and its angles not right angles; lozenge- shaped. •i ^ i',- ii:^ 'f!rl':'M / Figure 1 Figure 2 [22] November 1931 INTERNATIONAL PROJECTIONIST 23 the light to each frame, that the upper outline of the hand and wrist belongs to one film image while the lower one be- longs to the other. Above and below the thin hand and wrist, the faint out- lines of the two original postures can be made out. Note also, that the index finger of the hand does not appear in the intermediate posture because it failed to overlap. The case in which light parts move upon a dark background may also be demonstrated. Irradiation The second phenomenon that enters into this art cannot be accounted for ex- cepting upon the principle of irradiation.' A narrow fringe or border (either of light or shadow) , adjoining a larger area, will make the larger area appear to ex- pand or move, with a variation in the il- lumination of the fringe. We often see examples of this phenomenon in adver- tising signs with raised letters that cast shadows. The variations in the illumina- tion give an apparent motion to the let- ters. For similar reasons the thin arm of the colored boy will appear to expand upward or thicken to the limit of the up- per outline of the fringe, if the' fringe be gradually darkened until it is the same shade as the rest of the arm. This apparent motion depends upon the varia- tion of the illumination, and hence it is gradual and continuous and the equiva- lent of a succession of postures. It will be understood, of course, that these simu- lations of motion can occur only when there is an overlapping of the parts, and when the separation of the original pos- tures is not too great. In watching this interesting phe- nomenon, and passing the film photo- graphs through very slowly, it will be noticed that many of the couples give only a very crude representation of mo- tion; but then again, others delight us with the grace and ease of the move- ments. Thus it is that this new art fills-in the dark-period with a real intermediate pos- ture and a continuous succession of ap- parent ones. And in doing this, it per- forms a twofold service, for it eliminates flicker, and adds movement and life to the image. This unique property is the basis for a fair imitation of slow motion when the rate of projection is reduced to three or four frames a second. And in amateur cinematography it is invaluable, for it makes possible the taking and pro- jecting of motion pictures at the sur- prisingly low rates of four to eight frames a second. The substantial saving thus effected represents the toll that flicker is now ex- 'A ray of light; emission of heat rays; apparent enlargement of a bright object upon a dark ground. Showing two frames fully superimposed during the dissolve period. This tends to reduce graniness. The half-values of the highlights cannot be caught in a photo- graph, however: they show as white as the full values acting of the amateur. More than half of the cost for film goes out for apparent- ly no better purpose than to speed up so as to make the flicker imperceptible to the eyes. Depth Possibilities V. Unusual third-dimensional effects, which are inherent in the dissolving or blending principle of the substitution. The two images superposed upon the screen at the same time are, undoubted- ly, the chief reason for the noticeable roundness or plasticity of continuous pro- jection. In Figure 2, the lap-dissolve is illus- trated more strikingly by a frame of titles superposed upon a picture. If the film gate were here titled slightly with respect to the optical axis, the focal planes of the two images would separate, one of the images moving farther back of the other along the optical axis. It will be seen, therefore, that if the film photo- graph be moved downward from the up- per position of the double aperture to the lower one, its image will occupy, successively, the more remote plane, the intervening planes, and then the nearer one ; and that at full projection speed, all of these planes will be filled with a sharply-defined image. This is another of the unique effects that can be obtained in this art, and which may be employed to accentuate the third-dimensional ef- fect with an appropriate screen. Better Color Results VI. Better results in natural color pro- jection, for the reason that the restric- tions as to the rates of projection are removed, and methods giving better defi- nition may be employed. In a recent article' the present writer " "Some Interesting Properties of Continuous Pro- jectors," Journal, S.M.P.E. {June, 1931), Vol. XVI, No. 6. has summarized the mechanical advan- tages of the continuous cinematograph as follows: 1. A higher order of precision. 2. A more uniform and longer sustained accuracy. 3. The mechanism has fewer parts and is of the heavy duty type. 4. Oiling nuisance is avoided, and the sound track and picture surfaces are kept free from oil. 5. Noiseless operation. 6. Freedom from vibra- tion, as all the moving parts are balanced and re- volve at a uniform velocity. 7. Momentum of the prism-wheels tends to overcome certain in- accuracies in the mechanism. 8. Momentum of the film overcomes many inaccuracies in the per- forations. 9. Wear on the perforations has less effect on the projection. 10. Momentum of film prevents sudden lateral movements. 11. Elimination of tension shoes pos- sible, as a loose loop of film can be made to press itself with sufficient flatness against the aperture plate. 12. Elimination of tension shoes makes possible the use of raised or embossed margins on the film, thus forming an air-space and prevent- ing scratches on the sound track and picture sur- faces when wound up. 13. Absence of tension shoes eliminates the effects of variations in the thickness and smoothness of the film; and the effects of variations in the "give" or flexure of the film at the perforations when under a severe strain. 14. Minimum of strain and wear on film. 15. Fire hazard reduced as there is less possiblity of the splices parting. 16. Moving film fans itself, so withstands higher tempera- tures. 17. Even distribution of heat reduces buckling of frames. 18. Most of the work of pulling the film may be allotted to the frictional contact of the sprocket drum. 19. Minimum of work for the sprocket teeth prolongs their life. 20. Fewer and smaller perforations may be used. 21. The need of only one row of perforations, thus giving room for a wider sound track or a wider picture. 22. The use of one row of perforations eliminates errors in parallelism in the perforations and in the sprocket teeth, and makes for greater precision In the registration. Misleading Propaganda The advantages of the continuous cinematograph are, in fact, so many and so obvious that it is no wonder inventors throughout the world have directed their attention to its development. Several continuous cinematographs have been de- signed of such rugged and simple con- struction as to leave no doubt that they will stand up well under use. The charge that the continuous pro- jector is impractical has been widely cir- culated in technical journals, to the prej- udice of the art of continuous cinematog- raphy, and to the misleading of motion picture engineers. But obvious propa- ganda should deceive no one. And every one should know that the acid test for practicability is practice — the capacity for useful service. In its capacity for delivering uniformly accurate projection through a long period of time, the con- tinuous projector stands out conspicu- ously among cinematographs. Its period of accurate use may be estimated at from five to fifty times as long as that of vibrating mechanisms. No greater claim to practicability can be made. [Note. — The second and ccmcluding article in this scries zvill appear in the next issue. — Ed.] MATHEMATICS FOR THE PROJECTIONIST Siegfried S. Meyers INSTRUCTOR IN PHYSICS, STUYVESANT HIGH SCHOOL, NEW YORK IT is the purpose of this article to ex- cite the interest of the projectionist in an elementary study of mathe- matics. Explanations of certain equip- ments, prints, graphs, schematics and the like are often presented to a projection- ist who has never had an opportunity of familiarizing himself with the elements of mathematics, the lack of knowledge of which often renders valueless much material which otherwise would offer much of interest. This series of articles will attempt to make up this deficiency. This and succeeding articles will be prepared on the assumption that the reader knows nothing about mathematics. Those who are familiar with some of the material presented herein are asked to bear with their fellow craftsmen and the author until the series is more advanced ; but in any case, even this elementary ma- terial will serve this class of readers as a review. In the average textbooks on algebra and geometry is found a mass of data which is of little practical use to the pro- jectionist. For this reason the repro- duction herein of a major part of such textbooks would be unjustified. A spe- cial effort has been made to deal only with the practical aspects of mathe- matics, and it is believed that this course will best serve the purpose of these articles. Mathematical Language It is necessary that the reader have an adequate knowledge of the language of mathematics — and by this is meant an understanding of the terms and symbols used, just as in music there is a language comprised of terms and symbols. Let us first consider that which is commonly re- ferred to as a "formula." What is a "formula"? A formula is simply a mathematical equation, which we may consider as a hopper, into which one pours certain information, then turns the crank — and out comes the answer. The mechanical analogy of a formula to a hopper is indeed illustrative. Work- ing out a formula is a process from which the unknown is derived by supplying the known factors. Beyond the use of formulae lie terms like "perpindicular," "bisection," "ver- tex,' and the like. Let us first familiarize ourselves with these terms. By definition, a "straight line" is a continuous succession of points. "Points" are the boundaries of these lines. A "curve" is spoken of as a series of in- finitely small straight lines. An "angle" is the space bounded by two insersecting straight lines. By "bisecting an angle" is meant the cutting of an angle into two smaller equal angles, the sum of which is equal to the original angle. In "trisect- ing an angle" we do the same thing, but in three equal parts. This latter process is very difficult. The "vertex" of an angle is the point of intersection of the two bounding in- tersecting lines. "Perpendicular" is a line which is set at right angles to to an- other straight line. In any circle there are 360 degrees. If two diameters inter- sect each other within a circle, and do so perpendicularly, we have four right angles included by these diameters (Fig. 1). Ratio and Proportion Ratio and proportion is a common algebraic process knowledge of which is extremely valuable to the projectionist. For example, this process is used to de- termine the proportionality of two fac- tors, when two other factors vary in some definite ratio. By this is meant that a certain unknown number can be found when three others are known. Example : If a current of one ampere can flow through 10 ohms resistance, how many amperes will flow through 5 ohms resis- tance? Discussion. 1. The variable terms are the resis- tances. 2. As the resistance becomes one-half as great, the current becomes twice as great. Solution : 10 ohms is to 5 ohms as X amperes is to 1 ampere, or 10:5 = X:l (No. 1) This may also be written as: 10 X = (No. 2) 5 1 In solving for X, it is necessary that we make X equal to all other terms. In equation No. 1 the colon ( : ) represents the ratio, and is read as follows: "10 is to 5." This means that 10 ohms is com- pared with 5 ohms. The "equals" sign ( = ) represents the proportion or com- parison and is read: "As." Now, read- ing equation No. 1 in its entirety we say: "10 is to 5 as X is to 1." Equation No. 2 is read the same way, the division sign meaning the same as the colon, namely: "is to." In solving equation No. 1 there are two parts — the "means" and the "ex- tremes." The "means" has reference to the two numbers located on either side of the equals ( = ) sign. The "extremes" are the two numbers at the ends of equa- tion No. 1. We multiply the means by each other, and let them equal the prod- uct of the extremes. This gives us: 10 X 1 "Extremes" Or: 5X = 10 10 X = = 2 amperes, 5 Answer. It will be seen that this proportion does not increase directly as the ratio increases. The ratio of the resistances Fisure 1 LINE CURVE VERTEX BISECTING AN ANGLE A CIRCLE HAS 360 DECREES [24] November 1931 INTERNATIONAL PROJECTIONIST 25 Figure 3 Z -2- I-! 8 SQUA /NC fSE H£S -4- decreased from 10 to 5, or 2 to 1. Yet the amperes increased in the proportion of 1 to 2. This is an example of "in- verse" ratio and proportion. This is not the same as "direct" ratio and pro- proportion. For example: Problem: If 5 cents buys 1 apple, how many ap- ples can be bought for 15 cents? 5:1 X X 5X X 15 :X 15 X 1 15 3 apples, Answer. The foregoing is an example of "di- rect" ratio and proportion. Where the number increases directly as the price increases, it will be seen that we com- pare the price of one article with the price of X articles. In solving any prob- lem like the foregoing, it is always good policy to ask oneself the following: "A is to B as how many is to C?" Or: A:B = X:C. Or: B (No. 3) (No. 4) In solving equation No. 3 we get: B X X = X(AXC) Or: BX = AC If we divide both sides of this equation by B, we get: BX B AC B AC Or: X = (since B cancels on the B left side) In solving the same proportion by , A X means of equation No. 4 (ff) C a simple method is available. By cross- multiplying we obtain the same result. By this is meant: draw a line from B to X and multiply them together. Draw an- Figure 2 other line from A to C, multiply them together, and let the product of the first two letters equal the product of the sec- ond two letters. Thus: Figure 5 B xX = A X C Or: B X = AC AC X = (dividing both sides by B), B Answer. Plane Geometry The Square. The areas of various geometrical figures may be determined by employing simple formulae. For exam- ple: a square is said to be a figure the length of which equals its width. There- fore, a figure having a length of 1 inch and a width of 1 inch is said to be a one- 4- ARE INC HES. ■ ' U 2'^ J 9 3' S QUA RE 4CHES 1 , ' f h- 3" ^ UNIT C/M(TS Figure 4 inch square! In mathematics we call this area one square inch. Suppose we extend the length of this square to 2 inches, and also make the width 2 inches. Would we now have 2 square inches? We would have 4 square inches. If the length be 3 inches, and the width 3 inches, we have an area of 9 square inches. (Fig. 2.) The conclusion of this is that the area of a square is ob- tained by multiplying the length by the width. The Rectangle The same that is true for the square is true for the rectangle. A rectangle really is made up from a number of squares. If UNITS the length of a rectangle is 2 inches and its width 1 inch, the area is 2 square inches. If the length is 4 inches and the width is 2 inches, the area is 8 square inches. In other words, the area of a rectangle is equal to the product of its length multiplied by the width. (Fig. 3.) The Triangle The area of a triangle can be com- puted in a similar manner. Let us con- sider a square the length of which is 2 inches and the width of which is 2 inches. The area of this square is 4 square inches. Now let us draw a diag- onal line within the square so as to di- vide the square into two triangles having equal areas. (Fig. 4.) Since the sum of two rectangles is equal to the entire area, then the area of each triangle is one-half the area of the square. Each of these triangles differs from the square in a certain respect. It appears as though a triangle is a square having one of its sides squeezed down to a point. Therefore, the width of the triangle is not 2 inches all the way through. Its width varies from 2 to zero. Its average width is 1 inch. The area of a triangle, then, is measured by mul- tiplying its length by its "average width." A triangle is said to have an altitude and a base. These correspond to the lengths and the widths of squares. The area of a triangle, then, is the product of the "average base" multiplied by the height or altitude. Expressed by equation: Area of triangle = % b h . . (No. 5) where: b = base h = height or altitude In the above figures, then, the area of either triangle is 2 square inches, for: A = 1/2 X 2 X 2 = 1/2X4 = 2 square inches. Answer. The Circle The area of a circle depends upon its diameter. If we increase the diameter, the area increases. Therefore, if we know the diameter or the radius (which is half the diameter), we may determine the area. Let us see how the area of a circle in- creases with the diameter. Suppose a circle has a diameter of 1 unit and its area is 1 square inch. If we double the diameter, the area does not double. If the diameter becomes twice as great, 26 INTERNATIONAL PROJECTIONIST November 1931 measurement shows us that the area is four times as great. If the diameter is tripled, the area becomes nine times as great. In other words the areas of circles do not vary as their diameters, but rather as the squares of their diameters. (Fig. 5.) We have noted that the areas are pro- portional to the squares of their diam- eters. Similarly, they are proportional to the squares of their radii, r' indi- cates the product of r X r, which rep- resents the radius multiplied by the radius. In order to express a proportion in the form of an equation, we introduce a "constant" called pi (tt), a Greek let- ter, and assign to it a value of 3.1416, because the areas increase by this con- stant value as the radii increase. Hence we have the formula: Area of a circle = ^ X r" or: A = 3.1416 X r', square inches. Answer. Solid Geometry Solid geometry is simply a further ap- plication of plane geometry. Instead of dealing with plane objects like a square and a circle, solid geometry deals with objects having three dimensions like the cube and the sphere. By three dimen- sions, we have reference to length, width, and depth. Professor Albert Einstein, the celebrated physicist, has added a fourth dimension which he calls "time' ; but this principle need not be discussed herein. The Cube The cube really is a pile of squares. The area of a square is obtained by mul- tiplying its length by its width. To de- termine the volume of a cube, the dimen- sions of which are 1 inch long, 1 inch wide and 1 inch deep, we multiply the length by the width, which gives us 1 square inch. We then multiply this area by the depth to get the volume. As a result, the volume of this cube is 1 X 1 X 1, which is 1 cubic inch. Formula: V = 1 X w X h where: v = volume 1 = length T/f = width h = height or depth The volume of a cylinder is obtained in the same way. The area of the base is ■^t\ We then multiply this area by the height to determine the number of circles in this cylinder in cubic inches, by using the following formula: V = TTl'^h where: v = volume of cylinder TT = 3.1416 r = radius of the base h = height of cylinder [To be Continued) ALLIANCE ITEMS I. A. Executive Board Meets at Vancouver THE regular meeting of the General Executive Board of the LA. was held in Vancouver, B.C., on October 12. Several sessions were held during the course of the American Federation of Labor Convention which had assembled in Vancouver for the customary two-week period. The initial roll call revealed all mem- bers of the General Executive Board present, as follows: William F. Cana- van, International President; William C. Elliott, William Covert, John P. Nick, William J. Harrer, Joseph C. Campbell, William T. Madigan, Floyd M. Billings- ley, and Fred J. Dempsey, General Sec- retary-Treasurer. Due to the resignation of former Third Vice-President Cleve Beck, and the ap- pointment of Floyd M. Billengsley as Seventh Vice-President, each member of the Board, from the office of Third Vice- President on, was automatically ad- vanced, this being the first meeting at which a proper recording of this change was made. The meeting of the Board was officially adjourned on October 14th. Charter Installation at Johnson City, Tenn. FORMERLY under the jurisdiction of Bristol, Tenn., Local No. 530, appli- cation was made for charter to cover Johnson City, Tenn., and as investigation revealed the applicants had conformed with all International requirements and were qualified in every other respect, recommendation for granting the char- ter was filed and approved. Proper in- stallation of the new local union was made by Representative William P. Raoul. A pledge of full support was re- ceived from the Johnson City Central Labor Union. Tube Warm-XJp Time Included in Schedule CORRESPONDENCE transpiring be- tween the General Office and H. M. Wilcox, Vice-President of Electrical Re- search Products, Inc., is printed herein for the information and guidance of LA. projectionist members. Compliance with the request contained therein will confer a distinct favor on the interests involved, as, aside from the economical feature it will effect an improved performance: September 30, 1931. Dear Mr. Canavan: We have been co-operating very closely with exhibitors all over the country in an effort to re- duce the repair and maintenance costs of sound equipment, and I am glad to state that we have been able to save exhibitors a very substantial amount; in fact, this will run into several thou- sand dollars this year. In connection with this it has been pretty defi- nitely proven that the life of vacuum tubes can be extended from 15% to 20% if there is a proper heating up time prior to the use of the amplifiers. This heating up does not need to ex- ceed fifteen to twenty minutes. Frequently we have statements mad to us that it is impossible to get the operators to give atten- tion to this matter and it occurred to me that you might desire to prepare a general bulletin on this subject, as I know that you, too, have been co-operating with exhibitors generally with reference to the reduction of operating costs, and this will give you an opportunity of giving con- crete evidence in a very practical view of help- ing them to reduce costs. It is in view of this, that I venutre to pass this suggestion along. Cordially yours, (Signed) H. M. WILCOX, Vice-President. Dear Mr. Wilcox: Answering your letter of September 30th, I as- sure you that the warming up time is inclusive in all projectionist schedules. My contact with, the matter indicates that the time allotted to this service is thirty minutes. It is only too obvious that a proper performance cannot be given under any other circumstance, and you can count fully upon my official aid in seeing to it that all the projectionist local unions have a provision re- quring the men to properly prepare the sets for operation prior to the opening of the show. Thanking you for your interest in this matter, I am, with best wishes, Very truly yours, (Sgned) WILLIAM F. CANAVAN, International President. New York and Chicago Locals Victorious WITHIN the space of a few days of the report of the settlement of New York Local No. 306 in their dispute with the Lee 0. Och's interests, word of the favorable termination of the contro- versy existing between Chicago Local No. 110 and the Independent Exhibitors was received. In each instance, a bitter and resourceful fight was waged by both sides, with the outcome eagerly looked forward to by supporters of Organized Labor and their employers, as it was an- ticipated the result would have a sig- nificant bearing on subsequent issues. The strained relations previously ex- istant between the local organizations and the controlling interests have been healed and a spirit of harmony and good- will now prevails, with each co-operating for the success of the industry, which, of course, must be assured and has priority over any individual gain and glory sought. On this common understanding, both may be confident of success. Indiana Legislative Body Is Reorganized DISBANDED sometime ago at the dis- cretion of President William F. Canavan, "The Indiana State Legislative Organization" has been reorganized with the permission of the General Office. This new body will function solely as a legislative organization. The formation of this new organization occurred at a meeting held in Fort Wayne, Ind., at- tended by all Indiana local unions. L. P. McGirr, of South Bend, was elected Secretary-Treasurer. No time was lost in formulating plans to combat the progress of dual organi- zations in Indiana. Safety will be the November 1931 INTERNATIONAL PROJECTIONIST 27 keynote of a campaign to be launched shortly in municipalities looking toward the betterment of the LA. A Member's Dream, of a Perfect B. A. ONE who is capable of creating jobs for the membership when there is none to be had. He must be specially fitted to have a job ready for a member when he reports out of work. He must have abality to defend himself on all occas- sions — physically and otherwise. He must have influence to get all members out of trouble at all times. He must have sufficient real estate unencumbered so as to be in a position to sign personal bonds. He should have sufficient ready cash to insure the membership small loans, meals, street car fare, lodging and ■cash checks, etc. He must furnish his own car and a telephone in his home. He must be available to the membership at all times. He must keep himself posted as to know where every member •can be located on a minute's notice. A Few Requisites He must also be capable of defending a member before all employers, when dis- charged for a good cause and force em- ployers to maintain men in employment. He must be able to collect all wages for members who are too lazy to do it for themselves. When sending members to a job, he should have sufficient wisdom to give members correct number of days ■employment and all the tricks to gain overtime which he is not entitled to. He must visit the sick, purchase tickets for bazaars, raffles, picnics and dances and make donations to all political causes and all other worthy causes from his per- sonal funds. He must keep posted as to the conditions of work in other cities and be personally acquainted with all councilmen and judges so he can get re- leased or get jobs for their neighbors and he will be held responsible for all new members accepted into the local. He must have a pleasing disposition and keep posted on the weather condi- tions as to tell in advance as to whether the sun will shine or whether it will snow or rain. He must be up on all current events and must know how long it will take a letter to get to Chicago, Detroit, Cleveland or other points. He must be up on all current events to know how to get the best results from radios, automo- hiles, etc. S. C. STATE COUNCIL HOLDS ANNUAL MEETING More than 100 projectionists and the- atrical employes from the two Carolinas, all members of the LA., met in Colum- bia, S. C, on October 25th, for a confer- ence looking toward betterment of the •craft. Paul W. Fuller, educational direc- tor of the A. F. of L., addressed the meet- ing on the subject of wage cuts and the resultant limited purchasing power. Fire Chief Marsh emphasized the need for the cooperation of projectionists with fire authorities in controlling serious the- atre fires. W. P. Raoul, LA. representa- tive, outlined the work of the projection- ist craft during the past two years. Officers of the State Council of the- atrical workers for the coming year elected at the meeting were: A. H. Estes, Columbia, president; Ernest Jenkins, Charleston, first vice-president; W. L. Dent. Columbia, second vice-president; George V. Spillers, S'paitanburg, third vice-president; Carroll L. Addy, Colum- bian, secretary and treasurer. The ex- ecutive board elected by the council will be composed of J. Henry Keener, Charleston; George H. Blackmon, Colum- bia; A. J. Lancaster, Spartanburg; and Guy Bryson of Greenville. Columbia was selected for the 1932 meeting place. Control of A, P, S. Passes to West Coast Group EARLY settlement of the problem of reorganization of the American Pro- jection Society is expected as a result of a meeting of a special committee of the Supreme Chapter in New York on Oc- tober 1. The New York faction hereto- fore has opposed vigorously the reor- ganization program sponsored by the West Coast chapters, and until very re- cently there was every indication that this difference of opinion would split the or- ganization into many factions each with its own program. The meeting on Oc- tober 1, however, developed into a "har- mony" session, and the net result is that the wishes of the West Coast groups with respect to reorganization will be acceded to. At the meeting on October 1 the fol- lowing members were present : H. Stein, chairman; P. A. McGuire, secretary; Joseph Basson, J, Girvan, and George Edwards, the latter having served until recently as International President. After a general discussion and a unani- mous agreement that every effort must be made to "meet the wishes of all chap- ters," the following suggestions were agreed upon and will be presented to the Board of Governors of the Society for consideration : A bolish Supreme Chapter 1. Upon recommendation of Brother Edwards the term "Supreme Chapter" is to be abolished and all chapters will be known according to number and location, to illustrate, "New York Chapter No. 1." 2. Brother Edwards advised that a recommenda- tion be made for a change in the constitution, which will enable all chapters to participate in the nomination and election of an International President. Each chapter will elect jts own rep- resentative to be a member of the International Board of Governors. 3. Brother Edwards further recommended that the International President be empowered to ap- point an International Vice-President, an Inter- national Secretary and an International Treasurer, preferably from the members of his own chapter. These officers to constitute an administrative body, acting in conjunction with the Interna- tional President. 4. Brother McGuire recommended that the appointment of an Administrative Board shall be confirmed by the International Board of Gov- ernors, who also shall have the power to re- move for cause. 5. The International Vice-President, the Inter- national Secretary and International Treasurer. shall have no vote in the Board of Governors. The International President shall designate the man- ager, editor, and location of the official publica- tion of the Society, The American Projectionist. 6. The Committee further recommends that the present Board of Governors take prompt action to enable these recommendations to be put into ef- fect without delay. That immediately following the change in the constitution, plans be formu- lated to arrange for nomination of an Interna- tional President and election by a secret ballot, which will enable all members of the American Projection Society, in good standing, to vote at the coming election. These recommendations re- ceived the unanimous approval of the committee. Behind all these words is the real story which is that the West Coast chapters will "run" the American Projection So- ciety for the next year at least. After the considerations, the proposals, the unanimous agreements, the letter-writing, the speechmaking, the nominations, and the elections are over with, the West Coast chapters will emerge as the direct- ing faction of the Society. Seavier for President Frank L. Seavier, President of San Francisco Chapter No. 16 and one of leaders, if not the leader, in the reor- ganization movement, is regarded as a certainty for International President; and as such he will have the power to appoint the vice-president, the secretary, and the treasurer of the Society. There is gen- eral approval among the membership, on the West Coast and elsewhere, of the choice of Seavier as their leader. The status of The American Projec- tionist, official organ of the Society, still remains in doubt, the decision as to this to be made by the new administrative body. Immediately following the induction into office of the new administrative body an intensive campaign for greatly en- larging the scope of the Society's work and a drive for increased membership will be launched. The new administrative body will be installed shortly after January 1 next, a majority of the chapters (including New York), having expressed their approval of the reorganization plan in general, and of the election of Seavier to head the Society. 28 INTERNATIONAL PROJECTIONIST November 1931 THIS SOUND AND TELEVISION SCHOOL 'RACKET' James J. Finn LATE in 1929 and early in 1930 the sound projection school "racket" flourished and every large city boasted of at least one such school. Thousands of students, baited with glow- ing promises of $100-a-week jobs, were enrolled in the various schools in all parts of the country. It is difficult to state with any degree of accuracy just how much money was contributed by In- ternational Alliance men to these institu- tions, but the amount may safely be said to be not less than $15,000. The "racket" reached such propor- tions that President William F. Canavan of the International Alliance issued a general ban against all such enterprises. Mr. Canavan felt that I. A. men should not contribute money to a school which would supply information, correct or otherwise, on sound projection to men who, in turn, would endeavor to displace I. A. men in their jobs. In addition, he stated, a majority of such enterprises had been proven to be "rackets" in the full meaning of the term. Conspicuously active in the sound pro- jection instruction field at that time was the Projectionist Sound Institute of Easton, Penna., headed by F. A. Jewell. Mr. Jewell's first move was to announce the formation of a "faculty" or advisory board manned by prominent technical men and designed to inspire confidence in the Institute's course of instruction. At least one well-known electro-technical worker who was also an I. A. man lent his name to this board; but he was quickly forced to resign. A Bid for Favor A short time thereafter this writer was visited by Mr. Jewell who outlined the general plan of his course of instruction, gave assurances that he "was on the level" and that his idea of instruction was sound, and solicited favorable "plugs" among projectionists in order to increase enrollment. Naturally, this writer was to have a "cut" on each stu- dent secured. It has occurred to this writer several times since that day that possibly Mr. Jewell has not a very warm feeling for his type of person. This was his last meeting with Mr. Jewell. Projectionist Sound Institute continued to operate, although it is doubtful that it enjoyed any great favor among I. A. men in the light of the for- midable opposition it had encountered in this field. Subsequent developments along this line consisted mainly of a few random shots taken by this writer at the general idea of such schools, just by way of a reminder to projectionists. It can be stated here that the stiff op- position of the I. A. to all such enter- prises has been proven to be justified. Before proceeding further, we should like to direct attention to the notes ac- companying this article: one a verbatim reproduction of a recent newspaper story, and the other a "lift" of a report by the Better Business Bureau from the I. A. General Bulletin, 1930 volume. These notes are self-explanatory. Tinker to Evers to Chance We come now to October of this year. What do we find? We find in existence the Photo Electric Research Laboratory Corp., the National Sound Service Bu- reau, Inc., and the Electric Sound Insti- tute, Inc., the latter located in Easton, Penna., and the others in New York City. The first-named is said to be de^4eloping a new engraver. The second organiza- tion was formed to "service theatres all over the country" in connection with sound picture apparatus. Can it be that the third unit, the "Institute" is, say, a first-cousin of our old acquaintance in Easton? It is; for we note that F. A. Jewell is the recognized head. My, my. The recognized head of all three en- terprises, according to the accompanying newspaper story, is F. A. Jewell, and hi& co-officers are Lester Al Smith, G. C. B. Rowe, and Eric C. Mackey. The activ- ities of the "Institute" and the "Service Bureau" are explained in the report of the Better Business Bureau. But this report does not trace the path of the "student" from the Institute to the Serv- ice Bureau to the Photo Electric Re- search Laboratory. It cannot be denied that this is a swell chain — only so dif- ferent from the old-fashioned business college which promised jobs to its gradu- ates. Now that we have the first two com- panies properly pegged, let us consider the activities of the Photo Electric Re- search Laboratory. We turn for our information to Photo- electricity and Sound, which obviously i& a house organ for all three companies — ■ the soldering element, so to speak. We note that this paper is published in Easton by a company of the same name as the title, and is officered by the fol- lowing : F. A. Jewell, president ; G. C. B. Rowe, secretary and treasurer, and L. A. Smith, vice-president. Familiar names,, all. In Volume 1, No. 1, for October, 1931, we note an article entitled "Photoelec- tricity and Gold," by L. A. Smith, which captures our interest. This article dwells on the virtues of the new engraving proc- ess which P. E. R. L. is developing and suggests that a little extra cash might be Indict ''Sound School" Promoters Four Promoters Indicted in $200,000 Swindle. PROMISED STEADY PLACES Ambidous Applicants Pay to Learn Electric Sound Work. A pretentious racket which reaped a large in- come from the savings of unemployed men through promises to train them in electrical sound work and secure for them $50 a week jobs was uncovered today in an indictment filed by the Federal Grand Jury charging mail fraud against the officers of the National Sound Service Bureau, Inc.: the Photo Electric Research Lab- oratory Corpo-rat'on, both of 723 Seventh avenue; and the Electrical Sound Institute, Inc., of Easton, Penn. The men named in the indictment are Fred A. Jewell, Lester A. Smith. G. C. Baxter Rowe and Eric E. Mackey. The corporations are said to have garnered over $200,000 from ambitious ap- plicants who have registered for courses in the institute in the hope of securing permanent em- ployment at a good salary. Complaints received from many victims of the scheme caused United States Attorney George Z. Medaile to order an investigation. His assistant. lent by Mr. Medalie. J. Hendrick Terry, spent six weeks on the case and finally presented it to the Grand Jury. The indictment charges that the defendants ad- vertisezd for men to operate a photo-electric en- graver, allegedly invented by Jewell, at a mini- mum salary of $50 a week. Applicants were informed that they must first pay $2 for an examination and then become mem- bers of the Sound Service Bureau. The mem- bership fee was $25. Only 1 per cent, of those fulfilling those requirements obtained passing mark in the examination and the rest were ad- vised to take a course in the institute. This course, which held out a guarantee of a $50 a week job or all money returned, cost from $85 to $150. Over 2.000 men, many of them practically destitute, enrolled for the course. Thus far, according to Mr. Medalie, no $30 a week jobs have materialized and there have been no refunds. The idea, he continued, was sold to the victims in the most highly colored fashion, the defendants holding out that Mr. Jewell's supposed invention, the photograver, would soon establish a world monopoly and that the various affiliated corporations, of which the defendants held all offices, would grow rich and powerful. Some forty branch offices have been established in as many cities all over the country and high pressure salesmen have been engaged to secure students on a 50 per cent, commission basis. The claims made for Mr. Jewell's new process, which is not patented, were said to be false and fraudu- lent by Mr. Medalie. [From New York Sun] ■WWI— Wlllll— 1— ■■— November 1931 INTERNATIONAL PROJECTIONIST 29 made from the process. We reproduce herein excerpts from this article. Get a load of this: Customers are clamoring for Photo Gravers. Thousands of them must be built and assembled. Scores of men must be immediately emp oyed. Thousands of men must be immediately p aced in training and thousands of new members must be secured for National Sound Service Bureau, Inc. — and this must be done with the least pos- sible delay. SUCCESS is ours now but it is only the beginning of such a TREMENDOUS success, that we can't realize it or believe it. To sum this whole thing up and to conclu le this story, you fellows, who are out there in the field privileged to serve in your present capacitie.s, are LUCKY. There are going to be more ten and fifteen and twenty and twenty-five thousand — ^yes — and even fifty thousand dollar a year jobs with our asso- ciated corporations, than there are warts on a frog's er - rear end, and some of you fellows who are reading this now, are going to be in these jobs. All of you who are reading it have a chance for them. We have been and are going to continue to grow faster than any other corporation in Amer- ica. We are going to get so doggone big and have so damn much money that the United States Gov- ernment is going to have to build new mints, and we are going to have to open up our own banks just to have a place to keep the money — the ones they have now are not big enough. No matter how wild a dreamer you are, or how vivid your imagination is, or how many shots in the arm you can take, you can't realize what a chance you have here. Our big jobs are going to be filled from the ranks of the men holding the little ones now, and if you are anything more than the dumbest guy in the world, you want to get sold on that idea and then go out and sell the world on it — for the world is our meat and we are sitting on top of it and we have got it by the tail. So get your coat off — give us every ounce of "guts," brains and energy that you have, and if you can find any place that you can use them that will bring you bigger, quicker returns, I am a cock- eyed hump-backed Chinaman. So let's go — let's hit that old ball— let's triple the pace and boy, oh boy, we will start believing in Santa Claus again— we will begin to pity Rockefeller's pov- erty and you'll know that God is in his old Heaven and there are more blessings there than there are brickbats in hell — so altogether now — HEADS UP' CHIN OUT FORWARD HO — WE'RE OFF!! Not bad, this. What we can't under- stand is how any man who knows any- thing at all about the electro-technical arts (projectionists qualify), shouldn't grab this opportunity to make a few ex- tra cookies for the wife and kiddies. We ourselves are tempted to enroll — AT ONCE! The only thing that is holding us back is the possession of a reference^ bearing on a similar process which is only forty-seven years old. This refer- ence fills us with strange misgivings as to why some other bright person hasn't followed-through on the idea set forth therein. It is immaterial for the purpose of this story to discuss the merits of this "new" engraver. This story is intended to place before the readers of International Projectionist all the available facts re- From I. A, General Bulletin JMo. 256 FOLLOWING is a most interesting report filed by the National Better Business Bureau, Inc., of New York, which organization made a thorough investigation of the Projectionist Sound Institute, located at Easton, Pa., and which reveals the inconsistency of the promises and guarantees offered prospective students to secure their enrollment: Numerous inquiries have been received concerning the Projectionist Sound Insttute which is engaged in selling a correspondence course in motion picture sound engineering. The principal of the enterprise appears to be F. A. Jewell. The price of the courses sold by the institution varies. The course itself is said to consist of approximately 52 lessons and to requ're an average of one year for completion. The institute was founded on or about September 1, 1929, according to Mr. Jewell. Some months ago we asked Mr. Jewell for certain information which we considered important for the purpose of answering inquiries competently. We wanted to know how many students were enrolled in the institute, and were informed: "We consider this a personal question and refuse to answer, although we might state that our enrollment is in the hundreds." Asked the number of instructors, Mr. Jewell replied : "This is rather an indefinite question and can only be answered in a general manner. Our answer is: A sufficient number of instructors to adequately instruct the number of students we have enrolled." Advertising for Projectionist Sound Institute has stated that there are "thousands of positions open right now for motion picture sound engineers," has supplemented this with numerical esti- mates, and has made other allegations regarding the high salaries paid. In order to obtain what we considered the most competent advice on these subjects, the Bureau consulted the I. A. T. S. E. and M. P. M. O. U. and another authority constituted to represent the producer and theatre owner. Estimates given by these authorities, both as to number of positions open and salaries ordinarily paid were emphatically more conservative than those advertised by the institute. Mr. Jewell was sent this information and his attention was called to the trade practice conference rules adopted by correspondence schools and the Federal Trade Commission. He com- mented on them as follows: "We wish to advise you that what you sent us was a Code of Ethics approved by the Federal Trade Commission and is nothing more than just what the name implies — 'Code of Ethics,' and not rules or laws. We have legal counsel to whom we pay good money to keep us informed on the legal phase of all our business transactions and we govern ourselves accordingly." The Projectionist Sound Institute has featured a guarantee to secure employment for any student "providing you will maintain an average of 80 per cent or better in your studies." During April, 1930, a Cleveland resident received a letter from Projectionist Sound Institute, signed W. F. Brittain, part of which read as follows: "Mr. Lester Al Smith, who is a representative of one of the largest sound equipment manu- facturing corporations in the world, has prevailed upon Mr. F. A. Jewell, who is one of the fore- most authorities on Sound Projection in the country, and General Manager of the Projectionist Sound Institute, to turn over the facilities of the institute and assist him in selecting a number of men who can be trained to take care of the persistent demand and the vast expansion that his company anticipates." Subsequently the prospect received a telegram from Mr. Smith urging him to make an appoint- ment. The Cleveland Better Business Bureau reported that Mr. Smith represented himself as being from a certain sound equipment manufacturing company located in New York City and that he told the prospect that upon completing the correspondence course he would be sent to the company named for two weeks' intensive training. We called this to the attention of an official of the company named and were informed that Lester Al Smith was in no way connected with them and that they had no arrangement with Projectionist Sound Institute whereby its graduates would be sent to the company for training. More recently the institute's literature has represented that, through a tie-up with National Sound Service Bureau and Photo-Electric Research Laboratories, their students can earn while learning and gain practical experience. Letters from National Sound Service Bureau are signed L. A. Smith, Director of Organizations. This organization has informed us that they are an organ- ization of sound equipment and accessories manufacturers, users of sound equipment and sound engineers. We have not received any reply to a request for the names of some of these members. An individual has received a letter from this concern urging him to enroll in Projectionist Sound Institute, and containing the following paragraph: "If you will send us your enrollment fee for P. S. I., immediately taking advantage of the cash which would enable you to get the lessons as quickly as you could absorb them, we will guarantee to start you in a steady job with us within four months after receipt of your enrollment at a salary of $60.00 per week, but inasmuch as so much rests with you and the time you devote to your studies, we must reserve the right to have the P. S. I. refund your money in full if you do not make good on a job after a fair trial." Photo-Electric Research Laboratories is located at the same address as National Sound Service Bureau. A letter signed by Herbert Pratt, Director of Sales, tells us that his company is a mer- chandising organization employing students of Projectionist Sound Institute as agents on a strictly commission basis. The latest inducement offered by Projectionist Sound Institute that has come to our attention appears to be a "Special Cash Offer" whereby, although the regular price of the course is $120, prospects are told that $100 cash will be accepted in full payment and "This $100 we will reinvest in securing additional members, for which we will pay you 15 per cent of the gross amount received from the members that we secure from the use of your $100." By this system, the prospect is told, he may expect to obtain a return of his original $100 investment plus an additional $20. National Better Business Bureau, Inc. Commercial Department. ^ "iEIectrical Apparatus for Reproducing Draw- ings," by A. Schmid. Scientific American Sup- plement. Nov. 8, 1884, p. 7,371. lating to this particular enterprise. The wisdom of the International Alliance leaders in forbidding the participation of any I. A. member as a student in such '"schools" has been amply demonstrated. It seems a pity that some responsible 30 INTERNATIONAL PROJECTIONIST November 1931 FILM MUTILATION Abstracts from a report of the Projection Practice Committee of the S.M.P.E. THE Projection Practice Committee wishes to direct attention to what it considers one of the foremost causes of waste and monetary loss suffered by the motion picture industry, namely, the mu- tilation of positive prints. This mutila- tion not only results in a greatly short- ened life of the individual print, which is serious enough in itself, but in addition to this, it is impossible to obtain the maximum screen results, which are high- ly important in creating the proper illu- sion so necessary to the motion picture play. Both visual and sound results are affected by mutilation of film^ It is generally understood that the mu- tilation of film is frequently caused through the misadjustment of projector parts, worn projector p'arts, accumulation of emulsion during projection, excessive oiling of projector or oil leakage, and careless handling of film. The Projection Practice Committee is of the opinion that there is urgent need for the setting up of standards dealing with the various tensions the film should be subjected to during projection, the clearance of adjacent projector parts and The School 'Racket^ {Continued from preceding page) agency for the dissemination of reliable information anent such enterprises is not now functioning, as a prospective student now has no way of determining the worth, or lack of it, of any such set-up. International Projectionist purposes to delve deeply into this matter in an endeavor to supply its readers with infor- mation on all such enterprises. The latest "racket" is the television school, the propaganda of which invari- ably refers to television being "just around the corner." Projectionists are particularly easy marks for television schools, as there is a natural inclination on the part of the man in the projection room to fortify himself against any con- tingency. Already many projectionists are enrolled in television schools, and it is likely that there will be many more who will do likewise. International Projectionist has been offered the advertising of certain television schools but has declined, for the reason that it bears a very definite sense of obligation to its readers and will not be put in the position of seeming to endorse any such institution. It is a very difficult matter to establish whether a given school is worthy or not, and International Projectionist will not accept this responsibility by printing such advertising. sound apparatus, allowable tolerances, and the degree of wear projector parts may develop without impairing the qual- ity of screen results or causing mutilia- tion of film. The committee therefore plans to con- duct a thorough investigation which will be nationwide in scope with the view of obtaining all necessary data for submis- sion to the Society for the purpose of adopting such standards. In order to ac- complish this, the committee requests the earnest cooperation and support of the Society as a whole and also associ- ated individuals and organizations. Their assistance will be needed as this work will be of magnitude and should, when completed, prove invaluable to the industry. Non-Uniform Processing The committee wishes to call attention at this time to the lack of uniformity in the processing of prints, which consti- tutes another serious loss. In regard to the processing of film, there seems to be no standard for this work at the present time. One producer will use a certain method of processing film; another producer will simply wax the margins of the print, and a third producer will not process the print at all. This condition works a hardship on all concerned, inasmuch as it frequently hap- pens that the producer who has proc- essed his product suffers by reason of the theatre using unprocessed film at the same time. This evil adversely affects both the sound results and the visual picture. It is well known that with unprocessed film, there is a tendency to accumulate emulsion at the tension points in the pro- jector. Formation of emulsion greatly increases the tension applied to the film and imposes a serious strain on sprocket holes. Occasionally a positive print is irreparably damaged during its first pro- jection. To Investigate Methods The Projection Practice Committee recommends that thorough investigation to find the best method of methods of processing film be conducted by some designated committee of the Society so that such methods may be recommended as a standard for the industry. Unless such a standard is adopted, generally ac- cepted, and put into use hj the producers of film, the industry will continue to suf- fer this serious loss now occasioned through faulty (or the absence of ) , Drocessing methods and such benefits which should accrue through the adop- tion of the standards relating to pro- jector tensions, adjustments, etc., would be largely nullified. In the opinion of the Projection Prac- tice Committee, this work is one of the most important contributions that the Society could make to the industry. Committee Personnel: Projection Practice Committee: Harry Rubin, Chairman; Thad C. Barrows, G. C. inwards, Sam Glauber, J. H. Gold- berg, Chauncey Greene, Herbert Griffin, Jesse J. Hopkins, Lester Isaac, R. H. Mc- CuUough, P. A. McGuire, F. H. Rich- ardson, Max Ruben, H. B. Santee, L. M. Townsend. PROJECTIONIST RECALLS WORK WITH EDISON WHEN the lights in a Brooklyn the- atre flashed off on a recent eve- ning— as they did everywhere through- out the country in commemoration of their inventor's death — Louis A. Ham- mond, chief projectionist, peered into the darkness and let unfold from the cinema of his memory his own association with the great Edison. There flashed into mind a day 16 years ago when Hammond was chosen from 21 motion picture "operators" to be Edison's assistant in perfecting the synchroniza- tion of phonographic recording with mo- tion pictures; chosen, he says modestly, because he "was not afraid to get his hands dirty." That was in October, 1912, at the lab- oratories in New Jersey. Less than a year after getting the impressive title of "Chief Operator of Kinetescope and Kinetephone," Hammond was sent to Eu- rope. The "Hoch Geschenck" Among the notables before whom En- gineer Hammond demonstrated his 12- reel novelty was the Emperor Franz Josef of Austria, who was then 83. The Em- perior was so pleased with the perform- ance that he gave Hammond a "double- decker" gold watch, which was the "hoch geschenck," or highest gift, the Emperor could bestow upon a commoner. "We gave an exhibit in the castle of the Grand Duke and the Duchess of Mecklenberg, and the following night the ancient fortress was burned to the ground. The peasants of the section firmly believe the fire was started from the kinetoscope's celluloid reels and looked upon us as incendiaries." Investigation proved the fire started in another part of the building from that in which the apparatus was stored and the Hammond party was exonerated. Their machine and the films were destroyed in the fire. This accident did not, however, end Hammond's association with Edison, for he returned to America and, as he says, "puttered around the Edison Laboratory for more than a year," after which he was detailed to the San Francisco Expo- sition. November 1931 INTERNATIONAL PROJECTIONIST 31 TELEVISION NEWS NOTES NBC Heads Sees Speedy Television Development ME. AYLESWORTH, president of • National Broadcasting Company, maintains that television will develop more rapidly than sound broadcasting because it enjoys the benefit of modern research and engineering methods and facilities, as well as the support of the older broadcasting institution. The NBC executive predicts that with tele- vision continued as a supplement to ex- isting sound broadcasting, no serious artistic problems are anticipated. When the time arrives that a picture can be transmitted in clear relief, television will be the main issue and sound the supple- ment. Sports events, parades, cere- monies, plays, pageants and many other subjects can be presented to better ad- vantage than in sound. Mr. Aylesworth further contends that the immediate application of television is the visual presentation of the broad- cast artist. On one set the auditor will hear the song, the speech or the music, and on another set he will see the artist. Channel Requirments of Good Television IN televising by radio, the limits are a single channel, and therefore, a single section picture, which could not be projected advantageously upon a mo- tion picture screen. Distant points that can be reached are also very restricted. Even such favorable conditions as will prevail in the instance of the radio vision broadcasts that will soon emanate from the Empire State Building will hardly be heard and seen clearly beyond a 20- mile radius, despite the many objec- tionable interferences removed because of the height of the sending station. With such outstanding restrictions, the adaptability of radio televising is auto- matically confined to motion picture the- atres in larger cities until a longer air- wave can be found to bring quality pro- grams to theatres spread throughout the country. In addition, the problem of fading of air transmissions, a puzzle which has not as yet been solved even for the scientifically-built radio sets of today, will have to come in for serious consideration. Difficult Task to "Sell" Television to Public WHILE due credit should be given the organizations now actively pioneering in the television market in its infancy, there is no doubt that the wide- spread introduction of television as a household item awaits the cooperation and use of the vast resources and facili- ties in back of existing radio and broad- casting systems. The tendency on the part of the larger organizations now working with radio is to maintain a secrecy as to their plans for television. It is generally known, however, that their laboratories are actively engaged in tele- vision research, in an effort to produce dependable television products that will put the art into the home on a firm basis. Much of the interest in television has come from the suggested similarity be- tween the popular science of radio and television. Television has without much effort mustered together an army of en- thusiasts from among radio fans, but to "sell" television to the public in general, and enlarge the field to its true possibili- ties, will undoubtedly require an enor- mous amount of advertising and far- reaching tie-ups between the closely in- ter-related organizations that now cater to radio. Interesting Apparatus of Insuline Corp. THE apparatus shown in the accom- panying illustration is the televisor designed by the Insuline Corp. of Amer- ica to project television between two points connected by wire as transmitted by a single adaptation of a motion pic- ture projector incorporating standard 35 mm. safety film. The transmitter may also be operated in conjunction with a radio transmitter, the picture modulated energy output being used to modulate the carrier-wave in the usual manner. The method of scanning employed in the transmitter is worthy of special at- tention. The 16-inch aluminum scan- ning disc has the holes arranged in a circle for film-picture projection; hori- zontal scanning, from left to right, is thus accomplished; while the vertical scanning is obtained by the continuous motion of the film in the projector. Use 24-HoZe Disc The speed of the film downward through the projector must, therefore, bear a definite relation to the speed of the scanning disc. Each "frame" must be scanned from left to right 48 times. Instead of having 48 holes in the disc and revolving it once for each "frame," we have a 24-hole disc and revolve it twice as fast. For a given size of pro- jected picture, this permits the use of a smaller disc than would be necessary if 48 holes were employed. The photo-electric cell used in con- junction with the transmitter is of suf- ficient sensitivity to permit its use with a minimum amount of amplification, thus assuring frequency response and a low level of tube and battery noises. Light to actuate the photo-electric cell is ob- tained from a 500-watt, special ribbon filament Mazda stereopticon lamp. A special optical system of lenses and con- cave mirrors concentrates the light with but slight loss, onto the film. A con- densing lens focuses the scanned di- INSULINE TELEVISION TRANSMITTER Front view of transmitter: A, reduction gear driven from rear end of motor shaft; B, reel housing; C, exciter lamp; D, circle-scanner; E, lens (without mask) ; F, photoelectric cell; G, Television-frequency amplifier; H, phase reverser 32 INTERNATIONAL PROJECTIONIST November 1931 verging rays, coming through the scan- ing disc, onto the photo-electric cell. Rotation of the transmitting scanner is obtained by mounting it directly on the shaft of a 1/10-h.p. synchronous mo- tor, rotating at 1800 r.p.m. The film is driven by this motor, being connected to it by an eight-to-one reduction gear, thus moving the film at the rate of 15 "frames" per second. A unique "phase shifter" is also pro- vided to enable positive or negative film to be televised. In this manner, the use of either kind of film is permitted with- out necessitating the addition or re- moval of a step of amplification. New Cathode Ray Tube Great Aid to Art TELEVISION is expected to take a big step forward with the perfection of the cathode ray tube. The cathode ray tube looks very much like a cone- shaped vacuum bottle, on the flat end of which, on a flourescent screen, images are formed. The images obtainable with the cathode ray tube are considered to be far superior to those produced by scanners or neon tubes. At the same time, the cathode tube can copy a greater number of lines than do the scanners or neon tubes. In speaking of cathode ray tubes, San- abria, the 25-year-old television worker who "stole the show" at the recent Radio World's Fair held in New York by tele- vising the largest images so far offered the public, says: "The mechanical method seems best if a large image is de- sired. The scanning disc and its asso- ciated devices are much less complicated than electrical scanning, which calls for expensive and complex apparatus. How- ever, progress is being made with the cathode ray scanner and it shows prom- ise for the future." The cathode ray accomplishes its work by employing elements which bend the electronic stream back and forth and gives the same effect as scanning. The cathode ray cannot, however, be incor- The New Yark Television Demanstration THE recent television demonstration by U. A. Sanabria, 26-year-old Chicago "wizard," at the Broadway Theatre in New York City, has set to wagging the tongues which for several years past have been predicting "television just around the corner." Many of our readers have expressed interest in this demonstration and have inquired as to its significance. The answer is that the demonstration is significant only in that it generated not a little worthwhile interest in the tele- vision art — and that is all. Technically, the week's run was just so so. It would be idle to deny that much progress has been made and is daily being made in the television art. But just at present there is nothing to indicate that television will soon enjoy any great degree of popularity. Its use in the theatre still is a matter of years and not days, weeks, or months, as is predicted by many television promoters. The Sanabria demonstration was nothing more or less than conventional. True, he did produce a 9-foot picture but only at a great sacrifice of detail. We saw the picture and it wasn't any great shakes. We haven't seen a larger picture anywhere, but we have seen much better quality — which, after all, is what counts. The Sanabria picture required much squinting and peering to distinguish the image, and it proved a dull show to us. That which Sanabria gave us at the Broadway could have been done by any number of television workers. Jenkins, Western Elec- tric, Radio Corporation of America and one or two others we could mention could have done as well, if not better. The answer to the question of "Why don't they?" is that these companies are working for quality images and not quantity. Mr. Sanabria got his 9-foot picture all right, but in so doing he sacrificed quality — that is, the sort of quality to which we are accustomed. The best television we have seen thus far has been that of Bell Telephone Laboratories, and this particular system, according to the Laboratories' own admission, is far from being a commercial possi- bility. We had a "commercial" television set in our home for several weeks, but the images were so poor that we gladly loaned the set to a friend and were glad to be rid of it. To those projectionists who are anxious about the early arrival of television in the theatre we say "Forget it." It is all very well to maintain a lively interest in the progress of the art, but getting ex- cited about "television just around the corner" is a waste of energy. There is nothing to it. JAMES J. FINN porated in the ordinary receiver without the use of special equipment that will allow but an extremely small amount of current to pass at a high voltage. Suggests Multi-Screen for Four Televised Images WRITING in the current issue of Television News, C. Maggi sug- gests a multi-screen receiver that will, by projecting images on four sides of the cabinet, permit observers to see tele- vision images not only from the single position straight in line with the lens, but from four (or more), angles. The essential parts needed to build a multi- screen receiver are: four scanning discs, four neon tubes, four screen assemblies, one upright motor, and five gears. In assembling the multi-screen re- ceiver, the motor is mounted to the base- board. The master gear is mounted at the end of the motor shaft, and four gears are mounted about the master gear (90 degrees from each other) with a 14- inch shaft 7 inches long. One end of the shaft goes to the scanning disc and the other to the scanning gear, which is revolved by the master gear. The four scanning shafts are supported by a four- sided frame, with its associated collars, etc. Complete details and drawings for building the multi-screen receiver are contained in the Maggi article, which is recommended to television "fans." VACUUM TUBE PRODUCTION The production of a vacuum tube parallels a tremendous industrial task, in miniature. Aside from the numerous fine elements used in the construction of a tube which could be termed analagous to minute girders, braces, cross-members, etc., there are 186 various spot welds in the final assembly of the elements. This is equivalent to the number of welds required in laying a %-mile pipe line, with each section of pipe 20 feet long. This would be sufficient to weld all steam and water pipe connections in the average home; or, in the marine field, to weld a mammoth anchor chain 93 feet long for one of the big ocean liners. In aviation, a complete plane including the frame and fuselage could be securely welded with this large number of oper- ations. It is hardly believable that this great number of welds are necessary in a small article like a vacuum tube. But fine wire and small parts are used which re- quire a weld no larger than a pin-head. H. & C. NEW H.-I. LAMP Hall & Connolly, Inc., have developed a new and radically different high inten- sity projection lamp for amperages from 75 to 200, the result of intensive research for more than a year. The design lor the lamp includes a number of new principles that will appreciably improve projection and facilitate operation. Z/A^ PATENT PAGE THE following digest of patents granted recently was prepared ex- clusively for International Pro- jectionist by Henry L. Burkitt. Mr. Burkitt, B.S. in ch. e., L.L.B., is a former Assistant Examiner in the U. S. Patent Office, a member of the Bars of New York, Pennsylvania, and the Dis- trict of Columbia, practicing in New York City. Any reader desiring infor- mation on any patent, whether abstracted herein or not, should address Mr. Burkitt in care of this publication. — Editor. Granted September 8, 1931: Film Projector 1,821,930. Cinematographic Projec- tor, to Maurice Couade. The film guide of this patent apparently is associated directly with means for advancing the film intermittently. A member, which recipro- cates both in the same line as the film moves, and toward and away from the film, has a claw in- tended to be projected through the guide to en- gage the film and move along with it, and then to be withdrawn from the film. An eccentric pin produces the two reciprocatory movements of the claw member. Film Mechanism 1,821,946. Motion Picture Apparatus, to Freeman Owens. A motion picture projector, using sound film, has a shutter shaft with a combined drive wheel and shutter afExed adjacent to its end. A fric- tional device engages the drive wheel to trans- mit power to the shutter and to the mechanism for intermittently moving the film. A finger wheel at the end of the shaft opposite the drive wheel provides means for rotating the shaft. Novel Recorder 1,822,057. Method for Recording Pho- tographic Sound Records, to Freeman H. Owens. The invention is concerned with the consolida- tion, upon a single film, of the musical or other sound effects recorded individually upon a plurality of films. The electrical impulses, created by a number of such films, are used conjointly and simultaneously to modulate the intensity of a light producing element. The varying light from this element is then used for recording on the single film. Plurality of Lenses 1,822,528. Moving Lens Cinemato- graph Machine to Wesley Ernest John. A number of lenses are moved past a point at which they are exposed. The lenses are arranged to move along straight and curved paths, these paths communicating so as to form a continuous path. Recording Light Source 1,822,865. Method and Apparatus for Producing Photographic Records, to T. W. Case. , . . not "clips^^ in wordy patent language but clear and concise abstracts prepared especially to meet the needs of readers of this publication. sound films. Its particu'ar structure would prob- ably be interesting only to those working in this highly specialized field. New Perforating System 1,822,350. Arrangement of Perfora- tions Cinematographic Films, to Julien Henri Jarnier. The film of this system has its perforations be- tween the images, rather than along the sides, as is customary in America. The number of per- forations is determined according to a formula in which the number is made directly proportional to the width of the film, and to a factor called the specific resistance to rupture by traction, and inversely proportional to the difference between the resistance to rupture of the width of a per- foration and the product of that width and the specific resistance to rupture. Lens Shifting Device 1,822,551. Lens Shifting Mechanism for Projecting Machines, to Albert Tond- reau; assigned to Warner Bros. Pictures, Inc. This patent relates to a means for positioning one of a number of lenses with relation to a motion head. The arrangement of the lens shells permits longitudinal adjustment of the shells with relation to each other. A pivotal connection permits any one of the shells to be positioned with its axis in alignment with the projected light. The lens shifter handle is provided with suitable stops for defining its movement. Film Control 1,822,727. Film Phonograph, to Guil- lermo A. del Valle; assigned to General Electric Company. In connection with a sound record made on a film, means are provided at the end of the sound track to be engaged by a member normally out of engagement, but moving into engagement with the film when the roll of film has decreased to a predetermined diameter. This means could be used for stopping the motor or for any other purpose. Granted September 15: Film Winding Device 1,823,245. Motion Picture Film Wind- ing Device, to Otto Wittel; assigned to Eastman Kohak Company. The patent is for a light source used in makng This winding device includes a flange ani a [33] Edited by H.L.BurKitt pair of hubs, one of which is slidably carried by the flange. The hub members are separable by sliding the flange on one of them. Tinting Sound Film 1,823,246. Method of Tinting Films for Use in Sound Reproduction, to Al- bert A. Young; assigned to Eastman Kodak Company. The sound track portion of the film is pre- served untinted while the remainder is retained against shrinkage. A dye, dissolved in a medium consisiting of two solvents, one both for the film and for the dye, and the other not dissolving the film. The latter acts to reduce the evaporation rate of the entire solvent, and thereby reduces the tendency of the film to buckle. Modifying Sound Negative 1,823,349. Sound Picture System, to Shelby C. Chapman; assigned to Elec- trical Research Products, Inc. The patent is for a method of modifying the negative of a sound film and involves chemical reduction of the sound record, progressively vary- ing lengthwise of the film. Framing Device 1,823,355. Telescope Framing Device, to Louis Simon Frappier and Ewald Boecking; assigned to International Pro- jector Corporation. A microscopic adjustment is provided for light directed upon sound film. The microscope used for this adjustment is supported in a housing at an aperture, adjacent which is located a prism supporting means for changing the angle of the scanning light. The housing may be mounted upon the film gate support in interchangeable re- lation with the film gate itself. Novel Speaker Diaphragm 1,823,512. Loud Speaker, to Abraham Ringel; assigned to Radio Corporation of America. A loud speaker includes a diaphragm so small that it would not normally reproduce low fre- ■ - "• notes A method is involved in which a diaphragm of this character is used and the movement of the driving member for the dia- phragm 1-- steppeJ up sufficiently to reproduce the desired low notes. Disc Reproducer 1,823,737. Motion Picture-Sound Ap- paratus, to Charles L. Heisler; assigned to General Electric Company. This projector includes a phonograph turn- table, mounted on the same base with the pro- jector and having separate adjustment on a com- mon axis. A motor is provided and has a drive connection with the turntable. Granted September 22: Film Matching Means 1,824,294. Sound and Picture Film Matching Means, to Freeman H. Owens; assigned to Owens Development Corpora- tion. Sound film, to be used for reproduction syn- chronously with a separate picture film, has on a 34 portion thereof parts of the picture film so that the operator will be enabled to match the two films in reproduction. Multi-Element Screen 1,824,353. Screen for Shoiving Pro- jected Images in Lighted Rooms and for Short-Exposure Photography, to Rasmus Olaf Jonas Jensen. A screen consists of a member of light re- fracting material, one surface of which presents to the image source a multiplicity of lenticular elements. Each of the elements focuses upon its opposite surface the light received. This surface is translucent only at these foci and is light absorbent at all other points. Color Photography 1,824,446. Method of and Apparatus for Producing Motion Pictures in Color, to Edwin L. Pearson. A projection machine produces colored motion pictures by successively projecting images through different color filters, the colored images being projected upon a screen having various colored sections corresponding to the filters. The rela- tive positions of projector and screen are shifted to project images successively upon portions of the screen corresponding to the particular filters through which particular images were produced. Photo-Electric Cell 1,824,573. Photo-Electric Tube, to Fritz Schroter; assigned to Gesellschaft fiir Drahtlose Telegraphic m. b. H. This photo-electric cell has a light sensitive cathode formed of an alkali metal to which a very small portion of caesium has been added to accentuate the photo-electric effect and to raise the critical potential at which glow discharge starts. September 29, 1931: Film Magazine 1,825,142. Motion Picture Film Maga- zine, to William A. Bruno; assigned to Clarence W. Fuller. The drive for the film is constituted by a film reel having a plurality of spaced openings on the film carrying surface. A propelling drum is mounted within the reel and has a plurality of teeth which simultaneously engage in the open- ings in the reel and the openings in the film carried by the reel. Overlapping Film Reel 1,825,438, 1,825,439 and 1,825,440. Photo Sound Recording or Reproducing, and Sound Recording or Reproducing Apparatus, to Aloysius J. Cawley; as- signed to Radio Corporation of America. These patents relate to sound film. A reel carries the film with the sound records at its edge. The wheel is on such extent that the sound extends beyond the edge of the wheel to permit proper transmission of light therethrough. Driving Mechanism 1,825,442. Driving Device Employing Maltese Cross Wheels, to Marius Cham- bon; assigned to Etablissements L. Chambon. The mechanical movement in this patent for securing intermittent motion has a Geneva gear mounted on the driven shaft, and a plate on the drive shaft. The plate has a sliding member carrying a roller engaging the Geneva gear, and a cam, parallel to the plate, is engaged by an- other roller on the member. INTERNATIONAL PROJECTIONIST Granted October 6: Keel and Spindle 1,825,663. Film Reel and Spindle, to Arthur C. Hay den. The reel is made up of a pair of plates, held separated by a hub on which the film is wound. Both plates have openings formed therethrough, and one of them has tongues projecting into its opening to cooperate with a groove in a spindle extending through both openings to prevent movement of the reel axially of the sp'ndle. Color Photography 1,825,863. Color Photography, to Joseph B. Harris, Jr. The invention relates to the production of color potographs by first forming images on a layer of ligth sensitive material carried by a transparent member. Images are formed on the two faces of the material, that is, the exposed face and the face adjacent the transparent carrier. Then the outside image is developed and toned with ferric (compound of iron), salts after which this image is resensitized. Then the other image is developed and toned. Continuous Projection 1,825,953. Device for Permitting the Continuous Feeding of the Film in Pro- jecting Apparatus, to Per Georg Halvar Hallongren. The apparatus is for projecting moving pictures without the customary intermittent stopping of the film. Two sets of mirrors are arranged radially upon two separate axes. These sets are rotated synchronously in the same direction. The reflecting surfaces in each group face in the same peripheral direction. The reflecting surfaces of one group face in the direction of rotation, while the reflecting surfaces of the other group face in the opposite direction. Light striking a mir- ror of one group is reflected to a mirror in the second group, provided, of course, the mirrors are in position. Since mirrors are continuously rotating as the film moves, the same interruption occurs as with a shutter and an intermittingly moving film. Color Process 1,826,001. Color Photography to John Naish Goldsmith and Thomas Thome Baker; assigned to Spicers, Ltd. The film consists of a cellulose derivative, the film base, first coated with a material reacting against the penetration of dye solutions and dis- charging agents into the base. A layer, which will take dyes and discharging agents, is applied then. Finally, a multicolor screen is applied. The essential conditions for producing pictures in stereo- scopic relief are two: first, sepa- rate pictures must be made from different points of view, corres- ponding to the two eyes ; second, each eye of the observer must receive its appropriate view. No compromise with these fun- damental requirements appears possible. Dr. Herbert E. Ives Director, Electro-Optical Research Bell Telephone Laboratories November 1931 Plurality of Cells 1,826,522. Apparatus and Method for Reproducing Photographic Sound Rec- ords, to Freeman H. Owens; assigned to Owens Development Corporation. Light from the light source is directed through a sound film and impinges either upon a light cell, immediately aligned with the film and the- light source, or upon mirrors or like light di- verting means directing the rays upon one or more other light cells. All of the impulses in the individual light calls are jointly amplified and rendered audible. Granted October 13: Sound Picture "Stills" 1,826,786. Method and Apparatus for Reproducing Sound in Connection With Pictures, to Philip S. Hopkins; assigned to Agfa Ansco Corporation. The apparatus of this patent is designed to co- ordinate the use of a sound film with "still" pictures, that is, the mechanism coordinates the showing of such pictures with the reproduct'on of appropriate parts of a sound record. Film Printer 1,826,858. Photographic Printing Ap- paratus, to Vladimir K. Zworykin; as- signed to Westinghouse Electric and Manufacturing Co. The apparatus is designed for transposing the record of one film upon another film, and ap- parently is intended to produce a picture of a different size or having different characteristics than the old film. The driving mechanism for the two films ave different effective speed producing portions. The driving portion for one film is within the driving portion for the other film, and light from the negative is transmitted through the space between the two driving portions. Fire Preventive 1,827,010. Film Flame Stop, to Law- rence D. Kohlmeyer. A frame is provided carrying a number of roll- ers, other frames being mounted to permit the rollers, by gravity, to swing downwardly toward, and to be stopped tangentially against, others of the rollers, apparently to grip and stop the film and to retain it against feeding where a fire has started and also to prevent burning back. Film Drive 1,827,588. Film Drive, to Edward W. Kellogg; assigned to General Electric Co. The film is driven by a sprocket and a drum, , and means are provided, responsive to difference in speed of the portions of film moved by the respective sprocket and drum members, as de- termined by the number of sprocket teeth open- ings, and independently of the length of film between the members. Screen Cabinet ^ 1,827,598. ♦ Moving Picture Cabinet, to Arthur Merriman. This patent is curious merely in that it in- cludes, with a cabinet designed to direct a cine- matic beam outwardly through an opening in one of its walls, a screen external of the housng and supported upon a framework so that both frame- work and screen may be folded into a substantial- ly horizontal plane and slid into a compartment in the cabinet. 1,820,054. Light Guard for Motion Projector Light Guard * Picture Projection Machines, to Augusta- Dina; assigned to International Projec- tor Corporation. The apparatus of this patent is to limit the area of the light beam falling upon the sound •JJOEJl November 1931 INTERNATIONAL PROJECTIONIST 35 GOLDE 3-ALARM A VALUABLE PROJECTION AID DESPITE the adoption of the Stand- ard Release Print, with its uniform ■cue and footage markings, there still are projectionists who find it necessary to add their own cues to the film. The S'.R.P. was designed to eliminate such marking, and it cannot be denied that the trouble from this source has been reduced. However, the presence on film of individual markings — foil contacts, scratches, punchings, chalk marks, clicker patches, and even scraped frames — shows that the S.R.P. did not solve the <;hange-over problem for projectionists. It is generally held that the principal xeason for adding extraneous markings to film is fear — fear that the dots have teen missed or that some unforseen de- velopment will arise just before the cue markings appear. This anxiety on the part of the projectionist to maintain per- fect continuity causes him to introduce visible or audible signals — which help him but greatly distract the audience. Patrons resent such interruptions, and their resentment is reflected at the box •office. Aside from the human equation al- ready mentioned, there is the matter of variation in motor speed to be considered. Some projectors require several seconds more than others to come up to speed, and no standard markings can guide the projectionist as to when to start the in- coming projector. Then there is another angle and this the fact that projectionists cannot be "standardized": one man's re- flexes may be slower than those of an- other. There are also the censor's scis- sors which may have shortened the dis- tance between cue marks or eliminated them. To guard against such contingencies many projectionists place marks at vary- ing distances from the change-over cue. Such marks introduce another hazard, ioT the projectionist who receives a film Taearing the marks of five or six earlier showings, finds it almost impossible to pick out his own swiftly-moving marks, and is likely to come to the cue with a slow machine. Mutilation Rampant These are some of the things which theoretically should not affect operation Tjut which in practice often produce very lad results. Incidentally, it is a known fact that exchanges make a practice of shipping old and worn film to theatres which persistently return prints bearing damaging marks. This is done not in retaliation but as a matter of economy. To send a new unscratched print to such a theatre results in complaints from sub- sequent-run theatres. Projectionists should establishe a reputation at the ex- change for careful film handling, as this -will insure receipt of better prints. Throughout this country there are many personally made devices for giving a change-over warning, but without ex- ception such devices scratch or wear the film. If these devices were replaced by one which causes no abrasion of film and at the same time renders all markings un- NOTES from the SUPPLY FIELD * necessary (even to the extent of reduc- ing the size and number of S.R.P. mark- ings), great benefit would accrue to the projectionist as an individual and to the exhibition end of the industry. Plainly, what is needed is a device that will tell the projectionist when to illumi- nate his arc, when to start his motor, and when to throw his change-over shutter. These three signals must be given in a manner that the projectionist cannot miss or mistake, no matter what may tend to distract him, and in a manner that will not distract the audience. The signals must be so timed as to suit the accelera- tion of the machine and provide for the reactions of the individual projectionist. Solving the Problem A device that meets all these require- ments has recently been adopted by some of the country's leading theatres, and long tests therein have proven its worth and given indication that its use will soon be widespread in those theatres who de- The GoldE 3-Alarm sire flawless projection. This device is the GoldE 3-Alarm. As is shown in the accompanying il- lustration, this device has three arms piv- oted at one end, the free ends each car- rying a roller. The pivot is mounted on the movable end of a bearing plate, which is also pivoted. The movement of this bearing plate is limited by a spring locking pin. The bearing plate pivot is held by a base plate securely fastened to the wall of the magazine. The roller on the free end of each arm may be micro- metrically adjusted to greater or less dis- tance from the pivot — in effect, shorten- ing or lengthening the arm. This adjust- ment may be permanently set by means of a nut lock. The rollers ride on the diminishing roll of film in the upper magazine. One arm is adjusted to fall off the roll when it has so diminished that the change-over cue is one minute away. The second arm falls at a time determined by the pro- jectionist but far enough ahead of the change-over cue to allow him to bring his incoming machine up to speed. The third arm falls as the change-over cue arrives on the screen. As each arm falls it clicks against the magazine, giving a sound that is clearly audible above the whirring of the projector but which can- not be heard outside the projection room. Thus the projectionist is not required to watch the screen — his eyes can aid his hands in making a smooth change, and no signals are necessary in either the frame or sound track. The audience is, of course, wholly unaware of the change. Projectionists reading this will imme- diately reason that, to operate the GoldE 3-Alarm successfully, reel hub di- ameters must be exactly uniform. That thought is correct. Two diameters are in general use: 5-in. and that of 2-in. Mention was previously made of a piv- oted bearing plate limited in its move- ment. The inner limit of this plate ad- justs all three arms of the 3-Alarm for a 2-inch hub; the outer limit sets them for a 5-inch hub. Thus the two standard hub diameters are provided for. There are off-standard hubs, of course, but these are in the minority. They may be used, however, by employing a method of building up the hubs to standard di- ameter which has been developed by for use with the 3-Alarm: to discover off- standard hubs, cut a length of film the ends of which will exactly butt together when it is wrapped once around a stand- ard hub and test all hubs with this. Varying Terminal Lengths It will also be discovered that to make the 3-Alarm practicable, the dis- tance from change-over cue to the end of the film must be alike in all reels. A check of more than 100 reels as they were shipped from exchange has shown that the number of reels in which this distance is incorrect is so small as to be negligible. Those that do vary are sel- dom more than 1 or 2 feet, which is well within the limit which makes the 3- Alarm accurate. The rare cases of ex- ceptional variation in either shortness or 36 INTERNATIONAL PROJECTIONIST November 1931 length are easily detected. As every pro- jectionist inspects all film on its arrival from the exchange, a very simple check for length may he made at that time. With the film reversed on the rewind, strip off as far as the change-over cue (or the end of the action). Then count the number of turns of the rewind handle from the cue to the end of the film. If the variation is 1 turn, or a fraction thereof, the performance of the 3-Alarm will be accurate. If variations of greater than Y2 turn either way are found, cut- ting or patching the tail end will equal- ize them. When the 3-Alarm method of change- over preparation has become general, it is likely that producers and exchanges will provide all prints with standard terminal lengths. It is to be expected that such action will not be delayed, as the GoldE 3-Alarm appears to supply the answer to a positive, complete and inex- pensive change-over signal. NEW G.E. THYRATRON THEATRE LIGHTING CONTROL- THYRATRON tubes are the basis of the new G.E. lighting control scheme. By shifting the phase relation- ship between the elements in the tube, the average amount of rectified current passed by the tubes is varied, governing the intensity of the lights. By splitting the lights into various circuits, various groups can be controlled individually, and related groups of circuits can be controlled collectively through master circuits. This lighting control scheme eliminates the bulky back-stage switch- board and makes the manipulation of the control a matter of extreme simplic- ity. A modified form was installed in the new Earl Carroll Theatre in New York, just opened; and RKO, in addition to a new Schenectady theatre, will in- stall the system in new theatres in Al- bany, N. Y., and Denver, Col. The new Schenectady theatre, being designed for the production of motion pictures only, has but 10 major lighting circuits, 6 on the stage and 4 in the auditorium. The stage lights are di- vided into three colors: white, red and blue, with one control for each color in the footlights and borders. In the au- ditorium but one color is used, with a circuit control for the fixtures, two for the ceiling and another for the niches and receptacles. A novel addition to the lighting scheme is a "panic" control by means of which the full brilliance of all the lights in the theatre can be turned on instantly by the flick of a single switch, no matter what complex lighting . effects might be in progress at the time. SPECIAL W.E. EQUIPMENT FOR STAGE PLAY ANOTHER innovation for legitimate stage productions has been contrib- uted by Electrical Research Products, Inc., with the opening in New York of "Hamlet." Shakespeare's century-old lines will be enhanced by modern science in the form of music and sound effects coming from the loud speakers of a W. E. music reproduction system. Discs Lose Favor The rapid decline of discs as ac- cessories of sound reproduction in the theatre is emphasized by a re- cent survey of Western Electric domestic installations. Of a total of 5,300 such installations there are only 5 equipments which han- de discs only. These equipments which are capable of handling only sound-on-firm number 1,500; with the balance of 3,795 equip- ments able to handle either disc or sound-on-film transcriptions. These figures provide an inter- esting sidelight on the progress made in the art since the first sound picture was exhibited in 1926. Economic considerations are reported to have played the leading role in the displacement of disc recordings by sound-on-film, inasmuch as many experts in sound recording maintain that discs afford a better quality of record- ing and reproduction. Special recordings have been made of a type similar to those used for elec- trical transcription programs broadcast over the radio. Twin turntables, operat- ing at 33 1/3 revolutions per minute, are so arranged that there is no pause in switching from one record to the next, and also provide for superimposing one sound effect upon another. This super- imposing facility is used to particularly marked advantage in the ghost scene, during which the weird sound of the wind at midnight continues through a brief musical selection which heralds the ap- pearance of the ghost. The sound from the "phonograph rec- ords" is reproduced through five loud speakers located at various positions back-stage and controlled by a switching system which permits selective or simul- taneous operation. Thus, in the mob scene, by switching from one speaker to another in sequence the sound gives the illusion of a crowd surrounding and ap- proaching the citadel, and the weak, far- off murmurs and cries develop to a great climax and loud cheers when the gate is finally broken down. The prelude, overture, and entire mu- sical accompaniment to the show is re- produced over the system — there being no orchestra or other conventional music used in connection with the play. OPERADIO PORTABLE PUBLIC ADDRESS SYSTEM THE Operadio Mfg. Co. has added to their line of large public address equipment a portable public address sys- tem. The complete unit is carried in a single carrying case and complete with tubes, microphone and all accessories, the weight is only forty pounds. The input from the two-buttom micro- phone that is supplied, or from any 200- ohm phonograph pick-up, is raised by the three-stage amplifier to a volume level sufficient for addressing a group of people that may be assembled in a room 1,000 feet square. The amplifier operates from 110 volts, 60 cycle, A. C, and supplies power for all accessories including the dynamic speaker and two- buttom microphone. A control panel is provided with sep- arate volume controls for microphone and phonograph input, and a change- over switch for shifting the amplifier to either input. The cover provides stowage for a 50-foot rubber covered microphone lead and a 25-foot A. C. line cord. A jack is provided that al- lows from one to four additional A. C. dynamic or magnetic speakers to be op- erated without affecting the output of the main speaker. Operadio Portable Reproducer BRITISH 16 MM. SOUND FILM REPRODUCER The British Thomson-Houston Co. will turn out a reproducing set for 16 mm. film, which was demonstrated at the re- cent London Radio Show. A machine has been designed and is in use for re- ducing full-sized film to 16 mm., and it also reduces the sound track in the proc- ess. Printing is done from a 35 mm. negative straight on to the miniature posi- tives. The reproducer set weighs only 60 pounds, with dimensions of 24 in. by 18 in. by 8 in. The price, not yet fixed is expected to be under $1,500. NEW ERPI DIVISION HEADS The appointment of E. S. Gregg as General Manager of the Eastern Division, and of H. W. Dodge as General Manager of the Central Division, has been an- nounced by Electrical Research Products, effective immediately. Gregg recently returned from England, where he served as Managing Director of Western Electric Co., Ltd. Dodge has been Sales Manager of the Central Divisioii for several months, and before that was Merchandis- ing Manager in New York. mmna ***'***'^HTHH November 1931 INTERNATIONAL PROJECTIONIST 37 MECHANICAL HINTS Types of Machine Screws A description of the styles of machine screw heads and the method of measur- ing lengths as indicated by the distances between the arrows: J Round Head Screws have semi-elliptical shaped head. Flat Head Screws have a head with a flat top and a counter- sunk angle of 82°. Fillister Head Screws have a — r rounded surface for the top L of the head, the remainder being cylindrical. T Oval Countersunk Head or French Head Screws have a rounded surface for the top of the head and a countersunk angle of 82°. Screws Types of Oval Binding Head Screws have a head similar to Stand- T ard Round Head Screws with li the exception that the height 1 of the head is less. Flat Top Binding Head Screws have a head with a flat top and straight side. The height of the head is less and the diameter greater than that of Standard Fillister Head Screws. Standard Screw Thread Nomenclature The following terms have been adopted 3 American standard screw thread NUT SCREW nomeclature, and are recognized as such. Major Diameter. The largest diameter of a screw thread. The term "major diameter" replaces the term "outside di- ameter" as applied to the thread of a nut. Minor Diameter. The smallest diam- eter of a screw thread. The term "minor diameter" replaces the terms "core diam- eter" and "root diameter" as applied to the thread of a screw and also the term "inside diameter" as applied to the thread of a nut. Pitch Diameter. On a straight screw thread the diameter of an imaginary cylinder the surface of which would pass through the threads at such points as to make equal the width of the spaces cut by the surface of the cylinder. Pitch. The distance from a point on a screw thread to a corresponding point on the next thread measured parallel to the axis. Practical Hints on Assorted Jobs Varying Speed Motor. A motor in which the speed varies with the load, ordinarily decreasing as the load in- creases— for example, a series motor, compound motor, or series shunt motor — is called a varying speed motor. An in- duction motor with a high resistance ro- tor is also a varrying speed motor. Variable Speed Motor. A variable speed motor is one which can be operated at various speeds, and is usually under control at all times. Railway motors, crane motors and hoist motors are often of this type. Wound rotor induction mo- tors are variable speed motors, and, with proper control equipment, any direct cur- rent motor may be a variable speed ma- chine. Reaming Holes. A rat tail file makes a good reamer in an emergency. Put the file into a bit brace and operate the brace backwards. Soldering Ladle. A three-eighths-inch gas cap with a handle on it makes a valu- able solder ladle for soldering in close places. Wood Screws. In driving wood screws into hard wood a lubricant makes the job easier. A little machine oil, axle grease, or yellow soap on the thread of the screw saves the strength and patience of the mechanic. Linemen will have the twist- ing off of lag screw heads by using one of these lubricants. Oil Rings. A substitute for a metal oil ring for bearings can be made by using a piece of stout window cord neatly spliced to the proper size. The cord will soak oil and distribute it to the bearing top efficiently. GoldE S-Alarm A new and highly efficient projec- tion unit of vital importance to a good show 2 Start Motor 1— Get Ready GoldE S-Alarm Says: "I. Get Ready! 2. Start Motor 3. Change-Over!^' YOU can't help but give a smooth, unbroken show with this marvelous timing device. It gives three distinct signals. You can't miss them. You can't mis- take them. Good shows help the box office. Plenty of warning re- lieves you of worry. You don't have to watch the screen at all — a wink or sneeze can't make you miss a cue. Your machine is at full speed — and when you want it there. Not a chance for slow pick- up to spoil the show. Installed in five min- utes. Adjusted in five more. Never fails ! Nothing to get out of order. Made of steel, bronze, and duralu- min finished in black crackle lac- quer. Outlasts the projector. Pays for itself in convenience in one performance. Pays for itself at the box office in a month. Write for illustrated folder with full de- scription and moderate price. Another superior GoldE projection achievement GoldE Mfff. Co. g- 2013 Le Moyne St., Chicago, HI. 38 INTERNATIONAL PROJECTIONIST November 1931 Projectionists everywhere have acclaimed the su- perior qualities of INTERNATIONAL PROJEC- TIONIST as a craft publication. The unpre- cedented support accorded INTERNATIONAL PROJECTIONIST before publication was proven by the first issue to have been warranted. Sub- scription progress in the few weeks which have elapsed since publication of the first issue is out- lined below, and the details are significant in point- ing the way for the progressive projectionist. INTERNATIONAL PROJECTIONIST is an indis- pensable necessity in and out of the projection room. Your brother craftsman who is a sub- scriber will tell you that you cannot be without it. INTERNATIONAL Edited by LESS than a month after publication of the first issue INTERNATIONAL PRO- JECTIONIST is able to report a paid sub- scription list of more than 1,200 represented by projectionists in every state, but two, of the Union. Individuals, entire local unions, and educational societies recognize in IN- TERNATIONAL PROJECTIONIST the true craft paper. Claims of large circulation are easily enough made but less easily proven. Facts are what count. Here they are: Organization Subscriptions A.P.S. Chapter 18, Cleveland 183 Boston Local Union 182 191 Philadelphia Local Union 307 78 A.P.S. Chapter 7, Los Angeles 140 PROJECTIONIST James J. Finn Chicago Local Union 110 48 Westchester (N. Y.), L. U. 650 65 A.P.S. Chapter 16, San Francisco. . 71 Salt Lake City L. U. 250 34 New Orleans L. U. 293 26 Hamilton (Can.), L. U. 303 15 Publix Theatres, Home Office and N. Y. Area Projectionists 52 Kinema Guild (England) 17 Port Arthur (Tex.), L. U. 391 9 Total 929 This list represents ONLY the large bulk orders. I. P. has no agents and ali subscriptions are volun- tary on the part of and made direct by the sub- scriber. Others may talk about their non-existent large circulation; we prove ours. Paid subscriptions are the only real proof of reader interest. INTER- NATIONAL PROJECTIONIST has this reader inter- est and, what is more important, reader loyalty. Use this blank to record your sub- scription and insure receipt of all copies- If you are already a subscriber, pass along this blank to your brother projec- tionist. 1 Year . .$2.00 2 Years . . $3.00 INTERNATIONAL PROJECTIONIST 1 West 47th St. New York, N. Y. Date. 193. Enclosed is $ for year(8) subscription to begin with issue. Name Address City . . . I I Local State . November 1931 NOTES ON THE S. M. P. E. PROGRESS REPORT INTEREST in the adoption of wide film, though dormant for the past six months, is expected to be aroused again with the return of normal economic con- ditions. The high speed panchromative emulsions introduced earlier in the year have been given exhaustive trial under the severe working conditions prevailing in the studios, both in this country and abroad. General satisfaction has been expressed by the trade on their charac- teristics. Huse has described a pan- chromatic film which has the emulsion coated on a support having a neutral gray density of 0.2 which is claimed to minimize trouble from halation. Studio and Location. During the last six months, motion picture studios con- tinued to make their sound recording equipment more portable and to bring the talking picture gradually to the same technical perfection as the old silent picture. Studio Illumination. Very few new new pieces of illumination equipment were introduced in American studios. An addition to the cast silicon-aluminum equipment announced in the previous re- port is a new spotlight employing a 2,000- watt, 115-volt monoplane filament lamp. Sound Recording. Maxfield has shown tht an empirical relationship exists be- tween the placement of camera and microphone, and the acoustic properties of the set. Some eight or ten pictures INTERNATIONAL PROJECTIONIST 39 have been made using the technic, and the results were so well-liked that a more general application of the principles is being made. With a new intensity meter, it is pos- sible to measure sound and noise intensi- ties in sound stages and theatres. Levels from 15 to 100 decibels above the hear- ing threshold may be measured. The instrument is characterized by its com- pactness and lightness of weight. Satisfactory recording of frequencies up to 10,000 per second is claimed for the Fidelytone system of sound record- ing developed in England. An image of the cathode consisting of a long metal strip in an exhausted glass tube is formed on the moving film, the light glow extend- ing along the length of the cathode from the metal anode opposite its center point. The length of the glow varies in ac- cordance with the modulated input of the tube. According to a report from Hollywood, a new dynamic microphone has been in- troduced which has an essentially flat response from 50 to 10,000 c.p.s. The Metro-Goldwyn-Mayer studio have ac- complished an innovation by placing the microphone and associated amplifier in a spherical metal housing. Poor Processing Laboratory Practice. Laboratory proc- essing of negatives and master prints is quite satisfactory but evidence exists that much of this quality is lost in the prep- aration of release prints, on which the public judges the value of the entertain- ment of a picture. Recommedations are being drawn up to correct this serious production defect. Standard Kine Laboratories in Eng- land have installed apparatus for work- ing the Hepworth "stretched" negative process. Films taken at 16 pictures per second can be "lengthened" and subse- quently projected at higher speeds. It is claimed that "slow motion" films can be made by this method from normal nega- tives. Projection Equipment and Practice. Unperforated Czaphane film was pro- jecte on a Cinelux projector at a meeting of the French Societe de Photographic held this summer. Although the facili- ties did not permit reproduction of the recorded sound, it was reported that the demonstration otherwise was successful. Framing of the unperforated film was ac- complished by projecting light through images of perforations (printed along one side), onto a selenium cell connected to a one tube amplifier. Splicing is ac- complished by treating the surface with a normal zinc chloride solution at a tem- perature of 140° F. Sound Picture Projection. While there has been some improvement in the qual- ity of reproduced sound in the better type of theatre, during the past year there has been no radical improvement in the devices or in the method of repro- duction. Very slight improvement, if any, has been noted in the quality of Hoffmann - Soons Every known quality necessary in producing perfect projection is embodied in perfection rheostats. PERF^JiDN ^ SOLDERLESS ADJUSTABLE LUGS Heavily Constrncted Will take wire sizes from No. 4 to No. 4/0 Recognized as the highest standard everywhere [ Sold by all branches of the National Theatre Supply Co., Sam Kaplan, New York; Continen- tal Theatre Accessories, and by your dealer. ] The Only Union-Made Rheostat We Build Rheo. stats for Special Requirements. Communicate With Us Direct. There Is No Ob- ligation. R HOFFMANN - SOONS ELECTRICAL & ENGINEERING CORPORATION 387 FIRST AVE., NEW YORK HE OS TATS 40 INTERNATIONAL PROJECTIONIST November 1931 What does Television mean to You? H .ERE is a new book that gives all the facts about this new and amazing offspring of radio. Avoiding technical terms it follows the development of television right up to date, explains principles, methods and apparatus, and weighs for you the problems, possibilities and probabilities of television as a conunercial tool and a form of entertainment. Just Published TELEVISION by EDGAR H. FELIX Radio Consultant 276 pages, 5^x8, illustrated, $2.50 HAS television arrived at last? Can present broadcasting and receiving equipment be adapted to television? Will television of the future come by air or wire? This book from beginning to end was written expressly to supply reliable answers to these and hundreds of other questions yon may have asked regarding television. With many explanatory illustrations and diagrams it gives a thorough background of technical facts — then makes plain their importance from the standpoint of the experimenter, the commercial operator, the broadcaster, the "listener-in." Order from INTERNATIONAL PROJECTIONIST 1 West 47th Street New York, N. Y, Cavers television topics such as: —has Television really arrive J ? •^lie BOW and WHY of Television. — ansolved problems of Television, •—possibilities of 100-line system, —latest synchronizing methods. ^— the human eye in Television, ""-will fntnre programs come by air or wire? «»new developments affecting receiver design, -^^utnre progress of Television. 24 experts explain sound-recording and projection HERE is a book needed by every man connected with the practical side of the talking picture indtistry, in theatre or studio. Written by the men who taught the screen to talk it covers every phase, both technical and practical, of sound recording and reproduction. Recording Sound for Motion Pictures Published for the Academy of Motion Picture Arts and Sciences Edited by Lester Cowan 404 pages, 6x9, 229 illiistrations, $5.00 Answers many questions on: — practical technique of recording — booms, blimps and microphones — recording systems — film laboratories — assembling the talking picture — reproducing systems — practice and problems of sound projection TWENTY-four sections, each written by a recognized authority and specialist in his field, present an authoritative description and ex- planation of the fundamental principles involved in recording and repro- ducing sound for motion pictures and their practical application in the studio, on location and in the theatre. Everything essential or important is covered, from the fundamental nature of sound, down to the practical aspects of volume control, theatre acoustics, and other everyday problems of sound projection. Order frona INTERNATIONAL 1 West 47th St. PROJECTIONIST New York, N. Y November 1931 INTERNATIONAL PROJECTIONIST 41 reproduced sound in the smaller the- atres. A lamp for slitless sound reproduction has been devised by Dunoyer. Essen- tially the lamp consists of a cylindrical glass bulb having a flat piece of optical glass sealed in one end exactly parallel with a tungsten filament 25 mm. long and 0.1 mm. diameter. The filament is made in such a way as to be perfectly rec- tilinear at its normal temperature of 2290°K. The image of the filament falls on a triplet anastigmat lens which at a magnification of 8 gives a scanning zone of 3 mm. length by 0.0125 mm. width. Non-Intermittent Projection. A non- intermittent projector for very thin (cel- lophane) film was demonstrated suc- cessfully in Madrid, Spain. The film has a row of perforation along one side and the sound track is printed along the other border. Since the film moves con- tinuously, the sound record does not have to be displaced from the picture but runs alongside each picture. Screens. A new sound screen recently demonstrated in London consists of a special fabric upon which small semi- parabolic lenses %-inch in diameter are mounted with a special light reflecting cement. The spaces between the lenses are cut away. A screen 22 ft. by 17 ft. carries about 460,000 lenses. In a new type of reverberation meter supplied by Electrical Research Prod- ucts, Inc., sound energy is converted to electrical energy and a series of points are recorded on a waxed paper drum which give graphically the exact history of the sound decay. Television Systems. Short has pub- lished details on a television direct pick- up camera, in which the image of the person being televised is focused directly upon spiral number one of the scanning disc. The camera is mounted on a rub- ber-tired truck which runs under its own power. Detailed movement of baseball games, tennis matches, and airplanes in flight have been followed easily with the apparatus, and it is possible to move quickly from a "close-up" to a "long- shot." At the end of each scanning cycle in the Barthelemy system, the beam is in- terrupted a very short time. These lapses produce a 480-cycle frequency, which, filtered by an ingenious amplify- ing circuit, is used to operate a synchron- ous motor which drives the receiving scanning disc. A 3-watt lamp is used for a picture area of 600 sq. cm., as opposed to a 250-watt lamp for a 6 sq. cm. area in certain other systems. Color Cinematography. A new addi- tive screen process of three-color cine- matography was demonstrated success- fully before the Royal Photographic So- ciety in May, 1931. The manufacture of the film has been described by Periera, who states that 1,000-foot lengths of aceto-cellulose nearly 2 feet wide, are ruled with a three-color screen so that about a half milion squares cover each 35 mm. frame. A coating of collodion stained green is put on the base and a greasy ink resist applied to the surface by means of an engraved steel roller. A International Photographer Is a finely printed and beautifully illus- trated monthly magazine owned by the West Coast Cameramen's Union In all matters concerning the profes- sional motion picture photographers of the country it is the official organ It is designed to appeal to amateur followers of 16mm. cameras as well as to the most advanced technicians The columns of the magazine recog- nize the close relationship between the photographer and sound recorder If your news or kodak dealer does not carry the magazine on its coun- ters write for a sample copy to INTERNATIONAL PHOTOGRAPHER GEORGE BLAISDELL, Editor 1605 North Cahuenga Avenue, Hollywood, Calif. 25 cents a copy $3 the year bleaching bath then destroys the green dye where it is not protected. A red line screen, and finally a blue screen are next coated in an analogous way, as the first screen. A special panchromatic emul- sion of large sized grains is used as the last coating, so that on reversal of the neg- ative, a fine-grained positive is said to be obtained. A projection method of making duplicates is said .to have been perfected. New Device to Solve Fresh Print Problems To eliminate blurring of new film by oil that projectionists put on new prints which have a tendency to pull sprocket holes on first and second showings, N. M. LaPorte, of the research department of Paramount-Publix, is cooperating with the organization responsible for the proc- essing work for that company. "Within a few weeks, according to LaPorte, a mech- anism which is expected to go far in solv- ing this problem will be added to the processing unit. "A careful check on a questionnaire form sent out to the field indicates very clearly that damage to prints is caused on the first or second showing," said LaPorte. "The answers state that great difficulty is experienced in getting new prints to run freely through the projectors unless the projectionist squirts oil on the film. 48 INTERNATIONAL PROJECTIONIST November 1931 t^or i^MMMi t CHRISTMAS GREETINGS 1931 25""ANNUAL SEAL wwvv Ti^renty-five Years —the money from the sale of Christ- mas Seals has promoted: —the establishment of sanatoriums for treating tuberculosis — the finding of tuberculosis in time to effea a cure — health inspeaion of school children — the teaching of habits that help to insure good health — the bringing of rest, good food, sun- shine, fresh air, medical attention to sick children (S'Celp Cyigki {tuberculosis Buy Christmas Seals THE NATIONAL, STATE AND LOCAL TUBERCULOSIS ASSOCIATIONS OF THE UNITED STATES This not only blurs the picture but later, when the oil dries, gives the film an ap- pearance of buckling. However, it seems that after two or three showings the difS- culty disappears and the print runs through the projector without pulling sprocket holes or causing any other dam- age. This pulling of sprocket holes ap- pears to be one of the most serious re- production problems today. "For the benefit of those who might be interested in how we expect to elim- inate this grave print trouble, we can state that we are cooperating with the company which does our processing work in developing an apparatus to be added to each processing unit. This apparatus will burnish that part of the print that comes in contact with the projector. "After a print runs over the apparatus to be provided we shall have accom- plished that which is tantamount to two or three exhibitions of film in the the- atre, the difference being, however, that this operation of ours will have been done by an expert who knows his busi- ness and understands thoroughly the re- quirements of the theatre with regard to efficient processing. "Heretofore projectionists have been powerless to help the situation because they did not know that sprocket holes were being pulled until the film was re- moved from the projector." Some Common Causes of Reproducer Noise Sprocket Noise — Caused when the film pulls over to the left in the projector, al- lowing the exciter lamp of the light-ray reproducing system to play through the sprocket holes of the film as well as the sound track. The noise is a rather high- pitched buzz, somewhat like a busy door- bell. Flutter — This is a pulsation in the re- corded tones. It sounds as if the speaker is gagging a bit over a mouthful of mush. It is caused by too long or too short loops in the projector, or loose pads on the track guiding the film. These things cause both picture and sound track to move in-and-out of focus. Frame Noise — The opposite of sprocket trouble. Caused when the film is pulled in the projector too far to the right, run- ning off the sound track onto the picture itself, playing, so to speak, the picture and the dark spaces between the frames. Sounds like a motorboat at high speed. Motorboating — Same as Frame Noise. Overspeed — When the speed is sud- denly increased beyond the normal of 90 ft. per min. (33 1-3 r.p.m. for discs), the high frequency sounds are empha- sized at the expense of the lower ranges. In other words a basso would sound like a soprano under excessive overspeeding. Underspeed — ^When the projector is suddenly slowed down the reverse of the above occurs. The lower frequencies are emphasized, and a soprano would sound like a basso. Dirt Noise — Film should always be carefully cleaned after each running, but sometimes this is not done. When this happens, specks of dirt form on the sound track. These specks cause varia- tions of sound which are manifested in many ways — squeaks, whistles, fire- cracker noises, etc. Loose Exciter Lamp — ^When the excit- ing lamp of the light-ray sound reproduc- ing system becomes loose there is a dis- tortion of sound. Gear Noise — Noise recurring at regu- lar intervals, dum-de-dum, etc., can usu- ally be traced to loosened gears in the projector. Blooping — This is a sudden "plop," usually caused by a bad splice between sections of the film. This can always be avoided by correct splicing, and properly blocking out the spliced patch in the sound track. Insulation Noise — Some theatres have not yet installed the heavier tripods and insulation pads required for sound re- production. The amplifying tubes and the photo-electric cell are very sensitive to jar. Sudden "whack" noises from the screen are generally traceable to trouble caused by vibrations when the projec- tionist walks across a room in which the insulation has been badly done. There are other noises which can be caused by accidents and by faulty han- dling of the equipment, but the foregoing are the major extraneous sounds which annoy theatregoers. Mm t^Kummtmimmmmtrtmsa THE BOOK OF THE MONTH THE BOOK OF THE YEAR THE BOOK of the MOTION PICTURE INDUSTRY ^.>^" , ^NUAL ^AHERON J^ider ^rm. SOUND PICTURES AND TROUBLE SHOOTERS MANUAL By JAMES R. CAMERON and JOHN F. RIDER Introduction by WILLIAM F. CANAVAN (Inter. Pres. I.A.T.S.E. & M.P.M.O.) LATEST MOST COMPREHENSIVE AUTHENTIC BOOK ON THE SUBJECT PUBLISHED USED BY THE MOTION PICTURE INDUSTRY THROUGHOUT THE WORLD AS THE STANDARD AUTHORITY USE THE COUPON A COMPLETE GUIDE for TROUBLE SHOOTING U. S. DEPT. OF COMMERCE THE LEAGUE OF NATIONS (MOTION PICTURE SECTION) (CINEMATOGRAPH INSTITUTE) T-L L 1 //^ > \ u ij I :_ lU- "Mr. Cameron is one of the very limited 1 hese books (Cameron s) should be in the l r . i • i • . ■ ... number or technical writers on cinematography possession or every projectionist, theater man- really worth reading. " ager and everyone interested in receiving au- "His books are of particular interest be- thentic information regarding the application cause, although essentially technical and based «f ^^.,^A t„ ^,.t-:^^ .^;^»..»c r^n^o-nn'c knnlrc upon theoretic principles, they are nevertheless ot sound to motion pictures. Cameron s booKs -.i-.i <■ « .1. .1 . 1 • withm the grasp of any reader wishing to ac- are a worth while contribution to the motion q„;^g ^ knowledge of the sound-film in all its picture industry. aspects." ENDORSED BY THE TRADE PRESS THROUGHOUT THE WORLD 7^^ The making and showing of Sound Motion Pictures, Sound- MV CH jJl On-Film and Sound-On-Disc is covered thoroughly and in an '' J ^ _^^__ expert manner. The book is written so that the subject mat- M ■^~^~" ter is easily understood. Explains in detail the construction, m 1 AH 1 00 operation and care of sound recording and reproducing equip- ^ ^ ment. Every known trouble to sound equipment is listed in this book with full simple directions for its cure and explana- tion as to its cause. A Complete List of Our Motion Picture Books Sent on Request. I^_!^^IJ:!L^„^i^~L"il£.^£i'L^£A^^'^^^ book CAMERON PUBLISHING CO., WOODMONT, CONN., U. S. A. GENTLEMEN: HERE IS MY SEVEN-FIFTY. SEND ME A COPY OF SOUND PICTURES. NAME ADDRESS This is Type 59-A for use in RCA Equipmenf. There's a Visitron for every make of sound-on-film equipment. Banish your CELL WORRIES forever r If you want permanently perfect sound reproduction, with the trouble and ag- gravation of frequent adjustments for variation eliminated. USE VISITRON PHOTOELECTRIC CELLS. They cost no more than ordinary cells. Their bril- liant tone delivery at all frequencies, higher sensitivity, unsurpassed CON- STANCY throughout their extremely long life — are factors that should prompt you in your own interest, to INSIST ON I wo YEARS' steadfast service is not unusual for Visitron Photoelec- tric Cells. Guaranteed for One Year — but they rarely fail to exceed, even double, their warranted life. That's why they are known and re- ferred to as "the Long-Life Cell." Vrs IT RON PHOTOELECTRIC CELLS manufactured by \ LABORATORIES \HC 1737 Belmont Avenue, Chicago, 111., U.S.A. Order them BY NAME from NATIONAL THEATRE SUPPLY COMPANY f/nfernofiono/ JECTIONISl £c//fec/ hy James J. Finn RACQii SUPERIOR SpM^RS Throughout the world leading Sound equip- ment manufacturers have placed all types and makes of horns, speakers and units on exhaustive laboratory test. Engineers in nearly every case have chosen Racon Prod- ucts as being the acoustically perfect, most adaptable sound reproducers for Sound distribution. Whether or not you are satisfied with your present sound reproduction RACON assures you there is still room for improvement. Let us study your problem. Racon's Electro dynamic horn units are recognized as the finest that money can buy. Natural tone quality in any volume with Racon! GIANT ELECTRO Dynamic Horn Unit Continuous operating capac- ity: 7-10 watts. Peak load capacity: 25 watts. No 6320 Horn, illustrated above, has an air column chamber greater than 10 ft. Depth 37 inches. Bell 76x28 mches. Equipped with cast aluminum throat, patented self supporting frame, bronze coupling. A wide angle horn particularly adapted to distribute sound in theatres of extreme width— 50 feet or greater. Weight 60 pounds. Racon horns and units are covered by U. S. Patents Nos. 1,507,711, 1,501,032, 1,577,270, 73,217, 73,218, 1,722,448, 1,711,514, 1,781,489. Write for Complete Catalog Racon Electric Co., Inc. 18 Washington Place New York London, England Toronto, Canada Vol. I, No. 3 December, 1931 A magazine devoted to better visual and sound reproduction 25c. a CO $2.00 a y« For better quality picture and sound r e production Lightweight — yet sturdy, rigid and durable The Projection Reel Designed by a Projectionist for Projectionists 1\| O seams, no brazing and no welding to break open or come apart when rewinding or while in the projector. Made of a special aluminum alloy which results in a lightweight yet sturdy and rigid reel. No rough edges to cut the fingers or damage the film. The True Reel for Projection Sold by All Leading Dealers PRICES: 15 in. reel with 5 in. hub $3.00 each 11 in. reel with 5 in. hub $2.50 each Manufactured by W. & W. Specialty Co. 159 West 21st St. New York, N. Y. / JAN -S 1332 December 1931 INTERNATIONAL PROJECTIONIST PROJECTIONISl Edited by James J- Finn Volume I DECEMBER 1931 Number 3 Monthly Chat William F. Canavan Fundamentals of Testing Elec- tric Circuits A. C. SCHROEDER The Art of Continuous Cinema- tography William C. Plank Sputtering at the Arc Connecting D.C. Generators in Parallel R. H. McCuLLOUGH Why Anastigmatic Lenses? David Levinson and Alvin A. Hill Projectographs Wallace G. Crowley "Progress Through Understand- ?? mg A Purely Optical Slit for Sound- -on-Film R. C. Burt 11 12 14 15 16 17 Philosophic Background of Labor 18 Sumner H. Schlichter Disc Recording Improvement 19 Editorial Page 20 Squares and Rectangles 21 H. F. Dodge Canavan Resigns 22 Mathematics for the Projectionist 23 Siegfried S. Meyers A Serviceman's Diary Television Securities 25 25 American Labor Movement's 50th Anniversary 26 David Levinson From Foreign Fields 28 Notes From the Supply Field 29 A Model Form of Propaganda for Projectionist Unions 31 George A. Yager Miscellaneous Items News Notes Technical Hints Published Monthly by JAMES J. FINN PUBLISHING CORP. 1 WEST 47th STREET, NEW YORK, N. Y. Advertising Manager: James Beecroft Circulation Manager: Ruth Entracht West Coast Representative Hallett E. Cole, 846 South Broadway, Los Angeles, Calif. ('Phone: Tucker 6428) Yearly Subscription : United States and possessions, $2 (two years, $3) ; foreign countries, $2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Entire contents copyright, 1931, by James J. Finn Publishing Co^. International Projectionist is not responsible for personal opinions appearing in signed articles in its columns. Cover design by Morgan Bryan. MONTHLY CHAT INTERNATIONAL PROJECTIONIST has begun to spread itself. Reaching out to the West Coast it has gathered to its bosom "Loudspeaker," West Coast organ of the American Projection So- ciety. The arrangement naturally em- braces a transfer of all assets of "Loud- speaker"— subscriptions, advertising, and prestige — to LP. Paid subscriptions are, of course, of vital importance to any worthwhile publication; yet we like to think that of the aforementioned assets the most valuable is prestige. LP. is not insensible to the great re- sponsibility it has assumed through con- summation of this arrangement. Under the extremely able direction of Wallace G. Crowley, and by virtue of the support accorded it by Western A.P.S. men, "Loudspeaker" enjoyed an enviable repu- tation in the field and served its readers splendidly. We who work for LP. are conscious of the new responsibilities for giving service and of our now greatly in- creased audience. We shall try hard to discharge our obligation to former "Loudspeaker" readers by doing, if pos- sible, just as fine a piece of work as have Mr. Crowley and his associates. Had we acquired a string of sectional motion picture periodicals throughout the country (Heaven help us!), we should not have been more pleased than we are concerning the "Loudspeaker" ar- rangement; and we earnestly hope that our many new readers will bear similar friendly feelings for LP. This last should not be too much for which to hope, inasmuch as we shall continue to have the close cooperation of Mr. Crow- ley and his associates. OVERLY optimistic as we are, we have concluded that William F. Canavan's resignation as President of the International Alliance will serve one use- ful purpose: it will teach all units and the entire membership the meaning of self-reliance, the need for which was not so pronounced during Mr. Canavan's tenure of office. (PROJECTION has much to look for- ward to during the coming year, if only because it has not received its right- ful due during 1931. During the past year major emphasis was placed upon costs; production and reproduction were left to make their own way with whatever tools were available. It seems reasonable to assume that The equipment market will soon feel the impetus of purchases long deferred. *jM«tt!li^^a INTERNATIONAL PROJECTIONIST December 1931 AMPLION AMPLION OCTOPHASE GIANT DYNAMIC AIR COLUMN UNIT Weight 15 lbs. Height 5%^ in. Diameter 5^ in. Field Coil Resistance 5 ohms. Field Coil Supply 6 volts B.C. Field Current Consumption 1.2 amperes. Voice Coil impe<^ance 16 ohms. Maximum' Capacity 25 watts. Permanent Capacity 6 watts. Shipping Weight 21 lbs. Shipping Dimensions 12x12x12 in. This unit is also supplied with 1500 ohm field coil. Field Supply 110 volts D. C. Field Current Con- sumption 75 milliamperes. OCTOPHASE SPEAKERS OF ALL THE EQUIPMENT IN THE THEATRE THE LOUD SPEAKER IS ALL YOU HEAR Qive your amplifiers a chance It is those overtones from 5,000 to 8,000 cycles which give char- acter to speech. Can you afford to nullify your entire equipment by employing speakers which cannot reproduce these frequencies? for AUDIBILITY - INTELLIGIBILITY - DURABILITY EFFICIENCY and FREQUENCY RANGE Choose the Amplion OCTOPHASE It is so much finer, yet costs so little more CONSTRUCTION In this unit, the area over a scientifically domed diaphragm encased in a scientifically shaped air chamber, is divided into eight divisions. The cen- ters of gravity of each of these divisions are exactly equi-distant from the throat of the unit and since all operate under identical pressures, the sound impulses from each division reach the throat of the horn in perfectly timed synchronism with the arrival of sound impulses from all the other divisions. From these eight divisions, this reproducer derives its name OCTOPHASE. (Write for folder describing the OCTOPHASE UNIT and complete line of AMPLION EXPONEN- TIAL WEATHERPROOF HORNS.) AMPLION PRODUCTS CORPORATION 38 West 21st Street New York, N. Y. AMPLION NINE-FOOT THEATRE HORN JW-9 The JW-9 Horn is especially designed for theatre and indoor use. No horn of such great clarity and wide frequency range has ever been concentrated into so small a space. It covers the full speech range perfectly pre- venting over resonance and muffling on base notes. As a reproducer of music, it possesses a brilliancy impossible of attainment in horns made of soft materials. Its nine foot air column and wide bell, assure excellent performance on the low notes. List Price $95.00 Air Column 108" Bell 34" X 26" Bell Area 720 sq. inches Weight 33 lbs. Shipping Wgt. 70 lbs. Shipping Dimensions 38"x33%"x39" Angle of Spread measured at lip of bell 36° Height 42" Width 34" Depth 37" hm William F. Canavan WILLIAM F. CANA VAN'S resignation as President of the Inter- national Alliance was preceded by one of the most vicious campaigns of personal abuse that this writer has ever seen directed at a man in Canavan's high position and with his record of unparalleled service to an organization and its membership. And these vicious tongues have not yet been stilled. Canavan's resignation followed closely the adverse vote of the Local Unions of the Alliance on the question of a general wage re- duction. But the outcome of this vote was no more the reason for Canavan's action than were any number of silly reasons advanced by some of the "bright boys" within the craft and by some of the self- perpetuating local "czars" who saw in the wage reduction proposal, and in Canavan's subsequent resignation, an opportunity for divert- ing attention from their own delinquencies. Imagine the spectacle of a man like Canavan, who has devoted thirty years of his life to the Alliance, being subjected to the rawest, rankest type of abuse by those who are not worthy of even being seen in his company! Intellectually, Canavan towers head and shoulders over those who now wish to cast him into disrepute. One may honestly question Canavan's judgement, but one may not, cannot question his honesty, his unswerving sense of loyalty and years of zealous efforts in the cause of the Alliance. And before anyone taxes Canavan with an error in judgement in sponsoring the wage reduction plan, one should reflect that the plan was okayed by every Executive, every Executive Board member, every representative and many Local Union leaders prior to its being broadcast. This piece is not written in defence of Canavan. He is too im- portant a personage to require any defence. One of the two outstand- ing executives in the American labor movement, Canavan has com- piled a record that speaks for itself and which would be well-nigh impossible of attainment by anyone of his critics. "Bill" Canavan resigned his office not because of the outcome of the vote on the general wage reduction; not because he was through fig'hting and sweating for the laboring man; not because he had "failed to click" on a "deal", and not because he had "something soft to step into". "Bill" Canavan resigned because he choked on the indigestible mass of rot that he was asked to swallow by a group of dull-witted persons the collective I.Q. of whom would probably be found to be — 3, if that high. "Bill" Canavan had a taste of the rewards he might expect from another 20 years of sweating. "Bill" Canavan didn't "run out" — he just walked out. The Alliance could go on paying Canavan his salary for another ten years, without any work being done by him, and still not even begin to repay him for his labors in its behalf. For a man who has. successfully floated so many "deals", William F. Canavan will prob- ably surprise everyone by going to work for a living in the near future^ The motive behind this little essay is obvious. This little piece is admittedly an effort to pay public homage to one who this writer con- siders the very salt of the earth, to one who is deserving of nothing but the highest respect from his fellow craftsmen, and to one who has performed a difl&cult task in magnificent fashion. But more than any- thing else, these few words constitute a feeble effort to pay tribute to a man — a man's man, William F. Canavan. James J. Finn INTERNATIONAL PROJECTIONIST December 1931 TWO NOTEWORTHY ACHIEVEMENTS IN PROJECTION EQUIPMENT Complete rear shut- ter attachments show- ing framing device, shutter adjusting de- vice, framing light, hinged eye shield, cooling plate, fire shutter lever and gate opening device. B. &S. Rear Shutter reduces aperture heat by 70%, minimizes effect of warped and buckled film, and keeps film free from dust and dirt. Exclusive blade feature of this shutter keeps hot air from film and insures constant supply of cool air around the aperture. The results of a test by the Massachusetts Department of Public Safety in a Boston theatre on Janu- ary 19, 1930, are as follows: Without B. & S. Rear Shutter Aperture Heat: 1250° F. With B. & S. Rear Shutter Aperture Heat: 340° to 350° F. Installation can be made in one hour on any single- or double-bearing projector mechan- ism, without any cutting or drilling. Periodic oiling is the only maintenance requirement. Rear shutter equipment includes cooling plate, framing device, shutter timing adjust- ment, and a framing light. A hinged eye shield permits easy accessibility to the me- chanism. B. & S. Change-over consists of two shutter blades contained in a housing de- signed for attachment to the cone of the lamphouse and operates on either A.G. or D.G., at 110 to 125 volts. Novel design eliminates any possibility of double exposure on the screen, and makes the change invisible to the audience. B. & S. Change-overs operate efficiently on either A.G. or D.G., but coils for the proper current will be supplied on specification. Goils of the B. & S. Ghange-over will stand up under heavy overloads and will not burn out. The constant arcing in an ordinary change-over switch soon causes the metal contacts to burn and corrode. All B. & S. switch contacts are made of carbon that cannot corrode. B. & S. unique design also prevents the flash from touching any part of the switch. This switch cannot stick or bind and is positive in operation. B. & S. Ghange- overs have been used for many years in Publix, R-K-O, and other major theatre circuits. BASSON & STERN For fifteen years manufacturers of high grade motion picture equipment 749 EAST 32nd STREET, BROOKLYN, N. Y. INTERNATIONAL PROJECTIONIST VOLUME I NUMBER 3 DECEMBER 1931 FUNDAMENTALS OF TESTING ELECTRIC CIRCUITS A. C. Schroeder MEMBER, I. A. LOCAL UNION 150, LOS ANGELES, CALIF. TESTING is done to find out what conditions do or do not exist in an electric circuit. It is done with electrical instruments rather than "look- ing" for the trouble, because there are difficulties which cannot be found by looking — they occur somewhere within the apparatus or in some remote corner into which we cannot get to see what has happened. In other instances testing is resorted to because it usually locates the seat of the trouble quickly, whereas if we were compelled to look through all of the parts that are in any one circuit it would take considerable time, and when we finished we might find that the trouble is not in this circuit and the hunt would continue in another direction. Do not get the idea that visual exam- ination is of no value. A short inspection combined with the process of pulling and prying on leads, and so forth, will some- times reveal the trouble in short order. In some instances visual inspection is re- quired after the electrical tests have been made ; at other times the two methods are used together. Placing the hand on a suspected wire or apparatus often gives an indication of trouble by the amount of heat that is present. This must be done carefully, otherwise a skin burn might result. In order to know what kind of meter to use, what meter would be ruined if used on a certain test, or if the meter would ruin the part being tested, and also to interpret the results of the test, an understanding of ohms-law is essen- tial. This need not frighten anyone; it is simple and requires only a rudimentary knowledge of mathematics. Ohms-law is simply a statement of the relation exist- ing in a circuit between the voltage ap- plied, the current flowing, and the re- sistance in that circuit. If any two of these values are known, the third one can be found either by multiplication or by division. When the current and the resistance are known, the voltage is found by multiplying the two known val- ues. When the voltage and one of the others is known, the voltage is divided by the other known quantity. This relation- ship exists in all circuits no matter how large or how small the apparatus or the wiring may be. The current is the result of the voltage and the resistance. It cannot be changed unless the voltage, the resistance, or both the voltage and the resistance, are changed. A change of voltage or a change in the resistance always causes a change in the current. If the voltage is increased and the resistance is increased proportionately, the current remains the same. If both are decreased proportion- ately, the current again remains as it was. Let us consider a few examples in order to make this clear. In Figure 1 we have a battery, B, and a resistance, R, which are connected so as to form a closed circuit. For the first example we will assume that this is a small test cir- cuit on the bench and that the connect- ing wires have no resistance. This as- sumption is never true, but the resistance of the wires in this case is very low and can be neglected. The voltage of B is 10, the resistance of R is 5 ohms. If B is a storage battery in good condition, its resistance will be very small and can also be neglected. The current in such a circuit will be found by dividing 10 by .5, which shows- that 2 amps, are flowing. A voltmeter across the battery will read 10. If the meter be put across R, it will also read 10. An ammeter inserted in the line at X will read 2 amps. Placing the same resistance, which may be an electric light, at a point 100 feet away, we must use two connecting wires, each of which is 100 feet in length. The resistance of these two wires is 5 ohms and cannot be ignored, since it will affect the result a great deal. The total resistance in the circuit is now 10 ohms (5 ohms in R, and 5 ohms in the wires). Ten divided by 10 gives us 1. Only 1 ampere is flowing in the circuit now. One ampere is not sufficient to light the lamp properly. Let us see what condi- tions have acted to cause this. Placing the voltmeter across the bat- tery we see that there still are 10 volts Figure 1 ^M fi X [7] 8 INTERNATIONAL PROJECTIONIST December 1931 at this point. We place the meter across the resistance and get only 5 volts. Ap- parently some voltage has been lost be- tween the battery and the resistance. Taking the voltage across the resistance, which is 5, and dividing by 5, the num- ber of ohms, again gives us 1 amp. as the current. To illustrate a different angle, we draw the circuit shown in Figure 2. R has been moved next to the battery, where it is connected by a wire having practically no resistance. The loop of wire extend- ing from R to X and back to the battery is 200 feet long and has 5 ohms resist- ance, just as the two wires had in Fig- ure 1 after R had been moved 100 feet from the battery. An ammeter will show a flow of 1 amp. A voltmeter across the iattery shows 10 volts. The meter is 710W placed across R, and the reading is -5 volts as before. One lead from the meter is then touched to point 2 at the lower end of the hattery, and with the other lead placed ■on 3 at the far end of the resistance, a reading of 5 volts is obtained. Inspection ■of the drawing will show that we are measuring the voltage across the wire that connects the battery and the resist- ance, that is, around the 200-foot loop. It takes 5 volts of the battery potential to. force the current through the loop of wire. We know that the resistance of the wire is 5 ohms. Dividing thfe voltage drop in the wire by the resistance of the wire gives us 1, which is the number of am- peres flowing. As the current remains constant so long as no change is made in the cir- cuit and the battery is not discharged, then our answer in amps, must be 1, re- gardless of how the calculation is made, and right here we must watch our step. Notice the italics in the previous para- graph. To apply ohms-law we must be very careful not to get the various parts ■of the circuit mixed up. Had we taken the voltage of the battery and divided it by the resistance of the long loop of wire, we should have had a wrong answer. Mistakes such as this are very easy to make when dealing with circuits that are more or less complicated, but this is no fault of ohms-law. The law always holds good, and when it seems as though it will not work in some cases, it is because we do not use it properly. The voltage of the battery (Fig. 2), is also the voltage across that part of the circuit starting at 1, through the resist- ance, R, out on the long stretch of wire to X, and back again to point 2 at the ^ 3 DISTRIBUTION of more than 450 baskets of food to poor families just before Christmas is the proud record of Local Union 160 of Cleveland. This job was handled in its entirety by the Local: the neediest poor families were canvassed and listed, the food was bought and the baskets packed and distributed by the Local membership. Also, the cost of every bit of the food as well as the job of canvassing, packing and distribution was borne by the Local. Every member of the Local partici- pated in the manual labor involved in this great task. Before work, after work, and often long into the night, men who had put in a full working day in projec- tion rooms cheerfully "went to it" and contributed their bit to the success of the plan. There may be better means than this for building community goodwill for a labor organization, but if there are, we have near heard of them. J. J. F. other end of the battery. In applying ohms-law, when we consider the voltage across the entire circuit we must also consider the resistance of exactly the same circuit. The result will then be correct. Before passing on from Figure 2, let us make a different application of ohms- law. It is desirable to know what the resistance of the wire is from R to the point X. It would probably be 2.5 ohms, but this is not positively known. The voltmeter terminals are applied at 3 and at X, and the voltage is found to be 2.5. 2.5 divided by 1 gives 2.5, the number of ohms in that part of the wire. To measure the voltage in this part of the wire it is necessary to have a wire on the meter about 100 feet long to reach X. In the present problem this makes no difference, but there are some cases where that length of wire would give an erroneous reading. We will discuss that phase of the problem in connection with other circuits later on. Assume that we have two vacuum tubes wired in parallel, the normal filament voltage being 4.5 and the current through each tube 1.6 amps., or a total of 3.2 amps, for both tubes. A rheostat is in series with the tubes so as to cut the voltage from 6 to that required by the filament. The source of current is a 12- volt storage battery. A difference of 6 volts exists between the battery voltage R UK ^5 Figure 2 Figure 3 and the voltage we need across the cir- cuit in the amplifier, so a resistance is used to consume the excess voltage. We desire to find out what value of resistance it will take to produce the 6-volt drop. The unknown quantity is the resistance in ohms; the two known values are the voltage to be dropped, which is 6, and the current that is to flow through the additional resistance, 3.2 amps. Dividing 6 by 3.2 gives 1.875, the number of ohms required. In practice, a resistance of 1.8 or 1.9 ohms would be used. The rheostat will take care of the difference caused by the fixed resistance being of a slightly differ- ent value. Figure 3 is a diagram of the circuit. Actually there would be a switcli and a number of wires connected to other circuits in the amplifier, but these do not affect the filament current and we need not take them into consideration. R is the fixed resistance, RH is the rheo- stat, and the two resistances, T, repre- sent the filaments of the vacuum tubes. While we have the circuit in Figure 3 under discussion, let us see what occurs if one of the tubes should burn out. As it stands now, we do not know the re- sistance of the filaments nor the resist- ance of that portion of the rheostat which is in use. We know that the current through the rheostat must be 3.2 amps., and we know the rheostat must cause a drop of 1.5 volts, from 6 to that required by the tubes, which is 4.5 volts. 1.5 di- vided by 3.2 gives a figure very close to .469 ohms, the resistance being used in the rheostat. The filament resistance of one tube is found in the same manner — 4.5 divided by 1.6, or 2.8 ohms. Possibly it isn't clear why we divide by 3.2 in one instance while in the other we divide by 1.6. The current through one tube will be 1.6 amps, when the voltage impressed on the filament is 4.5, conse- quently we must divide the voltage by 1.6. The rheostat is adjusted until the current through both tubes is 3.2 amps. This same current is also flowing through the rheostat, which causes a drop in the rheostat of 1.5 volts, so 1.5 is divided by 3.2 to find the number of ohms. Having found the resistance of all the apparatus in the circuit we add them all together: — 1.9 ohms in the fixed resist- ance, .47 ohms in the rheostat (.47 is close enough to the actual value, .469 ohms) ; and 2.8 ohms in the filament of the tube. The sum of all three resist- ances is 5.17 ohms. The resistance of the wires is negligible. Dividing the battery voltage, 12, by the total resistance in the circuit, 5.17, gives us a current of 2.S amps, through one tube. This much cur- rent through a tube designed to carry only 1.6 amps, will very rapidly ruin it. Next month our article will delve deeply into testing, and we will find ohms-law creeping into the picture again and again as we go along. THE ART OF CONTINUOUS CINEMATOGRAPHY William C. Plank //. The Mechanics of the Continuous Projector MECHANICALLY, the continuous cinematograph is a simple de- vice, there is nothing intricate about it whatsoever, and to project steady motion pictures upon this principle is easy. Steadiness becomes entirely a mat- ter of workmanship, for the principle lends itself to great steadiness. But def- inition, or quality in the image, is en- tirely a matter of the optical principle employed. So continuous cinematographs may be very appropriately likened to ob- jective lenses, in that it is a very simple and easy matter to obtain a mediocre image with them, but more difficult and involved to obtain an image having qual- ity. The cardinal requirement in the con- tinuous cinematograph is a rectilinear or straight-line displacement of all the con- jugate points. The definition and flatness of field will always be found to depend upon how perfectly this requirement is fulfilled. In the continuous cinemato- graph devised by the writer (see illus- tration), the compensating elements are rhomboidal-shaped' prisms which possess the rare and peculiar virtue of satisfying the above condition. In the continuous camera (see Fig. 1), they give a straight- line displacement to all the image points. These totally reflecting prisms are re- volved in such a manner that their faces are always maintained perpendicular to the optical axis. The axial ray, there- fore, always enters and emerges normal 1f-^^-^ ' A four-sided figure having its opposite sides equal, and its angles not right angles; lozenge- shaped. Continuous cinematograph to these faces. And in its passage through the two prisms it undergoes total reflection four times, in a manner somewhat similar to that in prism binocu- lars and other prism instruments. The conditions for definition are, therefore, similar. The axial ray is displaced, not de- flected, to compensate for the motion of the film. The advantage to be noted in this is that the compensating principle is independent of the objective lens. The moving film will appear stationary when viewed directly through the prisms, with- Figure 1 out the lens in place. Hence, objective lenses of any focal length may be used. Matching the Reflectors Next in importance to the optical prin- ciple involved, is the matching of the plurality of compensating elements that go into a continuous cinematography, for this also has a great deal to do with the definition and quality of the image. Here, the reflective systems present an obvious advantage, for it is not difficult to match plane reflectors or optical flats. Any number of them can be matched so that the images reflected by them will match very accurately in size and com- position. Needless to say, this is an im- portant requirement in superposing them upon the screen without loss of definition in any part of the projected image. In a reflective element this virtue is not con- fined to a central portion only but ex- tends to the very edge of the compen- sating element. Given a compensating principle that is sufficiently perfect to satisfy the re- quirements as to definition, and a plural- ity of accurately matched compensating elements, the only problem remaining is to mount the compensating elements and index them with precision. Here again, the rhomboidal prisms evince peculiar and unique advantages. If their faces be maintained perpendicular to the optical axis, they become insensible to every ad- justment or movement but one — the ad- justment with respect to the radius. This makes it easy to mount and index them. (See Fig. 4.) But a still greater advantage is that the precision or uniformity of the prisms cannot be affected readily in the mount- ing. The precision or uniformity of the optical intermittent movement depends upon the distance between the two paral- lel reflecting surfaces of the prisms, which may be ground and polished flat and parallel to within two wave-lengths. It is this precision that is not easily af- fected in the mounting of the prisms. Precision Registration Tilting a prism with respect to the op- tical axis (see Fig. 3), will move the pro- jected image laterally upon the screen; and adjusting it with respect to the radi- cal position will move the image up or down. It will be seen, therefore, that these two adjustments suffice to make the 10 INTERNATIONAL PROJECTIONIST December 1931 Cffoss-m/Rs FOC/9L .Point. TO SCREEN ^^ ^^^5S^^ Fig. 3. Sectional plan view, greatly exaggerated. Tilting the prism with respect to the optical axis moves the image laterally on the screen. Very little of this adjustment is required. Adjusting the prism with respect to the radial position around pivot screw moves the image up or down. These two adjustments suffice to make the prisms register with great precision prisms register with great precision when they are indexed. Each prism may be easily adjusted to make the image of cross-hairs register to within one-hun- dredth of an inch upon the screen, or even closer. In fact, this precision of the registration is only limited by the pre- cision of the dividing head used for in- dexing. And assuming uniform motions in the prism wheels and in the film, this will also determine the precision of the registration of the successive images upon the screen. The really important thing, however, is that when the prisms are once indexed and fixed in place, the precision of their registration becomes permanent and cannot vary because of wear; otherwise such precision would be quickly lost. A word should here be added about film shrinkage. In every continuous cine- matograph means for correcting or com- pensating its effects should be provided. In our rhomboidal-prism cinematograph this means is very simple and effective. A thin lens is interposed between the com- pensating prisms and the film; and by adjusting this lens the film can be mag- nified up to its proper size. The amount of magnification necessary is very little, for although film shrinkage is measur- able in a foot of film, in one or two frames it is almost inappreciable. By using a variable speed drive for the film, it can be shown that the frames move downward on the screen if the velocity of the film be too slow, and up- ward if it be too fast. Synchronism of the film photographs with the compen- sating elements is, therefore, necessary to maintain the picture in frame. The factors that enter into the registration of the continuous cinematograph are four. And it can be proved that if there be synchronism, a uniform motion in the film, and uniform motions in the com- pensating elements, the registration of the successive images will depend en- tirely upon the precision with which the compensating elements were adjusted or indexed. The projectionist will now see why precision in motion picture projection has been advanced to a new high. It is a precision of so high an order that the factor of wear must not be allowed to enter into it, else it were futile and a waste of effort. But registration is now upon a much higher plane. It concerns itself only with uniform motions and no longer deals with wear. Wherever wear occurs in the mechanism, it is of no par- ticular concern as long as it does not affect the uniformity of the motions. And, fortunately, the wear in a continu- ous cinematograph does not: for parts such as the spiral gears, which revolve the compensating wheels in opposite directions, may be worn thin without af- fecting the uniformity of the motions. The Gear Train These right- and left-hand spiral gears constitute the heart of the mechanism. In the simplest form of the device, the sprocket is mounted on the shaft which carries the right- and left-hand spiral pinions, and this reduces the mechanism to but three moving parts, all of which revolve at unusually low velocities. The wear on gear teeth depends largely upon the pressure exerted by them, or the amount of work they do; and it will be seen that the work in the continuous cinematograph is very light — turning over two freely revolving com- pensating wheels which, once set in mo- tion, require but a minimum of effort to keep them revolving. The outstanding feature of this construction is, therefore, its extraordinary capacity for maintain- ing the precision. Wear is thus elimin- ated as a factor in the mechanism of the continuous cinematograph. The foregoing considerations are suffi- cient to show that if a uniform motion be imparted to the film, the very summit and peak of precision in the registration of the successive images can be attained — and, what is of more importance, main- tained throughout a long period of time. In recording and reproducing sound, many of our technicians have become familiar with the advantages of a uni- form motion in the film, and have di- rected their efforts toward obtaining it. Impedance rollers and heavy fly-wheels are responsible for a technic that ap- proaches the theoretical limit of perfec- tion in imparting a uniform motion to the film. And the thing to be noted is, that it is accomplished without the slightest dependence upon the accuracy of the perforations. Wear and inaccu- racies are thus eliminated as factors in the perforations of the film. The perforations become of minor or secondary importance; and accuracy is no longer their predominant requirement. Their chief office is now to prevent the image from creeping out of frame. For this purpose only one row of perforations is necessary, and their size, shape, and number, may be varied greatly without affecting the results. It naturally follows that those tech- nicians who have learned how to impart a uniform motion to the film, and who appreciate what this means in precision, will be eager to see the registration of the successive images in the camera, in the printing machine, and finally upon the screen, likewise placed upon this much more accurate and scientific prin- ciple. And when they have reached thi& stage, we hold they have become uniform- motion-minded, a harmless distemper that is destined to become epidemic. A Representative Opinion But with every new art, there is a long struggle to overcome the effects of preju- dice or propaganda and obtain a foot- hold. And those of us who have en- deavored for years to create an interest in the fascinating art of continuous cine- matography know what this inertia amounts to; for the greater the mass of an industry, the greater becomes its in- ertia. Every new movement meets with inertia, however, and must overcome it. The following is an example of what has to be overcome in the average en- gineer, and it is given here because it represents very accurately the attitude of the motion picture industry itself with regard to the continuous cinematograph. About a year ago we happened to write to the secretary of a society of engineers upon the subject of continuous projec- tors, and he replied in part as follows: "Frankly I have no faith in a continu- ous projector, although this is merely my personal opinion, which is the result of having inspected quite a number of them .... Even if a continuous projector could be made perfect in all respects, what of it? What would it do or offer in the way of advantages to offset the high x--!-^ Fig. 4. The displacements have no effect upon the image December 1931 INTERNATIONAL PROJECTIONIST 11 cost which seems to be inherent in this type of machine?" It is the purpose of this article to tell what the continuous cinematograph can ■do and offer. Every projectionist is fam- iliar with the erratic behavior of thin- spindled, easily warped, high-speed, in- termittent mechanisms, when affected by heat, dryness, stickiness or grit. He has witnessed erratic projection with new mechanisms and, of course, he knows how soon precision can be lost because of wear. The fact is, with intermittent projection, steadiness is a variable quan- tity; and we have all witnessed instances of eye-straining unsteadiness in some of our best theatres. These instances of er- ratic projection may be traced to the •erratic behavior of the intermittent mech- anism, or to the condition of the perfora- tions on the film. With the intermittent principle the registration is absolutely dependent upon the accuracy of every perforation on the film. This is an inherent defect, for it is inseparable from the imperfect and un- scientific principle of the registration. It is one of the crudities of the intermit- tent method, for the film (a non-metallic material), is made one of the most im- portant and sensitive parts of the mech- anism. It is employed as a mechanical chain, connecting the frame at the aper- ture with the teeth of the sprocket. But liow crude its links appear, in contrast with the quality of the material and the finish of the other equally sensitive parts of the precision mechanism. Instead of teing made of the finest steel they are made of thin celluloid, highly subject to wear, to breakage, and to loss of shape. Among the other parts of the precision mechanism this crude chain is an incon- gruity. But this is not all. Instead of subject- ing it to a treatment more in keeping with its crudeness and the material of which it is made, a miracle in the way of performance is demanded of it — pre- cision of a high order at the extraordin- ary rate of twenty-four severe jerks a second. It is no wonder, therefore, that instances of consistent projection are rare, and perfect projection rarer. And although the crude chain seems to stand the strain, the projection can never be more accurate than its weakest link. So it is worthy of note that the con- tinuous cinematograph offers a real solu- tion to the problem of erratic projection, whether the cause be in the mechanism or in the film. Old and badly worn film can be projected with surprising steadi- ness and smoothness as the registration does not depend upon the condition of the perforations. Another crudity of the formative or adolescent period of cinematography is flicker. Whether perceptible or imper- ceptible, flicker is a crudity in motion picture projection for which there is no SPUTTERING AT THE ARC SPUTTERING at the arc may be caused by carbons not being properly set or trimmed, or too short an arc; more frequently, though, it is caused by a damp carbon. Carbons are porous and absorb moisture. They are baked at extremely high temperatures; and when they leave the factory they are thoroughly dry. In shipment, however, they may be exposed to damp weather, or at destination stored in a damp basement. Carbons should be kept in a dry place. A great many projectionists have formed the habit of laying a few carbons on top of a rheostat in order to expel any moisture that might have been absorbed after leaving the factory. Others put a trim in their lamp- houses before burning. Either practice is a good one and is to be recom- mended, as a damp carbon may chip at the crater in addition to causing a sputtering arc. Carbons are not perishable: they will be as good ten years from now as they are today. If they have absorbed water only, they can be dried out in the manner just referred to. However, if a chemical has been spilled on them, they may be rendered worthless, depending upon the nature of the chemical. relating to continuous cinematography lie. And this is possible only because the public does not know it. The "Belladonna Effect" On account of the "Belladonna effect" (the undue dilatation of the pupils when viewing intermittent projection), many instances of injurious practice occur throughout the country. The excessively brilliant light-periods or "peaks" strike in upon an unprotected retina through an aperture or pupil that is much too large for their intensity. This is the natural consequence of the inability of the iris to respond at the high frequencies em- ployed. It becomes more or less fixed or adjusted to an illumination on the retina that is an average of the different inten- sities of the intermittent light falling upon it. The aperture or pupil thus formed will be suitable for this average brightness, but for no other. Under these artificial conditions the iris fails to adapt the eye to the excessively brilliant light- periods. The idea that the human eye becomes adapted to intermittent illumination is a mistaken one. Insidious and unnatural conditions attend the artificial adap- tation. This can be made more apparent by an exaggerated example — viewing a bright light source through a revolving shutter. By increasing the area of the blade without restricting the opening, a high intensity arc could be viewed di- rectly; but it is obvious that this kind of adaptation would be false and unnatural. But if the excessively bright light-per- iods in intermittent projection are a crudity, the dark-periods constitute an- other. The alternations of the two ex- tremes give a screen luminousity curve of which no projectionist will boast. In fact, such a curve will serve to illustrate what a screen luminousity curve should not look like — and why. One of these reasons is that the alternations of brilliant light with darkness form an ideal condi- tion for inducing photo-electric effects within the retina. Nerve and retinal fa- tigue are the only possible results, for they can serve no useful purpose. A defect associated with eye-strain is the loss of definition in horizontal lines, which has become more prevalent since higher rates of projection have been in effect. This is sometimes due to motion or "creep" in the film during the so- called stationary period. A loss of defi- nition in the horizontal lines is so indica- tive of this condition, that the projec- tionist will appreciate the fact that the continuous cinematograph actually gives a true stationary period at the highest possible rate of projection. This im- proves the definition and lessens eye- strain. We hope that we have now pointed out to projectionists the new things made possible through the art of continuous cinematography. It is a new art, and accomplishes new and important effects by novel methods. But there is no doubt that it will become a great art. Its field or scope is broader than that of inter- mittent cinematography. The restrictions as to the size of frames or the rates of projection are removed, almost entirely. Its flexibility ranges from four frames a second to more than four hundred. This makes possible great advancements in reproducing sound as well as motion. In registration we have shown it to be more accurate, and in the substitution of the successive images, more subtle and scien- tific. In the future it has great possibilities; but the immediate reality and fact is that this new art brings comfort to the eyes, and adds life, roundness, and beauty to motion pictures. [Editor's Note: Mr. Plank ivill be glad to answer in these columns any question relating to continuous cinematography. Inquiries may be addressed to Mr. Plank in care of this publication. 1 1? JNTERJVATIONAL PEOJECTMNIST December 193J CONNECTING D. C. GENERATORS IN PARALLEL R. H. McCuUough DIRECTOR OF PROJECTION AND ELECTRICAL EQUIPMENT, FOX WEST COAST THEATRES THE theory and design, and also the electrical connections of direct-cur- rent generators, is one of the most interesting branches in connection with motion picture projection. Direct-cur- rent generators are classified according to the method of energizing their field magnets — such as series-, shunt-, and compound-wound. The compound-wound machine is most commonly used for mo- tion picture projection purposes. Shunt and series field coils form part of the compound-wound generator, which provides automatic electromotive force regulation. A generator is said to com- pound as the generator voltage increases with line load increases. A compound- wound generator is termed to be "flat compounded" when the voltage remains practically constant for all loads. Pro- viding the compounding is properly ad- justed, the series field will correctly regu- late the voltage for all changes in load within limits. To obtain the best results with gener- ators connected in parallel, they should be of the same design and construction and should possess as nearly as possible the same characteristics. While any number of generators may be operated in parallel, we will confine our explana- tions herein to the operation of two gen- erators. It is not practicable to run a compound generator and a shunt-wound generator in parallel because when excessive load is placed on the line the shunt gener- ator will drop in voltage, and unless the field rheostat is adjusted continually for the shunt generator, the compound gen- erator will take more than its share of the load. An equalizer connection be- tween the two compound generators is required when it is desired to connect them in parallel. Equalizer Connection The equalizer connection between the two generators operating in parallel con- nects where the armature and series-field leads join. This connects the two arma- tures and series-field coils of the two generators in multiple. This provision will divide the load between the gener- ators in proportion to their capacities. If the generators were operated with- out an equalizing bus, and if for some reason there was an increase in speed of one generator, it would take more than its share of the load. The increased cur- rent, which would flow through its series- field, would naturally strengthen the magnetism, which would raise the vol- tage and cause one of the generators to carry a still greater amount — until it car- ried the entire load. Therefore, an equal- izer bus always insures uniform distribu- tion among the series coils of two com- pound generators connected in parallel. If both generators are alike and pos- sess the same characteristics, the current in each would be one-half the total at all times, since at the same terminal voltage the same value of current would be de- livered by each. It is concluded that gen- erators having unlike characteristics will not operate satisfactorily in parallel; whereas those of like characteristics will. Accompanying this article is a sche- matic which presents the simplest out- line for connecting two compound motor generators in parallel. With this method of connecting two generators in parallel, either generator can be operated sepa- rately if it is desired to do so, thus pro- viding for flexibility in operation. Correct Procedure Assume that No. 1 generator is run- ning at the correct r. p. m. — the armature of generator No. 1 is generating its full voltage, which is indicated on the volt- meter— the following procedure is neces- sary to complete the circuit from the gen- erator to the d. c. board: The No. 1 single-pole relay switch, which is manually operated, is closed, which causes relay No. 1 to close, thus causing the d. c. contactor of No. 1 gen- erator to close. The coil of relay No. 1 is energized from the load side of the motor generator auto-starter, or across the line starter, whichever it may be. When the relay coil is energized, this permits the relay contacts to close, thus energizing the coil of the d. c. contactor. When the d. c. contactor is closed, the circuit is completed. The relay coil is connected to the load side of the motor generator starter for the protection of this circuit. All types of motor generator starters are provided with an overload relay, and any overload which may be placed on the motor generator set, would automatic- ally break the motor circuit and, provid- ing this circuit was broken through an overload, the energizing circuit of the re- lay, which causes the d. c. contactor to close, would automatically be broken until the motor generator was again started. The d. c. contactors for each of the generators connected in parallel are con- nected to the positive leg of each gen- erator. The voltmeter, ammeter, and field rheostat are connected ahead of each d. c. contactor. The voltage of each generator should be the same when op- erating in parallel, therefore it is always advisable to check the voltage before closing the circuit of either generator. If the voltage is high or low, correct same , by varying the field resistance accord- ingly. Cutting-In No. 2 If it is desired to use only No. 1 gen- erator for a certain period of time during the day or evening, and then later when generator No. 2 is required for the heav- ier load, generator No. 2 may be started as per starting instructions of No. 1 gen- erator. When generator No. 2 is up to full r. p. m. with full voltage, then throw- in the single-pole relay switch for No. 2 generator, which completes the paral- leling circuit. No. 1 and No. 2 generators are now operating in parallel. Motor generator No. 1 and No. 2 may be cut in and out of the paralleling circuit as de- sired. Either motor generator may be used as desired. If both generators are used at all times, there are a few points which should be considered. For the protec- tion of the circuit, always be sure that the relay switch is open before starting each generator. The generators may be started simultaneously, if it is desired to do so; however, it is not advisable to throw in both relay switches until the full voltage is attained for each gener- ator. Always leave the incoming gen- erator relay switch open until the gen- erator has attained full voltage, after which the relay switch may be closed for paralleling. Coupling Varying Capacities Great care is required for paralleling compound motor generator sets. For dis- connecting the motor generator sets from the paralleling circuit, the same steps are taken, only in exactly the reverse order, as explained for starting. Compound generators of different size or current capacity may also be [13] WHY ANASTIGMATIC LENSES? David Levinson and Alvin A. Hill THE widespread introduction of "corrected" or anastigmatic lenses in projection work, prompted by changing conditions in the motion pic- ture field and the constant desire to im- prove the quality of projection, is a mat- ter of comparatively recent record. Projection lenses generally in use before the advent of anastigmatic lenses have in principle been of the Petzval type used in portrait work, or of the short- focus type, "which amounts essentially to a telescope objective with an achro- matic condenser mounted a short dis- tance ahead of the film, which functions simultaneously as part of the illuminat- ing system and part of the projection objective. Both of these types are char- acterized by the very sharp central def- inition and a very limited portion of the field which can be called flat." An anastigmatic lens is one that has been fully corrected for spherical aber- ration, astigmatism, and chromatic aber- ration. Spherical Aberration Spherical aberration arises from the nature of the curve used in "uncor- rected" lenses. These lenses have spher- ical curves — that is, they are ground as part of a sphere. The consequence is that a section of a sphere, or an ordinary projection lens, not having curvature enough towards the center, has an infin- ite number of foci at different distances. There is a difference of the refractive power of different portions of the same lens, the marginal portions of the lens having an excess of refractive power as compared with the central portions which excess of refraction increases with the distance from the center. Astigmatism, a form of spherical aber- Connecting D. C. Generators in Parallel (Continued from preceding page) coupled, provided, of course, their vol- tages are equal and provided their re- sistances of the series field-coils are in- versely proportional to the current capa- cities of the two generators — that is, if one generator produces twice as much current as the other, its series-coil should have one-half resistance. It is further necessary that the two generators should agree in their action, so that a given in- crease in load will produce the same effect upon their voltages. If they are not in agreement, they may be adjusted by slightly increasing the resistance of the series coil of that generator which tends to take too large a share of the load. ration, is created when rays from an ob- ject passing obliquely through a lens converge through two focal planes in- stead of coming to a single point. The images thus formed do not focus with clean-cut lines on the screen. There also is a decided lack of contrast, and the projected image is more nearly a mono- tone in gray than a true black-and-white. "It is an unfortunate provision of na- ture," writes one scientist, "that a single lens applied to the task of forming an image gives us an image about as far from the quality we want as could well be and still have it recognizable as an image. The ideal image is the true pro- jection of the object spaces onto a plane, such a projection as might be constructed by drawing single lines from every point in the object space through a pinhole and continuing them until they intersect the desired plane of projection. "The images formed by a lens differs from this ideal in many respects. In the case of the pinhole, the image is equally sharp no matter at what distance from it lies the plane of projection, for it is assumed to be so small that only a single ray of light from any one object can pass through it. The lens, however, is of finite size and many rays from any one object are received by the lens. For perfect performance all these rays should be re- united by the lens in another point in the desired plane of projection (the focal plane of the lens). "It happens otherwise, however, as is illustrated in Figure 1. Here there is represented an object point 0 lying in the margin of the field. Instead of the lens forming a point image of 0, it forms as the nearest approach to it an ellip- tical spot of light at 0'. If we explore the cone of light in the neighborhood of 0', we will find that it nowhere comes to a point focus. At the place marked t in the diagram the light seems to be con- centrated in a short line as indicated and, at another place, such as 5, it again seems to be concentrated into another line at right angles to the line at t. t is the focus for the meridian of the line marked t, and 5 is the focus for the corresponding meridian of the lens. "The phenomenon of the representa- tion by a lens of object point 0 as a pair of perpendicular lines is called astigma- tism. The distance from 0' to the center of the distance between t and 5 is the curvature of field for this angle. The astigmatic difference (distance between t and 5), and the curvature of the field will vary from point to point over the field depending on the angle of the field of view. The focus of all points t and 5 is a pair of curved surfaces which con- stitutes the image of the object plane. These surfaces are indicated by the dotted curves connecting t and s in the figure with the center of the image." Correction Methods Spherical aberration and astigmatism may be overcome by the use of dia- phrams with bright light, which cut off all but the central rays, but in this case distinctness is obtained at the expense of brightness. Again, spherical aberration may be reduced by using several very flat lenses instead of one thick lens. The most satisfactory correction, how- ever, can be obtained with anastigmatic lenses ground on a system of computed curves that hold the accuracy of the lens surface curvature to within a few mil- lionths of an inch. These lenses have similar refracting power throughout, which, under existing projection sys- tems, is necessary to give the most evenly projected picture. Chromatic Aberration The dispersive (spreading), power of lenses, which are considered to be made up of any number of tiny prisms which bend light, is responsible for chromatic aberration. Chromatic aberration causes images to be reproduced on a screen with fringes around them, particularly around titles when the background is de- cidedly dark in contrast to lighter cen- tral features. The serious defect of chromatic aber- ration, as the projectionist already knows, is most easily and quite effec- tively remedied by combining a conver- gent lens of crown glass with a divergent lens of flint, to form a convergent achro- matic lens; or, if the crown glass is di- Figure 1 [14] December 1931 INTERNATIONAL PROJECTIONIST 15 P ortraits No. 1 ^^^ ^m 1 11^, wKku Hi ■EhHL i^fli THAD BARROWS . . . who is rounding out his second year as President of Projection Advisory Council, and his seventy-second year (or so it seems), as President of Boston L. U. 182. Also, member of S.MP.E., Academy of MJP. Arts & Sciences, and of numerous exclusive Back Bay social clubs. Holds a paid-up card in the Alliance. Has been President of L. U. 182 for so long that even the gendarmes in Paris recognized the name when he flashed his card on them — despite the dim light of the sta- tion house. Used to be a jockey, but out- grew the profession. Parts his wavy brown hair in the center; likes the trot- ters and pacers; eats three apples daily, and receives initialled gold cigarette cases from comparative strangers. Is weighted down with honors, most recent of which is election as Captain of the Girls Team, of the S.S. Leviathan. A swell Local Union officer and an even better projectionist. vergent and the flint convergent, a diver- gent achromatic lens. The introduction of sound-on-film pic- tures, to a marked extent, and wide films, to a lesser degree, have caused the noticeable demand for anastigmatic lenses. Had it not been for these com- paratively recent innovations, it is doubt- ful if "corrected" lenses would have as- sumed the importance they now rate. With the advent of sound-on-film (which is now almost exclusively used), there arose the definite need for the undersize proportional aperture, to restore sym- metry to the odd-shaped screen image caused by the presence of the sound track on the film. The undersize aperture, in turn, necessitated the use of a lens with a shorter focal length, to give magnifica- tion to the image and at least bring it up to an acceptable size. With the reduced aperture and shorter focal-length lens there was a loss in bril- liancy and an increase in aberration; following the formula that the shorter the focal length of the lens, the greater the aberration. To insure less aberration and more brilliancy, brought about by loss of light through the reduced aperture and the increased light requirements of the per- forated screen used in the presentation of sound pictures, the improved type of "corrected" lens has been introduced that not only copes with spherical aber- ration and astigmatism, but, further, pro- vides an improved image quality for standard film, with a flatness and bril- liancy of field that is comparable with, if not superior to, the images obtained in the "old days" of the larger aperture and longer focal-length lens. Short Focal Lengths Regardless of aperture size, if neces- sity demands it, larger pictures can be projected with "corrected" lenses from standard film. And, despite such high magnification, short focal length lenses of from 3V2 to 2-inch focus give a qual- ity image that is well defined and char- acterized by commendable flatness of field. The projectionist is, however, more directly concerned with the already ex- plained manner in which "corrected" lenses cope with the effects of the under- size aperture and short focal lengths re- quired by sound-on-film projection. If he will make a study of these lenses and give them a fair trial he will no doubt find, as the writers have found by actual tests, that in the majority of cases they project a better sound-on-film picture. This, then, is broadly the why? of "corrected," or anastigmatic, lenses. Mark Time on New 3x4 Aperture ^T^HE original specifications of -i- .615 by .820 for the proposed new standard 3x4 proportional aperture are not likely to stand, according to developments of the past month. Numerous confer- ences between Lester Cowan of the Academy and representatives of projection and technical societies in New York emphasized the need for reconciling established theatre practices with any proposed new aperture size. The consensus of opinion among projection representatives, men who are in a position best to un- derstand the needs of the theatres, is that dimensions .590 x .825 would be most satisfactory to all concerned. An 18° mean distor- tion angle has been advanced as most desirable, although in the ab- sence of definite data this estimate is necessarily arbitrary. PROJECTOGRAPHS Wallace G. Crowley DINNER on a tray in my room and not alone — that's luxury in some countries, but not to me on matinee- days . . . it's actual necessity . . . the room I referred to is the projection room . . . the company, another projection- ist .. . did you ever try making a change-over while balancing a piece of pie in one hand? ... A real projection- ist is one who will in an emergency sacri- fice the pie . . . That's a tough yard- stick to measure up with . . . Saturdays and Sundays are our week-days wherein we work longer hours . . . It's great get- ting to watch the happy crowd making their ways to seats during a Sunday night intermission . . . You sort of realize that we are not one of the happy majority . . . We lead a life far apart from that of the butcher, plumber, clerk, or busi- ness man . . . While they play we work . . . Their amusement is our toil . . . Their idly-dropped fifty-cent piece is the source of our very existence . . . Ever count two rows of heads in a balcony and remark that there sits my week's pay? Have you ever regretted the necessity of being away from home Sundays, holi- days and evenings? ... No idle chat- ting over the back fence with your neigh- bor on Saturday afternoon . . . No Sun- day stroll through the park with the wife and kids, watching the array of happy humanity on parade . . . When the Thanksgiving turkey is only half-eaten you apologize hastily to the guests and hurry away . . . While the kids are happy with their new toys playing around the Christmas tree . . . One of them pauses and shouts, "Ma; where's Daddy?" The answer comes with just a touch of sad- ness in the tone, "He's gone to work at the show, dear" ... If all this could apply to you — and you have no regrets or self-reproach, then you'll be a real suc- cess in this show business . . . you heart- less wooden Indian. Sitting at the bedside of a dying pro- jectionist who said that he was glad he had been able to bring happiness to so many people ... in the strained mock hospital gaiety the remark went unnoted . . . days later, after it was all over, it dawned on me what he really meant ... he couldn't have lived in vain; his daily work was to cause lights and shad- ows to lull thousands of restless world- weary minds into forgetfulness — oblivioni for a time — gained by staring at his handiwork on the screen. They lived- for a time with kings and queens — ^re- turned to reality only when the curtain closed and the lights came up. They go their various ways better beings because of their brief respite from reality. 16 INTERNATIONAL PROJECTIONIST December 1931 THE CHATTANOOGA TIMES: CHATTANOOGA, TENN.. SUNDAY, NOVEMBER 29, 1931. MOVING PICTURE PROJECTIONIST AND HIS WORK JVIust Be Trained in Use of Delicate Machine and Whatnot. "W BT R, M. COOKE. F-ONDERPUL direction; remarkable photogra- phy; perfect diction." These and similar expressions are frequently heard from patrons of the present-day movie 5how, But has it ever occurred to niovie :fans that, in a little room far above "the audience which thrills at the out- standing features of a screen produc- tion, are men upon whose shoulders, after ail, rest the success or failure oi the performance? Nerves a-tingle, eyes, ears and wits attuned to detect the slightest imper- lection, the projectionist, or operator, has put into the entertainment all the result of years of practical training, "technical study and physical effort ^hich are his contribution to this one ■of Ir'iie most remarkable industries of *li time . A projection engineer, he likes to ■fee called, and when those authorities -■yho are making a life business of pre paring the film for projection refer tc his contribution as a specialized art the former lowly button-pusher ■swells with pride and often delights 3n regaling the, layman with a dis- ■Scitation upon the many technical Jjoints of his profession. But, as indicated above, not always Tvas the projectionist regarded as a Titol cog in the presentation of mov- ing pictures. In the early days of the nickelodeon he sat in a cubbyhole, as president was made in a telegram which was sent to all locals on December 9th. Two days later President Elliott, in a general letter to all locals, reviewed the sessions of the Executive Board and confirmed the acceptance of Canavan's resignation. Elliott's letter stated that the Executive Board was very reluctant to accept Canavan's resignation and did so only when it became evident that Canavan would not change his mind. Elliott further pledged that he person- ally and the members of the Executive Board would do everything possible ta promote the interests not only of each Local unit but also of every individual member. An extension of these remarks anent future policy is expected to be forthcom- ing shortly after the first of the year. Elliott spent the holidays at his home in Cincinnati. Although Canavan has indicated his intention of returning to his former home in St. Louis on or about February 15th, there are many conflicting reports abroad as to his plans for the future. Canavan has disclaimed any intention of participa- ting further in labor work, either for organized unions or for employers. MATHEMATICS FOR THE PROJECTIONIST Siegfried S. Meyers INSTRUCTOR IN PHYSICS, STUYVESANT HIGH SCHOOL, NEW YORK f ■"! HE motion of the film in its pass- I age through the projector is the -^ result of careful design of gears and shafts. Gears vary in size, but in a gear train intended to perform a certain work, each gear bears a definite rela- tionship to the others. Let us consider a hypothetical case of gear mechanism: Problem : Suppose we desired to drive a certain disc at a speed of 60 revolutions a min- ute by means of a direct-current motor the normal speed of which under a load is 1,800 revolutions per minute. Solution: This speed reduction may be accom- plished by any one of several methods: 1 . Couple the disc directly to the motor shaft, and reduce the speed with a series rheostat; or 2. Couple the disc directly, and reduce the speed by applying mechanical opposition to its rotation ; or 3. Couple the motor to a small gear which meshes with a larger gear. Of these three possible methods, the latter is the most economical as well as most practicable; the others having in- herent power losses. Since the motor makes 1,800 revolutions in one minute, and we desire to reduce this number to ■60, the ratio is 30-to-l. Thus, the small gear must make 30 times as many revo- lutions as the larger gear which carries the disc. To accomplish this work two gears are so machined that the larger one will contain 30 times as many teeth (not 30 teeth more), as the smaller one. If the small gear has, say, 10 teeth, the larger gear must have 300 teeth to produce the Tequired speed of rotation (Fig. 1). The Worm Gear Where precision adjustment is re- quired, a worm gear is most satisfactory. A worm gear consists of a threaded shaft which meshes with a cog-wheel. This ar- Figiire 2 rangement is used where large ratio re- ductions are required. Where 14-to-l reduction is required, it is quite easy to machine two teeth on the worm and 28 teeth on the cog-wheel. In such a case it would require one complete revolution of the worm to make the shaft move 1/14 of a revolution. The rack and pinion, which is com- monly employed to focus lenses, uses the worm gear principle (Fig. 2). The Graph In optics the formula is given: candle-power Intensity = distance' Reducing this to symbols : c.p. 1= d' where : d' = distance X distance c.p. = candle-power Let us consider the meaning of d'. Assume a 32-candle-power lamp is mounted one foot removed from a screen. The brilliancy or intensity of illumination of this screen is 32 foot-candles. If we should move the lamp twice as far away, or 2 feet, the illumination on the screen would naturally decrease. The distance now being twice as great, we might say offhand that the illumination would be reduced by one-half. Such is not the case, for it has been proven that the intensity does not vary inversely as the distance but rather varies inversely as the square of the distance (distance multi- plied by distance). Using numerical values, let us make a table of illumination as compared with distance : Intensity (foot-candles) Distance (feet) D= Figure 1 32 1 1 8 2 4 2 4 16 'A 8 64 We may make a graph showing these values, so that we may ascertain the in- tensity at any distance within the limits of the graph (Fig. 3). In reading this graph it may be seen that the intensity falls off quite rapidly as the distance from the screen becomes greater. If we were to continue to move further away, the intensity would be so small as to be negligible. The equation used to arrive at this conclusion is said to be a "second degree equation," which means that one of its terms varies as some other term whose numerical value is squared or multiplied by itself. This equation is frequently referred to as the "law of inverse squares." In projecting an image upon a screen it is common experience to observe that the image may be made larger or smaller by simply adjusting the distance of the object from the lens. The size of the image is equal to that of the object when both the object and the screen are equi- distant from the lens. This relationship is expressed by the following equation: Lo Li Do Di Where: Lo = length of the object Li = length of the image Do = distance of object from lens Di = distance of image from lens Problem : Substituting numerical values in the equation, let us consider the placing of a piece of film 1 inch in length before a lens at a distance of 4 inches. The screen is, say, 50 feet away. What is the length of the image? Solution : Lo Do Li Di Li 50X12 fa- 1 1 — 1 1 — 1 1 1 r 1 [ 1 1 — 1 — 1 1 — 1 ^.o ^^ Kg ."^ ^ > !2 T '^1 Nb iH r-~. ' — ^ a _ ^ I— ^ , ' 1 ■■~- ' — •< O i f A . a. Figure 3 [23] 24 INTERNATIONAL PROJECTIONIST December 1931 o^ WWV ammeterW y Figure 4 4 Li = 600, therefore, Li = 150 in., or 12.5 feet, Ans. Suppose we made the distance between the film and the lens one-half as great. Then: 1 2 Li 50X12 2Li = 600 and: Li = 300 in., or 25 feet, r Although the linage is now twice as large as previously, the intensity of il- lumination is one-quarter as great, fig- ured according to the law of inverse squares. Conversely, if we double the distance of the object from the lens, the magnification will be one-half as great, but the intensity of illumination will be four times greater than previously. Electric Power It is desired to calculate the cost of running a %-h.p. electric motor for four hours per day at the rate of five cents per kilowatt hour for a period of thirty days. Formula: 1 h.p. = 746 watts, or 1 h.p. = .746 kilowatts (since kilo = 1,000) Steps: .746x4hrs. = 2.984 kilowatts daily 2.984x30 days = 89.520 kilowatts monthly 89.520 X. 05 = $4,476, monthly cost An electric lamp is rated at 500 watts. How large a fuse will be necessary to carry the normal current for this lamp in a 100- volt circuit? Solution: i Watts = volts X amperes watts Amperes = volts Amperes = 500 100 5 amps. A storage battery rated at 100 ampere hours capacity is completely discharged. How much resistance must be inserted in series with the battery and a 100-volt direct current line so that the battery will charge in 25 hours? Solution: (1) To deliver 100 amperes in 25 hours we must charge at the rate of 4 amperes an hour. (2) By ohm's-law: Resistance 100 (3) R volts amperes 25 ohms. This answer is approximately true be- cause we have neglected the resistance of the battery itself (Fig. 4). Vaci Tub( We often encounter the term "charac- teristic curve of a vacuum tube." This curve is of great value in understanding the normal functioning of a vacuum tube, and of far greater value when the tube does not function normally. We all know, of course, that a heated filament emits 'electrons which may be drawn over to a metallic plate that is connected to the positive side of a high voltage battery. When a coil of wire (grid), or some other metallic shape is inserted between the filament and the plate, this grid can be made to control the number of elec- trons which reach the plate. When the grid is given a positive charge by connecting it to a low-voltage "C" battery, electrons will leave the fila- ment at a faster rate than when the grid has no charge at all. The reason for this is that the electrons coming from the filament bear a negative charge, and, since opposite charges attract, these elec- trons more readily leave the filament. Conversely, since like charges repel one another, a negatively-charged grid will repel the filament electrons, and will pre- vent them from leaving the filament. By connecting a voltmeter across the "C" battery, and by inserting a mil- liameter in the plate circtiit of the vacuum tube, we can ascertain how many volts on the grid are required to cause 90 VOLTS 180 VOLTS 230 VOLTS Figure 1 a particular current change in the plate- circuit. This ratio is known as the mu- tual conductance factor of the tube (Fig.. 5). If we plot several values of grid volt- ages on one axis, and corresponding values of plate current on the other axis, a curve is obtained which graphically conveys the characteristic curve of the tube (Fig. 6). It will be noted in the accompanying illustration that the curve is not linear. By this is meant that for each unit of grid voltage change there is no corre- sponding unit of plate current change throughout. At the lower left of the curve we find it rather flat; then more steep in the center; and finally flat on it3. top. The middle, or straight part of the curve, is most useful in amplifier circuits, for in this case, any small change in grid voltage produces a uniform change in plate current. Since the plate circuit feeds the loud speakers, a small voltage is impressed upon the grid of the first tube, which produces a large plate cur- rent change. This current passes through a resistance which provides a voltage drop for the grid of the next tube, and so on to the final stage. Overall Amplification The term overall amplification refers, to the gain in voltage which a given am- plifier is capable of producing when a small voltage is impressed upon the grid of the first vacuum tube. Consider the following problem: Assume the output of a photo-electric cell to be 1/lOth volt. This is fed into the grid of a tube the amplification factor of which is 30. If three tubes are coupled in a resistance-coupled amplifier, what will be the overall amplifications? Sfu?/ ^ — - — ' — ' ^2: <> dS'"" Xa Y ^^'« / ^^' fi^^ ^A y, y^ ^„..^ 5 A > } i ' < -) t 2 \ « i i NEGATIVE Figure 5 GRI£> VOLTS Figure 6 POSITIVE- December 1931 INTERNATIONAL PROJECTIONIST 25 A SERVICEMAN'S DIARY ADD to your list of "Things We Never Knew Before" (and, in fact never even suspected), the following interesting bits of information gleaned by Editor G. K. Rudulph for his RCA Photophonews. The stories had their inception with servicemen, yet at this season of the year we have charitable feelings even toward servicemen. Witness: "Red rust found on sound head parts in the theatre at Port Orchard (Oregon), was attributed to salt sea air. However, other equipments — also at seaports — were not similarly affected and an investigation was made. Lubri- cating oil containing acid was eliminated when it was found that bright steel parts in the motor drive side of the heads were not rusted. It was noticed, in fact, that all corrosion occurred on parts exposed and liable to contact by the projectionists' fingers in course of 'threading-up', etc. A litmus test of the operator's skin showed excessive acid perspiration." A serviceman in the Dallas District reported changeover relay, tube sockets, terminal strips, bearings, etc., in one theatre had been penetrated with dust. It was found, as the cause, that the cement floor in the booth perpetually flakes off in dust. Another case reported the corroding of all electrical contacts. After an investigation it was found that the exhaust gasses of automobiles parked outside the windows entered the room and thereby became the corrodent. Solution: 30 X .1 v. = 3 volts (after 1st tube) 3 v. X 30 = 90 volts (after 2nd tube) 90 V. X 30 = 2,700 volts (after 3rd tube) In brief, the overall amplification of any amplifier is determined by the following formula: ^ ;_ A = e X (/i)n A = overaH amplification e = impressed voltage fi = amplification factor n = number of tubes The term "p." means that the amplifica- tion factor of the tube is multiplied by itself as many times as there are tubes. For example: (1) With .1 volt and with one tube, the formula gives us: A = .1 X 30^ A = 3 volts (2) With .1 volt and with two tubes, we get: A = .1 X 30' A = .1 X 30 X 30 A = .1 X 900 A = 90 volts These calculations could go on for a great many tubes. In calculating for many tubes, however, one must take into consideration tube noise and other ex- traneous capacity and coupling effects which introduce elements of noise which are amplified along with our original voltage. Voltage Drop A power supply delivers 500 volts of direct current which has been properly rectified and filtered from the A. C. sup- ply. Problem : A 30,000-ohm voltage divider is con- nected across the output. At what points may taps be taken so as to produce volt- ages of 90, 180, and 230 volts, respec- tively (Fig. 7). (Hint: The larger resistor will have the greater voltage drop.) Solution : 90 180 230 500 (1) H h = ;or 500 500 500 500 9 18 23 50 (2) H h = 50 50 50 50 Since there are 50/50th parts in 30,000 ohms, each l/50th of the resistor is equivalent to 600 ohms. Therefore: (1) 9 For 90v: x 30,000= 5,400 ohms (2) For 180 v: (3) For 230 v: 50 18 50 23 X 30,000 = 10,800 " X 30,000 = 13,800 " 50 50/ /50 {To be continued) 30,000 " Harland Holmden, B. A. of Cleveland Local Union 160, has been appointed seventh vice-president of the LA. to fill the vacancy made by the resignation of President William F. Canavan, Holm- den's appointment is effective immedi- ately. TELEVISION SECURITIES THE following summary concerning several of the leading television com- panies is being distributed by a New York investment securities house which specializes in television securities, and will undoubtedly prove helpful to those interested in this art: Jenkins — Incorporated in 1928 to pro- mote ideas and patents of C. Francis Jen- kins. Controlled at present by the De Forest Radio Co. Company is offering a television set for the home and has been operating television broadcasting studio for some time. Stock was sold in 1928 for $10 per share. Now on the N. Y. Produce Exchange and selling for about $2.50. Standard — Company has taken over the Insuline Corp. of America which manufactures electrical parts and is of- fering television home sets priced from $37.50 up. Capitalization is for 1,000,000 shares of $1 par value. Insuline Corp. reported profit for nine months ending July 31, 1931 of $38,653.75. Factory is located at 23 Park Place in New York City. Stock is offered at $2.00 per share. Baird — Company is an English com- pany which is offering a television home set and operates a television broadcast- ing studio. A recent announcement wa& made that the company intends to offer a set in the United States to retail for $25.00 and has made arrangements for broadcasting with station WMCA in New York. Shares are listed on the London Stock Exchange and can be bought here for about 85c. Telephoto & Television — Incorpor- ated in 1929 as the Telephoto Corp. to manufacture photo-electric cells and tele- vision tubes. Company has been supply- ing its products to Paramount-Publix, Universal Sound System, and others. The photo-electric cell, called the "eye" of television, has many other uses which gives the company several outlets for its sale. Company can supply kino-lamps and cathode-ray tubes for television re- ceiving sets. Stock was offered recently for $2.50 per share and is now selling for $3 on the N. Y. Over-The-Counter mar- ket. President is Mr. Nicholas Fabian, who was President of the Televocal Corp., manufacturing radio tubes, which company was bought by the banking firm of Lehman Bros, in 1929. Shortwave & Television — Company has its headquarters in Boston. Mass. Offers a television kit and set and oper- ates a broadcasting studio. Also sells a shortwave radio set. Stock is on the N. Y. Produce Exchange selling at about $2.00. The television field generally has been very quiet for the past six months, with the exception of the recent Sanabria dem- onstration in New York. AMERICAN LABOR MOVEMENT'S 50TH ANNIVERSARY A review of fifty years of progress of the American Federation of Labor, with which the International Alliance is affiliated and in the councils of which it plays an important role David Levinson THE American Federation of tabor, of which the I.A.T.S.E. is an af- filiated organization, is this year celebrating its fiftieth anniversary. It was in 1881 — from which year the Fed- eration officially dates its birth — that a group of labor leaders, dissatisfied with the loosely organized status of unionism in the United States, called a convention at Terre Haute, Indiana, to remedy the situation. At this convention, attended by large bodies of delegates from St. Louis, Cleveland, Chicago, and other Western cities, with Pittsburgh the only Eastern city represented, plans were made for a more representative conven- tion, to be held the same year in Pitts- burgh. At Pittsburgh, with John Jarrett, at that time president of the Amalgamated Association of Iron and Steel Workers, as temporary Chairman, the Federation of Organized Trades and Unions of the United States and Canada, representing 262,000 workingmen, was formed. In attendance at this memorable gathering were 107, representing eight national and international unions: forty-two were from local trade unions; three were from dis- trict assemblies of the Knights of Labor, an organization which had been very ac- tive as a forerunner of the Federation of Organized Trades and Unions of the United States and Canada. The organization which had been formed at Pittsburgh existed for but a short while, and finally faltered, prin- cipally because of the lack of funds. But, if this organization accomplished nothing else, it did serve to introduce to the public a man who was later to be proclaimed the greatest labor leader this country, if not the world, has ever had. This man was Samuel Gompers. Rise of Gompers At the third convention of the Federa- tion of Organized Trades and Unions of the United States and Canada, held in New York in 1883, Samuel Gompers, who bad come into prominence in national labor circles after having done heroic work with the Cigar Maker's Union in its fight against unfair conditions in that field, was elected chairman of the organi- zation and of its important legislative committee. SAMUEL GOMPERS "Grand old man" of the American Labor movement From 1883 to 1886, very little of im- portance was written into the history of unionism in the United States. But in 1886 the spirit that had been born in 1881 and subsequently had become dor- mant, was revived. The guiding geniuses and the masses of workingmen again felt the need for the display of a solid front of unionism. The most important step towards the realization of this need came at the Co- lumbus, Ohio, convention, in December, 1886. At this convention the old Federa- tion of Organized Trades and Labor Unions amalgamated with large groups from many other unions, and thus the American Federation of Labor, represent- ing some 300,000 members in good stand- ing in twenty-five organizations, came into being, with Samuel Gompers as its first president, a post which he held down to his death in 1924, with the ex- ception of one year. Federation Gains To what extent there have been gains by organization since the inception of the Federation fifty years ago is clearly shown by a review of some of the work of the A. F. of L. given by the executive council to the 51st Convention. This report discloses that the organization of [26] the American Federation of Labor admit- tedly gave strength to the workers in 1881. From 1886 to 1890, the 8-hour day drives brought added leisure, cutting working hours per week from 63 to 58. From 1899 to 1904, membership in the Federation increased from 349,122 to 1,676,000, and immediately workers gained in leisure and better pay. In the five years of membership gain, average wages rose 14 per cent, and hours were shortened by nearly two per week. From 1904 to 1908, despite the busi- ness depression, labor still held its own. From 1909 to 1914 came another period of growth, during which time member- ship increased from 1,483,000 to 2,021,- 000, and gains in wages and hours were greater. Wages increased by 13 per cent, and hours were shortened by 1% a week. After 1913 began the wartime growth of trade union membership; membership was doubled and the increase in real wages was more than in any other five years of rising prices. Then came the post-war depression of 1921. Unions lost membership, wages de- clined, and the hours were lengthened slightly. Until the beginning of the 5-day week drive, there was practically no further gain in leisure. Wage losses were finally won back, but the wage level has not yet risen above the 1920 high. In fifty years altogether, workers have gained 15 hours leisure per week, and increased their buying power $13 a week; hours of work have decreased from 63 a week in 1880 to 48 a week in 1930; wages per hour increased from 19 cents in 1880 to 72 cents in 1929. Buying power of average wages in terms of 1929 dollars, increased from $18.80 to $34.75 in 1929. Present Condition The present organization structure shows that for the fiscal year ending August 31, 1931, there was a total mem bership of 2,889,550. This membership is distributed among 28,229 local unions in the 105 national and international unions with a membership of 2,875,019, and 334 local trade and federal labor unions directly affiliated with the Ameri- can Federation of Labor with a member- ship of 14,531. Today, as the 50-year-old Federation faces an era of depression and changing December 1931 INTERNATIONAL PROJECTIONIST 27 conditions, it has two of the most signifi- cant and perplexing problems in its his- tory to deal with: wage reductions and unemployment. The American Federation of Labor firmly believes that maintaining wages is a preventive measure. "Workers' buying power must be maintained so that the demand for goods will be kept up and employment may not fall to any lower levels. It is essential also to maintain the American living standard, for wage levels recover slowly. The wage liquida- tions of 1921 retarded workers' progress by more than eight years. For by 1929, wage earners had not entirely regained the 1921 losses." "Falling wages have an effect on busi- ness comparable to falling prices. Fall- ing prices start a competition in price reductions, each firm trying to secure business by cutting prices a little below others. Thus, the price is driven down, in some cases even below production costs. At such times purchasers hold back their orders as long as possible to take advantage of the lowest price. Wage reductions would start a toboggan slide of wages similar to prices in the last year and a half. Though wages were re- duced below the minimum living stand- ard, customers would still put off their orders to wait for further reductions. Both commodity and labor markets would be thoroughly disorganized. Such a pol- icy would retard business recovery." A. F. of L. Program To meet the crisis that is expected to be created by at least 7,000,000 people being unemployed this winter, the Fed- eration advocates, besides the mainten- ance of wages, the following program: 1. Shorten work hours. Dividing work hours will provide work for more men. 2. Assure employment to minimum work ' forces. By assuring employment to minimum work forces some 20,000,000 wage-earners could plan their purchases with confi- dence over a definite period. 3. Each employer take on additional ivorkers. If all employers were to take on an average of two workers each, all but 1,000,000 of the unemployed would be given work. 4. Create work through public building. It is estimated that work was created in 1930 for 75,000 men in public build- ing in addition to those already at work, and for 150,000 men in the industries supplying materials for this work. If every effort be made to create work through public construction this coming winter, it should be possible to give work to over 100,000 in addition to those now employed. 5. Strengthen employment agencies. Attention should be concentrated on building up the present system of em- ployment bureaus and supplementing it where necessary. Local communities must undertake the main effort, but the federal and state governments can sup- port and encourage, and undertake the essential function of coordination, put- ting local bureaus in touch with needs in other parts of the state or country. 6. Keep young persons in school to pre- vent their taking jobs from older men and women. Every effort should be made to keep boys and girls in their teens in school. Not only will their efforts to secure work take jobs from older men and women, but they will find it difficult to get work. 7. Give preference to workers with de- pendents. Employment should be given workers whose wages must maintain dependents. Fathers of families and workers who must support dependents should have TWO LEADERS IN THE A. P. S. George Edwards, of New York, past Supreme Preiident, and Frank Seavier, of SaUi Francisco, who is slated to be the next president prior consideration when additional em- ployees are needed or when personnel is being reduced. 8. Give financial relief from public and private funds. Without question there will be millions this coming winter who will depend for existence on charity. Funds should be used primarily to furnish work rather than relief work wherever possible. The collection and administration of funds for relief purposes is of utmost import- ance to Labor, and Labor, with other groups, should be represented on boards responsible for this work. The I. A.'s Record The affiliation of what is now the Inter- national Alliance of Theatrical Stage Em- ployees and Moving Picture Operators of the United States and Canada with the American Federation of Labor has been a long and active one. Chartered by the Federation July 20. 1894, as the Na- tional Alliance of Stage Employees, the organization retained this title until Sep- tember 25, 1902, when, at the 10th annual convention, "General Secretary-Treasurer Lee M. Hart addressed the Convention on the necessity of the National alliance making application to the American Fed- eration of Labor for a change of name and charter from a National Alliance to that of an International Alliance of The- atrical Stage Employees." Following Mr. Hart's address, a mo- tion was unanimously carried to have the American Federation of Labor change the name of the National Alliance to that of an International Alliance of Theatrical Stage Employees "with trade rights of all theatrical mechanical work and con- struction that in any way has to do with the successful production and rendering of any theatrical or operatic entertain- ment." Except for the issuance of a duplicate charter in 1912, there were no changes in the title of the International Alliance of Theatrical Stage Employees until 1929, when the International Alliance of The- atrical Stage Employees and Moving Pic- ture Machine Operators superseded the latter organization. The strength and interest of the LA. T.S.E. in Federation affairs is concretely demonstrated by an inspection of the table of voting statistics of the affiliated unions of the American Federation of Labor. For the years 1923 up to and including 1931, it is shown that the In- ternational Alliance of Theatrical Stage Employees and Moving Picture Opera- tors of the United States and Canada, now ranks 32nd in voting strength among 107 organizations, and that since 1923, the I.A.T.S.E. has shown a very favor- able standing, while other groups have failed to progress or retain the growth they had once obtained. 28 INTERNATIONAL PROJECTIONIST December 1931 FROM FOREIGN FIELDS New French Devices A PROJECTOR provided with a means for directing air on the film during projection. Three nozzles blow air on the film at the gate and on each side thereof. ... A film splice for re- pairing breaks in films. The two ends of the films are cut to form convex and concave ends, which are overlapped and cemented together. ... A system syn- chronizing an orchestral accompaniment and motion pictures, which includes a separate film, synchronized with the pic- ture film, having notes on it which may be read by the orchestra leader. . . . A sound film on which the area for sound is indicated by a tint, or the like. A projector that will allow better sound production by eliminating vibra- tion, and do away with intermittent mo- tion of the film. Called the "Universal" projector. ... A four-color process in which a beam splitter is placed behind a revolving filter carrier. The revolving carrier has two different filters which are alternately in the beam. The beam split- ter has two' different filters in the two beams, thus providing four different filter combinations. New English Devices AN apparatus in which, while one or more films are being projected, the parts of the same films that have already been projected or other films are being rewound. ... A reflecting device which laterally reverses the projected image provided in the beam of a projector hav- ing in combination with it a sound re- producing unit using a photographic sound record on the film. Projection from the rear of the screen without chang- ing the position of the film is thus accom- plished. ... A projector provided with electric contacts normally held open by the film and by a belt transmitting mo- tion to the film feed mechanism. Break- age of either the film or the belt will cause the projecting lamp to be extin- guished, the lights in the theatre switched on, and the motor stopped. A method of sound picture production which comprises an acted performance concurrently with a phonographic rendi- tion of the sound part incident to the performance. The photographic and sound apparatus being perfectly syn- chronized. The sound record used may thus have been prepared by any desired person or musical organization. New German Devices A PROJECTOR provided with a driv- ing mechanism which converts con- tinuous movement into intermittent mo- tion; brought about by a particular form of chain drive. ... A projector in which the film runs continuously except at os- cillating gate, where movement of film is intermittent. The speed of the movement during the period of motion is faster than the movement of the film at take-up sprockets. ... A safety screen made of a sheet of glass containing on its surface positive or negative cylindrical lenses. ... A projector case which may be opened up and contains a screen at one end. An optical means in a sound projector for picking up the sound irrespective of the location of the sound track on the film. An arrangement which avoids fringes in the projection of color pic- tures by a process using lenticular films. ... A support for a camera to al- low the camera to be shifted to different positions for taking two successive pic- tures for stereo purposes. ... A method of printing sound records on narrow film which includes perforating the narrow film to correspond to the wider film. . . . A projector in which, when one film is exhausted, the end of the' film is auto- matically attached to the trailer of the exhausted film and threaded through the machine. Russian Color System NIKOLAI ANASHIENKO, Russian in- ventor, is reported to be working on a new system for colored pictures. The idea is claimed to be a radical innova- tion but at present is being held back be- cause of the presence of flicker in re- production. Anashienko's method employs a revolving disk and two filters. Pictures are photographed through a single lens and the camera with all associated appa- ratus is not in the least complicated. Wage Scales Abroad AS a result of intensive agitation, French projectionists have secured an increase in salary. Theatre projec- tionists have agreed to take 230 francs (approx. $9) a week for theatres open- ing three times a week, and 550 francs (approx. $21.50) a week for a six-day week. Each supplementary performance will be paid for at a rate of 50 francs (approx. $2) per time. Our British Friends Dear Mr. Finn: May I impose upon you by asking you to extend, through the medium of Inter- national Projectionist, to our brother craftsmen in America and throughout the world the best wishes of the officers and directojrs of the Guild of British Kinema Projectionists and Technicians for a very prosperous airtd happy New Year? At the same time I should like also to express the thanks of this organization to American projectionists for doing in such splendid fashion so many worthy things which have been of such great help to us here in Eng- land. Stanley T. Perry, President, Guild of British Kinema Projec- tionists and Technicians. Theatre operators in Mexico are also having their troubles these days as a re- sult of projectionists forcing the closing of houses when their wage demands were not met. The owners replied that the existing rate of wages was already too high: 18 pesos (approx. $8) a day for first-class men, and 12 pesos (approx. $5) for assistants. These figures, while not high for projection work, are re- garded as "big money" in Mexico where the average family income is about $25 weekly. German Sound Installations THERE were 1,132 Klangfilm, Tobis, and Gaumont reproduction ma- chines installed in German cinemas by October 1, 1931. Of this number 561, or 49 per cent, were with single projector and 571, or 50 per cent, were with double projector. Of the total number 322, or 28 per cent, were of the film and disk inSthod; 762, or 64 per cent, were film bhly; and 48, or 4 per cent, were disk only. Forty-five per cent of the total number of machines are of the sound on film type with single projector. These are installed chiefly in small-sized houses, of which there are a great number in Germany. 'Something from Nothing' A METHOD of producing "sound out of nothing" by drawing and photo- graphing a sound track has been per- fected, after many years' experiments, by Rudolph Pfenniger, of Emelka. The sound track along the side of the film is artificially drawn and then photographed, the results being similar to those of the sound recording apparatus. This method will be employed in the Emelka sound short "Die Tonende Handschrift" ("The Sounding Handwriting"). | Superimposing Film Titles ACCORDING to a report from Oslo, Leif Eriksen, of the Norweigian branch of an American company, has in- vented a process for superimposing titles on film. A great improvement has been brought about by this invention, it is stated. Eriksen has patented his method, but has not as yet disposed of the patent rights. It is understood that the process consists of printing the titles on the film with a certain acid so that the printing appears in white, showing in white on the screen also. Of course, the film can be run through the projector in exactly the same way as before, as the printing does not interfere with it in any way. December 1931 INTERNATIONAL PROJECTIONIST 29 NEW ATTACHMENT SOLVES SHIMMING PROBLEM Non-shimming apparatus has been avail- able for some months now, yet we have received recently many requests for in- formation relative as to how best to over- come this problem. The apparatus here- in described may be secured from Inter- national Projector Corp., New York, which company designed and manufac- tured this unit following the recommen- dation of the Projection Practice Com- mittee of the S.M.P.E.—Edhor. SHIMMING has been a very serious problem since the introduction of sound reproducing equipment, but is only prevalent in connection with that equip- ment known as the D-Spec. attachment. This was the first attachment made and ■consideration was not given at that time to the varying tolerances allowed by the manufacturers of the projector prior to the advent of sound-on-film. It was pointed out that it was not necessary to machine rough castings to which nothing was to be attached when projecting silent pictures, but great dif- ficuky was experienced when sound at- tachments were added to these unma- chined surfaces. It became necessary to use shims running all the way from one- eighth of an inch down to one-thousandth of an inch on the several corners of the mechanism in order to properly line up the projector mechanism with the sound equipment drive. Great Time Loss Obviously, where a breakdown oc- curred during the running of a show, several hours or more would be required to adjust a mechanism. Since the major- ity of theatres in this country are equipped with only two sound-equipped projectors, it meant that the theatre where the breakdown occurred would be left with only one projector to run the show, until the repair on the other pro- jector had been completed. This, in turn, made it impossible to give a smooth per- formance. The matter of solving this difficulty was put up to the manufacturers of both sound equipment and projectors; and an attachment has now been developed NOTES from the SUPPLY FIELD which eliminates the necessity for shim- ming. This attachment is entirely flexible and by its use the difficulty of replacing mechanisms on this very old-type sound attachment is entirely surmounted, so much so, that mechanisms may be readily changed within fifteen or twenty minutes. For D-Spec. Equipment Figure 1 shows this new attachment. It is only necessary to remove the gear retaining yoke from existing D-Spec. at- tachments and replace it with the new yoke and idler gears shown in the pic- ture. This yoke is self-centered on the driving spindle for the projector mechan- ism, and it is only necessary to insert the spindle in the bearing and push it through into the hole provided in the mechanism to receive it. The yoke is then securely locked on the frame of the sound attachment and the bracket carrying the idler gears is then so ad- justed as to eliminate lost motion be- tween the gear teeth and the driving unit. The idler gear bracket is then securely locked in place by means of lock nut M. Attachment Method Figure 2 shows the assembly dis- mantled. At A is the flywheel always pro- vided with the sound attachment; this is readily removed by taking out three screws. At B are the lock nut and washers for attaching the new yoke to the sound attachment; at C are the driving gears connecting the mechanism through the idler gears G and H to the main driving gear on the sound unit; at D is the spindle which slides into the hole M in the mechanism and upon which the assembly C revolves; at E are the three screws for attaching protecting cover L after unit is assembled; at F is the self- aligning yoke which carries the idler gear assembly; at G and H are the idler, gears; at / is the adjustable bushing to take out end play in assembly C ; and at K is the adjustable idler gear bracket. No shimming is required when this new attachment is used, regardless^ of the age of the projector on which it is mounted, and it is felt by the designers that this unit satisfactorily solves the problem of replacing mechanisms where the old type sound attachment is used. This attachment is now available from International Projector Corp. NATIONAL CARBON COMPANY REDUCES PRICES PROJECTOR carbons will be cheaper after January 1, according to an an- nouncement of the National Carbon Co., and extra length will be added to one of the high intensity series. The new prices of the various sizes follow: The 12 mm. x 8 SRA size has been priced at $70 instead of $75 per thou- sand; the 8 mm. x SRA will be reduced from $95 to $80 per thousand; and the high intensity 9 mm. x 20 will sell for $245 instead of $325 per thousand. Two inches have been added to the 13.6 mm. X 20 {now 22) high intensity carbon, the price of which will remain at $400 per thousand. This size is extremely popular for high intensity work. The new SRA series carbons constitute a major advance in carbon performance; while the introduction of the pre-cratered carbon has won the approval of projec- tionists everywhere. DEVELOP A NEW PAPER LENS WIPER THE Howland Company, Inc., of New York City, is reported to have developed a new paper lens wiper which is said to possess all the softness and smoothness of cloth, is not abrasive, and will clean a projection lens better than anything now available. Samples of the new project are not yet available, but private tests are said to have demon- strated conclusively the superiority of this new product. Paper an Abrasive Previous attempts have been made to utilize paper as a lens wiper but were unsuccessful because of the inability to secure any paper substance which did not act as an abrasive. Camel hair brushes have heretofore been exclusively used for brushing a lens. Figure 1 Figure 2 30 INTERNATIONAL PROJECTIONIST December 1931 What does Television mean to You? M.M.. ERE is a new book that gives all the facts about this new and amazing offspring of radio. Avoiding technical terms it follows the development of television right up to date, explains principles, methods and apparatus, and weighs for you the problems, possibilities and probabilities of television as a commercial tool and a form of entertainment. Just Published TELEVISION by EDGAR H. FELIX Radio Consultant 276 pages, S^^xS, illustrated, $2.50 HAS television arrived at last? Can present broadcasting and receiving equipment be adapted to television? Will television of the future come by air or wire? This book from beginning to end was written expressly to supply reliable answers to these and hundreds of other questions you may have asked regarding television. With many explanatory illustrations and diagrams it gives a thorough background of technical facts — then makes plain their importance from the standpoint of the experimenter, the commercial operator, the broadcaster, the "listener-in." Order from INTERNATIONAL PROJECTIONIST 1 West 47th Street New York, N. Y. Covers television topics such as: —has Television really arrived ? — the HOW and WHY rif Television, ^—unsolved problems of Television, ^—possibilities of 100-line system, ^—latest synchronizin*!; method^. ^— the human 'eye in Television. ^— will future programs come by air or wire? ^— new developments affecting receiver design, •■^-future progress of Television. ^M 24 experts explain sound- recording and projection teRDlNCfi Sound |' FOR !'• Motion 1; Pictures |! TTERE is a book needed by every man connected with the *1 practical side of the talking picture industry, in theatre or studio. Written by the men who taught the screen to talk it covers every phase, both technical and practical, of sound '"Si!;.;^;'^; recording and reproduction. Recording Sound for Motion Pictures Published for the Academy of Motion Picture Arts and Sciences Edited by Lester Cowan 404 pages, 6x9, 229 illustrations, $5.00 Answers many questions on: — practical technique of recording — booms, blimps and microphones — recording systems — film laboratories — assembling the talking picture — reproducing systems — practice and problems of sound projection TWENTY-four sections, each written by a recognized authority and specialist in his field, present an authoritative description and ex- ' planation of the fundamental principles involved in recording and repro- ducing sound for motion pictures and their practical application in the studio, on location and in the theatre. Everything essential or important is covered, from the fundamental nature of sound, down to the practical aspects of volume control, theatre acoustics, and other everyday prob'.ems of sound projection. Order from INTERNATIONAL PROJECTIONIST 1 West'" 47th St. New York, N. Y Urreinhcr 1931 INTERNATIONAL PROJECTIONIST 31 S275 a pair WEBER SYNCROFILM SOUND EQUIPMENTS HAVE STOOD THE TEST IN AMERICA'S FINEST THEATRES not a bit EXPENSIVE yet such QUALITY! SYNCROFILM "B" SOUND HEAD For Simplex or Powers Compact and sturdy in construction, simple to operate, perfect in efficiency. Smooth, quiet, positive drive as- sures even tone quality without distortion. Sound heads are furnished complete and include optical systems, photo-cells, exciter lamps, adjustable motor mounting brackets, endless woven belts, grooved motor pulleys and all necessary attachments for projector. Money-Back Guarantee Easy to Install WEBER MACHINE CORP. 59 RUTTER STREET ROCHESTER, N. Y. Export Office: 15 Laight St., N. Y. C. A MODEL FORM OF PROPAGANDA FOR PROJECTIONIST UNIONS George A. Yager BUSINESS MANAGER, SALT LAKE CITY L. U. 250 TO begin any clear explanation of motion pictures it is well that you should understand that motion pictures are not really motion pictures at all, but a series of still photographs projected upon a suitable surface known as a mo- tion picture screen. These still photo- graphs, the approximate dimensions of which are % by % of an inch, are pro- jected onto the screen at the rate of 16 or more per second. The sensation of motion in these pictures is made possible by two f acts :. first, the rapidity with which they succeed each other upon the screen, and second, the persistency of vision. Persistency of vision is that quality of human sight through which the vision of an object is retained by the eye for an instant after the object is removed from sight. Due to this quality it is not only possible but a fact that 16 times every second the motion picture screen is in total darkness, that is, there is no pic- ture being projected upon it. This pe- riod of darkness is caused by the inter- ruption of the light rays from the pro- jector by what is known as a shutter and which resembles, in appearance, the wheels which are used on the parade wagons of a circus, in that they have alternate spaces of solid material and spaces which are punched out. Light Sources In the early day of the motion picture industry one of the greatest difficulties that had to be overcome was the perfect- ing of a suitable light source with which to illuminate the screen. An ordinary light would not do for the reason that the source itself has to be of very small di- mensions; and in the beginning of the present century the only known method of obtaining a light of any intensity was the electric arc which at that time was available only in a very crude form. The carbons which are used in an arc lamp to burn steadily and without flutter or flicker must be of uniform density throughout. Carbons themselves are made through a manufacturing process by which carbon, lamp-black and water glass, or silica, are combined. The lamp black and silica are used merely to hold the particles of carbon together. In some of our modern carbons there is a special inner core which is treated with various chemicals in order to improve the quality and quantity of light. Other forms of modern carbon are coated with copper in order to reduce their size and at the same time make them burn at the same rate as the larger uncoated carbon, which works with them. The reduction of size of the copper-coated carbon is for the purpose of increasing the amount of light from the other carbon by reducing the size of the shadow cast by the copper-coated one. Dr. Sapington of the National Safety Council advises me that lead has been discovered as an impurity in the copper- coating of carbons and that lead poison- ing is a possible vocational hazard of projectionists. In the early days of the industry 30 amperes current was about the maximum amount used on a carbon arc. However, with the passage of time 32 INTERNATIONAL PROJECTIONIST December 1931 and modernization of theatres the am- perage had to be increased along with the increased amount of auditorium light in theatres. Some of you may be able to remember the early motion picture the- atre which was in total darkness during the screening of a motion picture, except for the light which was reflected from the screen. Nowadays a modern motion picture theatre is so well lighted during the screening of a picture that it is possi- ble to read ordinary newspaper print during the screening. Early Equipment The early motion picture projector was a very crude and simple affair, having very few adjustments and a minimum of working parts. The entire roll of film was exposed all during the course of its screening, and in case of fire there were absolutely no safety devices to stop the spread of flames to the entire reel. No reel was provided for the film to be wound upon after it ran through the pro- jector. Instead, the film was permitted to run into an open sack at the base of the projector. This greatly increased the fire hazard, and it is quite common to find old time projectionists whose bodies are literally covered with the scars of burns received in the early days of the industry. In a great many cases the projection room itself was built of wood or other inflammable material, was of very sniall size, and located directly above the box- office of the theatre. Many times the pro- jection room or booth, as it was called in those days, had as the only means of entrance a trap-door in the floor, and in many instances the cashiers, to avoid be- ing bothered by the operators, who some- times needed a glass of cold-water, fast- ened the trap-door on the outside which imprisoned the operator in the booth; and in case of fire he was literally burned alive. There are still instances where operators are burned alive in operating rooms, a member of the Provo (Utah), local union having a fatal accident of this kind only four years ago. I will quote part of an affidavit from an usher in the theatre who was the first one to enter the operating room after the fire was over, to give you some idea of how a man looks who has been burned in a film fire: "I was the first one to reach the scene of the accident, being attracted to the projection room by an explosion. As I remember, the accident occurred about 8:00 p.m. I rushed to the projection room and found it full of smoke. When I got there the door was closed and I could hear shouts from within calling 'Help! Help! I can't see.' Graham managed somehow to open the door just as I reached for it. I rushed into the room and as I faced him I could see he was burned from head to foot. His clothing was burned from his body and he kept crying out that he couldn't see. I took my coat off and put it around him but he threw it off crying that he couldn't stand it. By this time he was burned beyond recognition. I finally succeeded in getting my coat around him and, with the help of an usher, took him downstairs to Dr. Arnold Robin- son's office which was adjoining the the- atre." Physical Hazards You will note that the usher speaks of the room being full of smoke. What he refers to as smoke was actually nitro- gen-oxide fumes. Again quoting Dr. Sapington, who says in part: Exposure to apparently trifling con- centrations (of nitrogen-oxide) may lead to profound edema of the respira- tory tract. The word "edema" refers to swelling in the lungs and the respira- tory passage because of the inhalation of nitrogen-oxide fumes. This swelling is so great and is so sudden in many instances that it causes internal suffoca- tion. Carbon Tetrachloride is used in fire extinguishers in projection rooms because of the fact that it is a non-con- ductor of electricity, but when carbon tetrachloride is played upon burning film is creates a very dangerous gas by combining with the nitrogen-oxide gases formed by the burning film. These fumes lead to inflammation of Hoffmann - Soons Every known quality necessary in producing perfect projection is embodied in perfection rheostats. PERF^JiON sV> SOLDERLESS ADJUSTABLE LUGS Heavily Constructed Will take wire sizes from No. 4 to No. 4/0 Recognized as the highest standard everywhere [ Sold by all branches of the National Theatre Supply Co., Sam Kaplan, New York; Continen- tal Theatre Accessories, and by your dealer. ] The Only Union-Made Rheostat We Build Rhec stats for Special Requi r e m e n t s . Communicate With Us Direct. There Is No Ob- ligation. R HOFFMANN - SOONS ELECTRICAL & ENGINEERING CORPORATION 387 FIRST AVE., NEW YORK HE OS TATS December 1931 INTERNATIONAL PROJECTIONIST 35 the respiratory tract, to pneumonia, to narcosis, and if the exposure is pro- longed, to degeneration of the liver, along with nephritis. Of course, you all know what pneumonia is. Narcosis refers to the condition of being over- come by exposure to the gases gen- erated when carbon tetrachloride is used as a fire extinguisher. The word "narcosis" is applied to any condition in which there is a loss of consciousness because of the toxic effects of various gases and liquids; we speak, for in- stance, of "chloroform or ether nar- cosis" for an example. Nephritis is Bright's Disease or a definite inflamma- tory process in the kidneys. Other very definite vocational diseases of com- moner occurrence but less direct in the production of physical impairment are: 1. Damage to the eyes from the in- tense glare of light reflected from the surface of the motion picture film, at times direct exposure to intense light. 2. Excessive temperatures. 3. Frequently, but not always, con- tinuous poor ventilation, even in the- atres in which ventillating systems are installed. 4. Lead-poisoning, which has al- ready been referred to. 5. Tuberculosis, caused by the in- halation of the fumes from burning carbons, which transmit free silica in large quantities to the projection room unless piped from the room by forced draft. I have a copy of an industrial award from the state of Wisconsin in which it is definitely shown that these conditions are occupational diseases of moving pic- ture machine operators. Safety Measures Motion picture film, as it is commonly called, is in reality nitro cellulose and is made from gun cotton. From gun cotton there is also made powder, dynamite, T.N.T., and other high-explosives. Yet film when burned in the open air will not explode, and should anyone tell you that it will, they are misinforming you. What causes an explosion when there is a film fire is the concentration of nitrogen-oxide gases which the film itself ignites when they have become dense enough. That is another reason why proper ven- tilation should be provided in all pro- jection rooms. You are all familiar with Kodak film and probably some of you have experimented with it and know how inflammable this material is; yet you were only dealing with a very small piece; whereas in the modern projection room a reel of film is a ribbon 1 inch wide and approximately 1,000 feet long. The picture program of a modern the- atre may run to as high as 12 or 16 reels which, as you will perceive, makes avail- able in the room to be eaten by flames from 12,000 to 16,000 feet of film. Should you ever be in a theatre when International Photographer Is a finely printed and beautifully illus- trated monthly magazine owned by the West Coast Cameramen's Union In all matters concerning the profes- sional motion picture photographers of the country it is the official organ It is designed to appeal to amateur followers of 16mm. cameras as well as to the most advanced technicians The columns of the magazine recog- nize the close relationship between the photographer and sound recorder If your news or kodak dealer does not carry the magazine on its coun- ters write for a sample copy to INTERNATIONAL PHOTOGRAPHER GEORGE BLAISDELL, Editor 1605 North Cahuenga Avenue, Hollywood, Calif. 25 cents a copy $3 the year a film fire breaks out, do not attempt to leave your seat until requested to do so by the management, and then proceed in a slow and orderly manner. A modern theatre is so constructed that there is no danger to the audience from a film fire itself; however, a great many people are injured in the stampede which goes along hand in hand with the panic occasioned by some foolish person in the audience yelling "Fire!" Prior to the introduction of sound pic- tures there was only one motion picture operator on duty in the operating room at a time; but with the introduction of sound pictures two men were placed in projection rooms. There are numerous duties around a projection room which take a man from the side of his projector, if he is alone in the room. That is the reason why the members of our Union insist that two men be on shift at all times, so that not only the operator him- self is properly protected from the fire, but the entire audience as well. The fire hazard has increased since the introduction of sound for several reasons. Among these are a more intense and therefore hotter light concentrated upon the film so that a picture of the same bril- liancy could be obtained on a screen which is about 30 per cent transparent 34 INTERNATIONAL PROJECTIONIST December 1931 25'"ANNUAL SEAL YOUTH and STRENGTH Help fight tuberculosis Buy CHRISTMAS SEALS THE NATIONAL, STATE AND LOCAL TUBERCULOSIS ASSOCIATIONS OF THE UNITED STATES as was formerly obtained upon an opaque surfaced screen; also there is more wear on the film by the introduction of two more sprockets in the sound mechanism of the projector, and increased projec- tion speed in some cases which adds to the wear of the sprocket holes on the film. Sound Pictures Motion pictures with sound are made possible by the combining of discoveries, some of which are older than moving pictures themselves. For instance, trans- formers or repeating coils, as they are called by telephone men, are much older than motion pictures. You have seen transformers, those big black boxes which hang at the top of power poles and which are used to change electric current from one pressure to another, or one voltage to another. Other things which have made sound pictures possible are photo-electric cells, or electric eyes as they are sometimes called, which very much resemble an ordinary radio tube and which work much the same as a tap in a water pipe, except that they are turned on and off by light rays and when they are turned on they permit an electric current to flow- in a circuit instead of water flowing through a pipe. The mechanical features of sound picture apparatus involved noth- ing that was not already known to every- one in the industry. They simply needed to be adapted to their new uses. A modern sound picture installation looks very much like the panel board in a broadcasting station. There are two methods used for recording sound pic- tures; the sound-on-disc method and the sound-on-film method. Sound-on-disc. from a mechanical standpoint, is not however, faithful reproduction of sound is possible over a wider range of sound frequencies with discs than with sound- on-film. Labor Organizations In the early days of the industry the motion picture projectionist had not yet been organized into labor unions, and as a consequence he labored long hours in projection rooms, which at that time were called booths, and under conditions which were deplorable. The pay was low. There were no facilities for sanitation or ven- tilation. As the industry grew and a better type of man was attracted to our profession they were organized into the Interna- tional Alliance of Theatrical Stage Em- ployees and Moving Picture Machine Operators of the United States and Can- ada. Prior to this time the stage em- ployees were the only craft represented by this international union. Today all branches of the industry are served by members of the international union and we now have, in addition to the stage em- ployees and moving picture operators, studio mechanics, motion picture camera- men, still photographers, laboratory workers and sound technicians. So, all technical departments in both the produc- ing and reproducing sections of the in- dustry are served by members of our RCA Portable Reproducer This unit comprises a projection ma- chine, an amplifier, a loudspeaker and a carry-case for film and these have an aggregate weight of slightly more than 200 pounds. The projection machine is 19" high, 19" wide and its breadth is 10". The amplifier, which is built in a carry-case having a removable cover, is 26" long, 8%" high and 11" in breadth. The loudspeaker, which is of the flat baffle type, is contained in a carry-case, the dimensions of which are 8V2 x 19 X 14". Standard 35 mm. film is used and ade- quate sound reproduction is obtainable in a room or hall having a content of 75,000 cubic feet when using the 8-inch directional baffle. A 6-inch dynamic cone speaker is supplied when the cubic content does not exceed 12,000 feet. A picture about 8 x 10 feet in dimensions is obtained upon the screen from a throw of 75 feet. The equipment is AC-oper- ated from an outlet of 105 to 125 volts, either 50- or 60 cycle, single-phase power source. THE BOOK OF THE MONTH THE BOOK OF THE YEAR THE BOOK of the MOTION PICTURE INDUSTRY Manual ^AHERON SOUND PICTURES AND TROUBLE SHOOTERS MANUAL By JAMES R. CAMERON and JOHN F. RIDER Introduction by WILLIAM F. CANAVAN (Inter. Pres. I.A.T.S.E. & M.P.M.O.) LATEST MOST COMPREHENSIVE AUTHENTIC BOOK ON THE SUBJECT PUBLISHED J930 USED BY THE MOTION PICTURE INDUSTRY THROUGHOUT THE WORLD AS THE STANDARD AUTHORITY USE THE COUPON A COMPLETE GUIDE for TROUBLE SHOOTING U. S. DEPT. OF COMMERCE THE LEAGUE OF NATIONS (MOtToN picture SECTION) (CINEMATOGRAPH INSTITUTE) ^, . . ,^ . \ L ij L • tU "Mr. Cameron is one of the very limited These books (Cameron s) should be in the „„„ber of technical writers on cinematography possession of every projectionist, theater man- really worth reading." ager and everyone interested in receiving au- "His books are of particular interest be- thentic information regarding the application cause, although essentially technical and based r. > u 1 upon theoretic principles, they are nevertheless of sound to motion pictures, t^ameron s booKs -.i • .i_ e j • l* » ui suuiiu lu iiiuiiun tF.».iu.ci. ^ within the grasp of any reader wishing to ac- are a worth while contribution to the motion quire a knowledge of the sound-film in all its picture industry. aspects." ENDORSED BY THE TRADE PRESS THROUGHOUT THE WORLD 7p^. The making and showing of Sound Motion Pictures, Sound- ^tK ^l) ■jll On-Film and Sound-On-Disc is covered thoroughly and in an J ^^^^^ ^^^^^ expert manner. The book is written so that the subject mat- M - /v/v ter is easily understood. Explains in detail the construction, m 1 l||| 1 llll operation and care of sound recording and reproducing equip- B "^ ment. Every known trouble to sound equipment is listed in this book 'with full simple directions for its cure and explana- tion as to its cause. A Complete List of Our Motion Picture Books Sent on Request. YOU WANT THE BEST— THEN ORDER A CAMERON BOOK CAMERON PUBLISHING CO., WOODMONT, C 3NN., U. S. A. GENTLEMEN: HERE IS MY SEVEN-FIFTY. SEND ME A COPY OF SOUND PICTURES. NAME ADDRESS Insist on . . d n d Solve Your Cell Problems PHOTOELECTRIC CELLS Projectionis+$ and managers alike, insist on Visitron Photoelectric Cells, once they've tried them in their equipment. The Brilliant Sound Performance of Visitrons cannot escape the attention, nor fail to gain the instant approval of men who are particular about the quality of their Sound Reproduction. A Comparative Test will prove to you their superiority — emphatically . . . Guaranteed Long Life; con- stancy; crystal tone clarity; abolishment of trouble and worry — Perfect Performance. Try a Visitron, today. Hear the difference! Manufactured by G-M LABORATORIES. 1737 Bolnnon+ Avenue, Chicago, III., U. S. A. NO Order them BY NAME from NATIONAL THEATRE SUPPLY COMPANY i fn/eff)0//ono/ OJECTIONISl £c//tecf by James J. Hnn Issue: TESTING CIRCUITS A. C. Schroeder continues his series of articles on the proper methods of testing electric cir- cuits. Practical data prsented in practical fashion by a practical projectionist. LAMP EQUIPMENT Pertinent comment on correct lamp equip- ment and approved methods of operating tech- nique by R. H. McCullough, Fox West Coast projection director. EMERGENCY HOOK-UP A novel means employed by M. D'. O'Brien, Assistant Director of Projection, Loew Thea- tres, to keep the show going. POWER SUPPLY A timely and provocative analysis of D. C. power sources by Samuel Bagno. Rebuttal comment by experienced workers in the field. — and Other Articles D. C. NEWS and VIEWS DIAGRAMS TECHNICAL HINTS NEW EQUIPMENT No. 'ebruary, 1932' A magazine devoted to better visual and sound 25c. a CO $2.00 a yc TWO NOTEWORTHY ACHIEVEMENTS IN PROJECTION EQUIPMENT Complete rear shut- ter attachments show- ing framing device, shutter adjusting de- vice, framing light, hinged eye shield, cooling plate, fire shutter lever and gate opening device. New Low Price: $85 B. & S. Rear Shutter reduces aperture heat by 70%, minimizes effect of warped and buckled film, and keeps film free from dust and dirt. Exclusive blade feature of this shutter keeps hot air from film and insures constant supply of cool air arotind the aperture. The results of a test by the Massachusetts Department of Public Safety in a Boston theatre on Janu- ary 19, 1930, are as follows: Without B. & S. Rear Shutter Aperture Heat: 1250° F. With B, & S, Rear Shutter Aperture Heat: 340° to 350° F. Installation can be made in one hour on any single- or double-bearing projector mechan- ism, without any cutting or drilling. Periodic oiling is the only maintenance requirement. Rear shutter equipment includes cooling plate, framing device, shutter timing adjust- ment, and a framing light. A hinged eye shield permits easy accessibility to the me- chanism. B. & S. Change-over consists of two shutter blades contained in a housing de- signed for attachment to the cone of the lamphouse and operates on either A.C. or D.G., at 110 to 125 volts. Novel design eliminates any possibility of double exposure on the screen, and makes the change invisible to the audience. B. & S. Change-overs operate efficiently on either A.C. or D.G., but coils for the proper current will be supplied on specification. Coils of the B. & S. Change-over will stand up under heavy overloads and w^ill not burn out. The constant arcing in an ordinary change-over switch soon causes the metal contacts to burn and corrode. All B. & S. switch contacts are made of carbon that cannot corrode. B. & S. unique design also prevents the flash from touching any part of the switch. This switch cannot stick or bind and is positive in operation. B. & S. Change- overs have been used for many years in Publix, R-K-O, and other major theatre circuits. Write for particulars to BASSON & STERN For fifteen years manufacturers of high grade motion picture equipment 749 EAST 32nd STREET, BROOKLYN, N. Y. February 1932 INTERNATIONAL PROJECTIONIST PRL SOUXD SYSTEM TYPE 9-AG A Complete All A. C. Operated Theatre Amplifier For Sound-on-Film Reproduction THE type 9-AC Sound System is designed to meet the require- which supplies the current to the exciter lamps without the aid ments of all theatres having a capacity up to 1,200 seats. of filtering. This unit, as illustrated above, is a complete and slelf -contained For convenience and simplicity of operation the controls are power supply and high-gain amplifier designed especially for placed in the top and front of the cabinet. These include a sound-on-fi.m reproduction and constitutes the entire electrical volume-control and sound change-over switch. The amplifier apparatus necessary between the P. E. cells and the stage horns. and. all apparatus is mounted on a steel panel as shown at the right above. This feature makes it possible to remove the entire Being comparatively small, this unit is placed between the assembly from the cabinet without disturbing the conduit con- two projection machines, connections to the P. E. cells, exciter nections from the cabinet to the sound heads and other appara- lamps, horns and A. C. line being brought in to a marked ter- tus. This permits quick inspection and facilitates servicing, minal strip through knockouts provided in the sides and bottom The unit, as a whole, is substantially built and presents a of the cabinet. In addition to supplying the current for the very pleasing appearance. Only the finest materials obtainable P. E. cells, this unit is equipped with a new type transformer are used and all parts are standard and interchangeable. Specifications : VOLTAGE GAIN 90 DB NUMBER OF STAGES 4 TUBES REQUIRED 1-224, 2-227s, 2-250s, 2-281s POWER OUTPUT '. 15 watts INPUT IMPEDANCE Caesium photocells OUTPUT IMPEDANCE Three 15-ohm lines P. E. CELL CURRENT 90 volts EXCITER CURRENT Up to 10 volts at 8 amperes FADING SYSTEM Exciter change-over POWER SUPPLY REQUIRED 110 volts, A. C, 50-60 cycles POWER CONSUMPTION 300 watts SIZE OF CABINET 20 in. x 16 in. x 9 in. NET WEIGHT 55 lbs. SPECIAL VOLTAGES TO ORDER For further information, write or wire our nearest distributor, or PACIFIC RESEARCH LARORATORIES 1907 Fourth Avenue Los Angeles, Calif. ^iiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii^^ INTERNATIONAL PROJECTIONIST February 1932 For better quality picture and sound re production Lightweight — yet sturdy, rigid and durable The Projection Reel Designed by a Projectionist for Projectionists 1\ O seams, no brazing and no welding to break open or come apart when rewinding or while in the projector. Made of a special aluminum alloy which results in a lightweight yet sturdy and rigid reel. No rough edges to cut the fingers or damage the film. The True Reel for Projection Sold by All Leading Dealers PRICES: 15 in. reel with 5 in. hub $3.00 each 11 in. reel with 5 in. hub $2.50 each Manufactured by W. & W. Specialty Co. 159 West 21st St. New York, N. Y. February 1932 INTERNATIONAL PROJECTIONIST ROJECTIONISl Edited by James J- Finn Volume I FEBRUARY 1932 Number 4 Monthly Chat 5 Fundamentals of Testing Elec- tric Circuits 7 A. C. SCHROEDER An Improved Method of Remov- ing Intermittent 9 J. M. RUGINO Light and Lenses 10 Victor A. Welman Operating Hints 12 Comparative Worth of D. C. Power Sources 13 Samuel Bacno Wanted: A National Society of Projectionists 16 James J. Finn Damaged Film: Deficient Equip- ment and the Responsibility Therefor 17 Lamp Equipment: Operation and Maintenance 19 R. H. McCULLOUGH Duovac Tube Characteristics 20 21 Emergency M.G. Hook-Up M. D. O'Brien News and Views 22 Overloading of Carbons 19 S.M.P.E. Okays .590 x .825 Pro- jection Aperture 22 Cleaning Sound Screens 23 The Patent Page 24 Proper Shielding for Electric Cir- cuits 25 John A. Ferguson Philosophic Background of Unions 26 Sumner H. Slighter Notes from the Supply Field 29 S.M.P.E. Projection Committee Work Invaluable — Goldsmith 29 Studio Agreement Concluded Miscellaneous Items News Notes Technical Hints 31 Published Monthly by JAMES J. FINN PUBLISHING CORP 1 WEST 47th STREET, NEW YORK, N. Y. West Coast Representative Hallett E. Cole, 846 South Broadway, Los Angeles, Ca lif. ('Phone: Tucker 6428) Yearly Subscription: United States and possessions, $2 (two years, $3) ; foreign countries, S2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Entire contents copyright, 1931, by y ame8 J. Finn Publishing Corp. International Projectionist is not r<;sponsible for personal opinions appearing in signed articles in its columns. Cover design by Morgan Bryan. MONTHLY CHAT MOST important among recent devel- opments in this field is, as we see it, the substantiation of our time-worn argument that in any proposed change of standards the theatre should receive first consideration. The activity incident to the introduction of a new aperture standard leaves no room for contrary opinion on this topic. The proposed new standard was ballyhooed by studio technicians as representing truly "artistic proportions." With this statement we are in accord. When it came time to estabhsh these "artistic proportions" upon the screens of theatres, however, the sponsors found that there is a very great difference be- tween the artistic ideal and the technical necessities of picture presentation — not to mention certain economic considerations which, we admit, have no rightful place in the sphere of "art." To make a long story short, it has been conclusively demonstrated that produc- tion must take second place to exhibition, and, further, that the only worth while motion picture god is the fellow who walks up to the box office and lays down the price of admission — for which, don't you think? he must be given full value in good pictures properly presented. JUST when we thought we had bested our major problems, along comes a new headache. Projectionists who are now afflicted with those very efficious theatre managers who insist that carbon consumption is much too high, will soon have to deal with this trouble in aggra- vated form. Fcr (it breaks our heart to have to tell it), a p'.an is afoot to attempt through the medium of a magazine to educate the heretofore uneducationable manager in projection matters. Which means that very soon the manager will b^ able not only to intimate that carbon con- sumption is too high but to go right into the projection room and demonstrate. Pocket size, of course, so that the man- ager can stick it into his tuxedo coat pocket. Full details later. Projectionists will appreciate this further aid in their work. THE big news within the next month will be Western Electric's announce- ment of a greatly improved recording and reproducing process. The frequency range is to be "extended" and merely good sound reproduction will not be ac- ceptable in the future. Of course we've scooped all our colleagues on this little announcement, but since our scouts have picked up only the outlines of the process we shall have to be content and await the formal W. E. announcement next months INTERNATIONAL PKOJECTIONIST February 1932 AMPLION OCTOPHASE SPEAKERS AUDIBILITY - INTELLIGIBILITY - DURABILITY EFFICIENCY and FREQUENCY RANGE Choose the AMPLION OCTOPHASE // is so much finer, yet costs so little more \ AMPLION OCTOPHASE GIANT DYNAMIC AIR COLUMN UNIT Weight IS lbs. Height 5% in. Diameter 5% in. Field Coil Resistance 5 ohms. Field Coil Supply 6 volts D. C. Field Current Consumption 1.2 amperes. Voice Coil impedance 16 ohms. Maximum Capacity 23 watts. Permanent Capacity 6 watts. Shipping Weight 21 lbs. Shipping Dimensions 12x12x12 in. This unit is also supplied with 1500 ohm field coil. Field Supply 110 volts D. C. Field Current Con- sumption 75 milliamperes. CONSTRUCTION In this unit, the area over a scientifically domed dia- phragm encased in a scienti- fically shaped air chamber is divided into eight divisions. The centers of gravity of each of these divisions are exactly equi-distant from the throat of the unit, and since all operate under identical pressures, the sound impulses from each di- vision reach the throat of the horn in perfectly timed syn- chronism with the arrival of sound impulses from all other divisions. From these eight divisions this reproducer de- rives its name — OCTOPHASE. AMPLION NINE-FOOT THEATRE HORN JW-9 The JW-9 Horn is especially designed for theatre and indoor use. No horn of such great clarity and wide frequency range has ever been concentrated into so small a space. It covers the full speech range perfectly pre- venting over resonance and muffling on base notes. As a reproducer rAMViHit'j ■■ "^ **'" *""®'<^' •' possesses a Bmiufl lii M. brilliancy impossible of attainment in horns made of soft materials. Its nine foot air column and wide bell, assure excellent performance on (he low notes. List Price $95.00 Air Column 108" Bell 34" X 26" Bell Area 720 sq. inches Weight 33 lbs. Shipping Wgt. 70 lbs. Shipping Dimensions 38"x33%"x39" Angle of Spread measureif at lip of bell 36° Heiglil 42" Width 34" Depth 37" It is those overtones from 5,000 to 8,000 cycles which give character to speech. Can you afford to nullify your entire equipment by employing speakers which cannot reproduce these frequencies? Write for folder describing the OCTOPHASE unit and complete line of AMFLION exponential weatherproof horns AMPLION PRODUCTS CORP. 38 West 21st St. New York, N. Y. FEB IP 1932 ©ci B 144330 INTERNATIONAL PROJECTIONIST / VOLUME I NUMBER 4 FEBRUARY 1932 FUNDAMENTALS OF TESTING ELECTRIC CIRCUITS A C. Schroeder MEMBER, I. A. LOCAL UNION 150, LOS ANGELES, CALIF. II IN figure I is shown a simple two-wire circuit. It is surprising how many things can happen in such a circuit and the different methods that can be used in testing it. The use to which this circuit is put often has a large bearing on the test and in interpreting the results of it. Assume that the drawing represents a line carrying 110 volts and that the end at A is connected to the source of sup- ply. The wires at B go to the device that constitutes the load, but for the present we will assume that it has been discon- nected by opening a switch. Near the v end B are two fuses. ■"*•* ' '4 Both wires should be continuous from A to B, that is, if nothing is wrong. For the first test we place the leads from a test lamp across the terminals of the fuse block at the end nearest B. If the lamp lights, it is an indication that current is flowing through the lamp and that it probably is coming from A. This might sound like a queer statement, but the fact that the lamp lights when connected to the end of the line at B is not positive proof that the line is continuous. The line could be broken, as at X in Figure 2, and if there is a circuit of some kind around the break, as shown by the dotted line, the lamp will light. It is true that such a condition is not very apt to occur in a line such as we have under discussion. It is, however, not at all un- likely to happen in an amplifier or its associated apparatus, with the usual re- sult of noisy operation or possibly one or more tubes working at a wrong volt- age, etc. The condition that is not likely to happen is tlie one that stumps the man who does not take all the possi- bilities into consideration. As a rule it can be taken for granted that the current is coming from A when the test lamp lights. If any doubt exists (and it must be established if this is so), simply opening both sides of the circuit at A will establish the fact. If this causes the lamp to go out, it shows that A is the source of power; if the lamp remains lighted, the current must be com- ing from some other place. Figure 3 shows how such a condition might occur. We have a line from A to B as before, but it is broken at X-X and two wires are brought down to C where they are con- nected to a different power supply. Suppose that the lamp does not light. The next step will be to see that the test circuit is O.K. Place the test lamp across a circuit that is known to be in good condition. This can be done by testing across the fuses that connect to the projection room lights, the amplifier circuit, or somewhere in the circuit be- tween the motor generator set and the projection arc. If the projection room lights work, if the amplifier is lighted, or if the arc is lighted, we know that these circuits are O.K. Should the test lamp light when put across any of these, it shows that our test circuit was in good shape and that the current was not get- ting to point B in the line we have under discussion. If it is shown that the test circuit is at fault, we try another lamp, one that has been working somewhere, or we can take the lamp out of the test circuit and try it in a socket in which a light has been burning. If the lamp was in good condi- tion, the trouble is either a broken wire, or the lamp was not screwed down in the socket. Now that the test circuit is O.K., we again test at B. Suppose that we still do not get any indication of current. The test terminals are then placed across the ■nr E Figure 1 B X Figure 2 B [7] INTERNATIONAL PROJECTIONIST February 1932 X X B Figure 3 other end of the fuse block, the end farthest from B, and we find that the lamp lights here, which shows that the trouble is either in the fuses or in some part of the fuse block. One wire from the test lamp is then touched to C (Fig. 1 ) , and the other wire to D. If the lamp does not light, it shows that the lower fuse is probably blown. Ninety-nine times out of one hundred it will be the fuse; but we must bear in mind that it is possible for the trouble to be in the fuse receptacle. If the lamp lights when this test is made, it shows that the lower fuse and the clips into which it fits are O.K., at least there is no open circuit, so the leads are touched to E and F. The results of this test are interpreted the same as the test from C to D. Sometimes it is easier to locate the trouble by testing while the load is con- nected. Assume that the load connected to B in Figure 1 draws 100 amps, when everything is normal. At this particular time the apparatus will not function, so the switch is opened and the test lamp is placed across the end of the fuses at B, and the lamp lights, showing the fuses to be O.K. Since there are no other fuses between this point and the load, it is evident that something has gone wrong in some part of the apparatus or the wiring. It is convenient to start at the fuse block, so we close the switch, throwing the load back onto the line. Another test is made across the fuses at the end B and we find that the lamp does not light. Let us analyze this condition to see just what happens. Our test lamp lights when the load is not connected ; but when the load is thrown on, the lamp goes out. A test is now made across the fuses on the side nearest A and the lamp lights even with the load connected. When the load is hooked onto the circuit, the volt- age across the B end of the fuses drops so low that the lamp will not light, which means that the voltage probably drops to about 20, possibly less than that. We found the voltage across the other end of the fuses still was 110, so the trouble must be somewhere in the fuses or in the fuse block. Subtracting 20, the volt- age at B, from 110, the voltage at the other end of the fuses, gives 90, the volt- age-drop in the fuse block. Under these conditions there are about 1.800 watts of energy consumed due to the resistance somewhere in the fuse block. This is approximately three times as much as an electric flatiron uses, so it stands to reason that a great deal of heat will be produced. This will be discov- ered very quickly — in fact, if the circuit is left in such a condition, the fuses will blow due to the heat. The point is that heat is generated and can be found quickly by touching the parts — carefully, of course, as they may be very hot. It should be kept in mind that cartridge fuses having round ends that fit into the clips often run quite warm when 50 to 60 amps, are taken from the line. That is why fuses of larger capacity are made with the knife-type contacts. Since we are discussing principles, and also because we cannot locate the exact point of the trouble by looking for the heated parts, we continue with the test- ing. Ninety volts is enough to light the test lamp quite well, so we test from C to F, in Figure 1. Nothing happens. This side of the circuit is probably O.K. Then the test is made from E to D and the lamp lights, not to full brilliance, but still quite brightly. Evidently this must be where the trouble is, because normally there should be no drop in voltage across these two points. The test leads can now be placed on the ends of the fuse, as in Figure 4. The lamp probably will not light, since it is unlikely that a high resistance will de- velop in the fuse. S'uch a condition would cause the fuse to burn-out almost immediately. Testing as shown in Figure 5, from the terminal screw to the end of the fuse. quickly shows on which end the trouble is, since the lamp is now across all the parts at this end of the block. If the lamp does not light at one end, the test is repeated at the other as a check, and if it lights, we proceed to dig deeper. Test from the clip to the fuse (Fig. 5). If the lamp lights, we have found the trouble — a poor contact between the fuse and the clip. Continuing, one lead is placed on the part to which the wire is fastened and the other lead on the bare wire, as in Figure 7. High resistance caused by a loose wire or corroded wire is found by this test. Figure 8 shows the remaining point to be tested. It will show if high re- sistance is present between the clip and the part next to it, the part with the screw in it under which the wire is fast- ened. By this time it should be apparent that the idea is to get the test lamp across the part of the circuit in which the high re- sistance exists. The exact location can be found in this manner. Of course, it is not logical to start the search by testing every small part of the circuit, step by step. In a large and complicated circuit such a procedure would take a long time. A large portion of the wiring, etc., is eliminated in the first few tests. Let us go through some of the steps again, with- out going into details. The test lamp across B in Figure 1 showed a presence of voltage. Next, the load was thrown on and there was no voltage at this point, that is, not enough to light the lamp. Testing across A showed that the full line voltage was present. We have made three tests and have eliminated every- thing on the line side of the fuses and probably have eliminated everything from the fuses to the device we wish to operate. One more test showed that the upper February 1932 INTERNATIONAL PROJECTIONIST fuse and the clips were not the seat of the trouble. We proceed to the lower fuse and it is evident that the trouble is right around this portion of the equipment. It is possible that the exact point where the trouble is has not been found after all the tests have been made as set forth. In such a case we must test across each piece of metal that was in the circuit when we made the test shown in Fig- ure 5. It sometimes happens that cracks and seams occur in manufactured articles. Suppose that one of the parts is cracked, possibly on the under side where it can- not be seen. One test lead is put on one end of the part, and the other lead on the opposite end. The lamp lights if the part is defective. It is seldom that all the tests would have to be made as outlined in this arti- cle. The trouble will usually be found after a few tests are made. If the reader has gone over this carefully, he will have no trouble in applying the ideas con- tained here to other apparatus, such as switches, terminals on motors and trans- formers, low resistance windings, etc. As we go along we will take up other meth-' ods of making similar tests, and then tests on circuits of higher resistance and hav- ing other kinds of trouble. AN IMPROVED METHOD OF REMOVING INTERMITTENT IN the days before sound pictures the changing of an intermittent mechan- ism on Simplex projectors offered no serious difficulty, and the job could be done quickly. Referring to the accom- panying illustration, the procedure was as follows: On the gear side of the projector, first remove screw S-209-G and then the main drive gear G-112-G. Then, on the thread- ing side of the projector, remove collar C-192-G. Then, returning to the gear side of the projector, grasp the flywheel of the intermittent with one hand and the G-12 with the other, and pull both easily toward you. The intermittent thus came out (with the G-12). This process was reversed in replacing the spare intermittent, and the shutter was, of course, re-timed. The. attachment of sound reproducing equipment (in this case we refer to W.E. ) , meant the addition of a yoke and some extra gears to the projector which make it difficult for the projectionist to remove the intermittent quickly in an emergency, because he would first have to remove the yoke and the extra gears which are in his way. To follow the in- structions mentioned above for this job would add from 15 to 30 minutes to the job. At present the better procedure is not to remove G-112-G but to proceed as fol- lows: On the gear side of the projector re- move screw S-145-G and washer W-140- G; then push shaft S-446-G through the gears G-1346 and G-12, being careful to hold these gears so that they do not drop sharply as they are disengaged from the shaft. The intermittent is then pulled carefully toward you and is out. It is understood that prior to these operations the film trap is removed and the cover clamp C-294-BB has been turned away. The process is reversed v/hen replacing a mechanism. Care should be taken to insure that the letter "0" on G-12 and on the intermittent fly- wheel are parallel. Thus shutter is, of course, re-timed. — J. M. Rugino. ALEOGRAPH VS. W. E. The Aleograph Company has lost its appeal in its suit against Electrical Re- search Products, Inc., in which infringe- ment was claimed against the Western Electric Sound System, according to in- formation received recently from New Orleans. The patent in question. No. 1,494,514, is entitled "Art of Producing Motion Pictures and Sound Synchronized Therewith." LIGHT AND LENSES Victor A. Welman A lecture given by Victor A. Welman be- for Cleveland Chapter No. 18, American Projection Society, on November 18, 1931, forms the basis for this article. — Editor. THIS will be a talk on lenses, leav- ing to some future time a discus- sion of the modern theory of light and its propagation. The theory of light changes almost from month to month and it requires constant reading to keep up with the procession. It is safe to say that no ordinary reader can keep up with these developments. "' : ^' ' The laws goverriiffg lens action, how- ever, are well established and have been for many- years. The principles to be outlined here can be found in a book' published in 1897 and which I studied in 1900 — 31 years ago. These dates should not surprise anyone, because the fundamental law governing the action of various shaped lenses were promulgated by Huygens about 1670, from which we can understand that it is not by any man- ner of means a recent development. I cite the antiquity of this principle only to emphasize how unnecessary has been the widespread misunderstanding of lens action in the minds of many of those working with them, particularly among members of our own profession and, unfortunately, in most of the books published for popular study. Misinformation Figure 1 is a classic illustration to be found in almost all our books as illustrat- ing the course of light waves in pro- jection optics. This drawing is the source of most of the misunderstanding current on lenses. It is what can be properly termed a shorthand drawing — telling the true story if one knows how to read it. In its original location in a textbook, following the explanation of the Huygens construction, it is clear enough; but when lifted into the popu- lar books without proper explanation it does not tell a true story. Now let's get into the subject. We'll try not to be logical — which means that we shall try to make it interesting. It has been my experience that a logical presentation of a subject dried it out. What is light? I answer, "I don't know." Dr. Miller doesn't know. Dr. Michaelson didn't know. Even Einstein doesnt' know. So, why should we worry about it? For purposes of discussing light in lenses it is customary to consider light as a wave-motion in the ether ; but do not forget that there is no ether and that some scientists say that it is not wave- motion — so there we are chasing our tails again. To get started, let us say that a ray of light is a train of impulses pro- jected through space by an excited elec- tron. This train of impulses obeys cer- tain laws — and it is a couple of these laws in .which we are interested. How big is a ray of light? Light Rays We get into the habit of thinking ot a ray of light as we do of a pencil line on paper, and we know, of course, that i ray of light is commonly expressed in this fashion. But it is not a ray but multiple rays — a,; million, perhaps. An electron is about a hundred-millionths of a millionth-of-an-inch in diameter. If. one of these electrons is vibrating at sucji an amplitude that the resultant wave can be seen as light, hundreds of these waves could ride in a tube the size of a human hair and still leave ample elbow room. So, a line on a piece of paper represents not one ray but millions of rays of many frequencies which can be separated into their various frequencies just as a filter can separate radio waves of various frequencies. Huygens suggested in 1670 that light waves emitted from a point source of light advanced in all direction, and that if a surface is drawn through all the points of vibrations in the same phase, this surface will be a wave-front and the direction this front is advancing is a ray ' "Theory of Physics" by Ames. No.5 (what's this? ... a ray of light is a direction only and hasn't any size at all. That's even smaller than I said it was ) . Now, Huygens says further that every point in that wave-front acts as a propa- gator of wave energy and starts a new wave-front, so that if we deal with wave- fronts and not with rays, which are di- rections only, we can predict just what will happen when light passes through lenses. Now our drawing (Fig. 1), starts to take on meaning. It never did, in the original, intend to show the course ot light rays but an envelope containing some wave-fronts. Figure 2 illustrates the principle. Take a wave-front at AB. Each point on that front propagates a new front, and if we draw a line through similar points on each of these smaller wave- fronts, we get a new wave-front A'B'. Now, when a wave-front goes through a hole we know from experience that it does not cut-off sharply around the edges but the small wave-fronts lap around the edges, although the main front passes on in its original direction. ' Wave Direction If these wave-fronts are getting larger, they are called diverging waves. If they are getting smaller, they are called con- verging waves. If they are progressing in a plane, they are called plane waves. Now, light travels in the air at one velocity, but slows down when traveling through glass. In light coming from the sun the wave-front has a radius of 90,000,000 miles. A small arc of a circle of that diameter would be, as far as we on earth are concerned, a straight line aiid those waves come to us as plane waves. Consider in this drawing (Fig. 4), a plane wave-front approaching a bi-con- vex lens. This wave-front hits the glass in the middle ,of the lens and that part of the wave slows down; as each part of the front hits the glass it slows down. Then the upper end of the wave-front gets out into the air and speeds up again. That part still in the glass holds back until it is all out, and the front is now converging and comes to a point which is called the principal focus of the lens. With a concave lens, the ends of the wave-front are slowed up first as they hit the glass, the belly speeds up first when it gets through the glass ahead of the ends, and a diverging wave emerges [10] February 1932 INTERNATIONAL PROJECTIONIST 11 (Fig. 5). Suppose the one face of this lens were flat: it can be seen in the drawing that a diverging wave still would come out of the lens but it would not be diverging so rapidly. By the way, where is the focal point of this lens? We described the focal point of the other lens as the point where plane waves were brought to a point, but here these plane waves do not come to a point. This is a negative lens, and the focus is on the opposite side of the lens from which the rays emerge and is called a virtual focus, as distinguished from the real focus of the other lens. I said that wave-fronts from the sun may be considered as plane waves. For all practical purposes a light wave-front originating, say, 100 feet distant may be considered as a plane wave-front. The waves from your screen to the projection lens are diverging waves, and from the lens to the screen are converging waves; but for practical purposes they may be considered as plane waves. You prob- ably won't believe this, but we'll prove it sometime. Taking leave of plane waves for a while, let us consider diverging waves. You will note that the action in Fig. 6 is exactly the same. The belly flattens out, the front straightens out; then the ends get out first and the front begins to con- verge, but comes to a point much further out. These two points are called the conjugate focii of the lens: "jugate"' means joined; "con" means together; the "conjugate focii" are the two points joined together or related in this particu- lar lens, and a point light source placed at either place would be focused at the other. (Note that I said point source.) If we move this point source closer to the lens (Fig. 7), the emerging front is curved less and less until when the light is at the real focus of the lens, the emerging wave-front is plane. Aberration When we move the point source in further to a point within the principal focus of the lens (Fig. 8), the wave- front does not get a chance to straighten out, the ends never do catch up, and it emerges as a diverging wave. This is all very simple — much too simple, in fact, for in practice nature hands out a lot No. 13 of jokes and jolts to such things as preconceived notions and the like. We will spend a few minutes considering some of these "jokers." First we shall consider spherical aber- ration (Fig. 9). The very thing that makes a lens change a wave-front (the varying thickness of glass), also causes the rays at different distances from the center of the lens to focus at different points — with the outer rays focusing closer, and the inner rays focusing far- ther away from the lens. This condition is corrected by various methods of grind- ing and by combinations of lenses. We have an example of partial cor- rection in Cinephor condensers, wherein one surface is parabolic and the other spherical. One point frequently over- looked is that even in the very best photographic lenses spherical aberration cannot be wholly corrected. The outer rays may be made to meet the inner rays, but the intermediate rays will not meet at the same point. The larger the dia- ^(({i+^*'+}j Ho,7 meter of the lens, of course, the greater the difficulty of correction. Hence, in a camera the smaller the diaphragm, the sharper the picture; in a projector, a diaphragm will sometimes improve an inferior projection lens, although cutting down the light. Another difficulty is chromatic aberra- tion (Fig. 10). We said at the beginning that a pencil of light (represented by a line), was made up of millions of rays of light. If the light be white, it is made up of rays of many different wave-lengths — thousands of them, perhaps. Now, the effect of glass upon the speed of these rays is far different for each individual wave-length, so that if you had a lens corrected for spherical aberration, all the rays still would not come to a point: the blue would focus at, say, b and the red at r, and all the others in between. Fortunately, chromatic aberration is comparatively easy to correct. Assuming that this lens is made of crown glass, a lens of flint glass of the same size and shape would spread the blues and reds much further, although the focal point in general would not be much different. A negative lens of crown glass would spread the light in the opposite direction, with the reds closest to the lens and the blues further away. And, a lens of flint glass would also spread them in the oppo- site direction, only still further apart. So, to correct for chromatic aberration (Fig. lOA), we take advantage of these properties and combine a crown glass positive lens with a flint glass negative lens, which brings the blues and reds to- gether but makes a combination of a little longer focus. Here again only two colors can be corrected for with two glasses; the others still are out, and it is customary to correct for the two bright- est colors. Some high grade photographic lenses have three glasses and correct for three colors. Calculation Curvature of field must be corrected for (Fig. 11), to bring the outer edges of the picture in focus on a flat screen when the center is in focus. There are also the problems of astigmatism, comn, distortion and others which we shall not go into at this time. It is frequently asked from what point Ho 8 M r No.lOA 'M' I N5^trs^===^___ ■ i^^^ii2=- — ■ ^ No. 10. 12 INTERNATIONAL PROJECTIONIST February 1932 does one measure to get the focal length of a lens — from what part of a con- denser lens and from where on the barrel of a projection lens. The answer is gen- erally: from somewhere inside the glass of a condenser and from somewhere be- tween the two combinations in a projec- tion lens. When dealing with very thin lenses we may consider the lens as a line (like that in Fig. 12), and make our measurements from the center of the lens. While we are considering this drawing, I might de- scribe briefly the point-to-point method of locating an image from an object. Just two simple rules are used, and while the problem can be very complicated, in this case the application is easy: 1. Horizontal rays always refract to the focus 'CIMARRON' HEADS TEN BEST POLL Setting a new record for the number of votes received by an individual pic- ture, "Cimarron" ran away with first place in the list of Ten Best Pictures of 1931, selected by the leading motion pic- ture editors and critics of the country in the tenth annual poll conducted by The Film Daily. Total ballots returned in this vote also set a new high mark of 339. Of this number, "Cimarron" received 273, against the previous record of 271 es- tablished last year by "All Quiet on the Western Front." The other nine pictures to win places were: "Street Scene," 200; "Skippy," 178; "Bad Girl," 172; "Min and Bill," 164; "The Front Page," 162; "Five Star Final," 138; "City Lights," 128; "A Free Soul," 114; "Sin of Madelon Claudet," 99. It is interesting and perhaps quite sig- nificant that practically all of these "ten best" pictures have a strong vein of hu- man interest — heart appeal. This un- doubtedly aided them in winning votes above other productions of higher artistic or technical merit but less emotional value. Another point worth noting is that five of the ten were based on stage hits. WASHINGTON CHOSEN FOR S. M. P. E. MEETING The Society of Motion Picture Engi- neers will hold its Spring Meeting in Washington, D. C, May 9-12, according to an announcement made by the Board of Governors of the Society. Washing- ton was selected by the Board of Gov- ernors following a majority vote for this city by the membership. W. C. Kunz- mann, Chairman of the Convention Com- mittee, and 0. M. Glunt, Chairman of the Papers Committee, will prepare the pro- gram of arrangements for the meeting which will be held during the height of the Washington Bicentennial activities. N. D. . Golden, assistant chief of the motion picture bureau. Department of Commerce, has been appointed chairman of the local arrangements committee. 2. Central rays pass through with- out deviation. The horizontal rays from the head of the arrow (Fig. 12), are refracted through the focus and the central ray passes straight through the center ; where the two meet is located the image of the starting point. Here is a diagrammatic representation (Fig. 13), of a compound microscope which traces the paths through the objec- tive lens and eye-piece lenses and shows the lenses as represented by straight lines, the particular shape of the glass making no diiference. In fact, lenses are designed from such drawings, and when the separation and focal points are de- termined so as to get the results wanted, then the shape of the glass which will be necessary to give the focal points at the places indicated is determined. But the lenses we use are not thin. They have considerable thickness, and before any calculations are made tlie nodal planes must be determined and measurements taken from them. Here (Fig. 14), are represented the approxi- mate nodal planes of the common forms of lenses. You will note that these nodal planes are as if the line used to represent the lens in the previous drawing (see Fig. 11), were slit in two and pulled apart — which is just what you would suspect that glass thickness might do. Referring to Figure 15, follow the course of the ray through the lens and note how the drawing made to the nodal planes gives the same result as to the glass surface — so that for purposes of calculation the actual shape of the glass need not be shown. Getting back to the question of from where are we to measure our lenses, the answer is: — in thick lenses we measure from the nodal planes; and if we keep these sketches in mind, we shall always have an approximate idea of the pro- cedure. The actual point would, of course, have to be determined from each particular lens (see Fig. 14). We have covered only a few of the simpler principles of lenses, but if these few points are kept in mind, I believe that the topic of the course of light will give you less trouble. I have not been logical. I began nowhere and finished nowhere; but if you are interested, per- haps I can give another talk bearing more directly on projection optics. OPERATING HINTS 1. Don't use force in driving pins or removing shafts. 2. In removing intermittent movement be careful not to strike the sprocket against the sides of the mechanism. 3. Don't let film trap door slam after threading, as the film may be thrown off the sprocket and ruined when the pro- jector starts. Place finger against trap door and let it close easily. 4. Don't use steel to scrape the emul- sion off the film trap and tension springs. Use the edge of a copper coin or other soft metal. Brass is okay. 5. Don't force your projector when it seems stiff. It may need oil, or an ob- struction may have found its way into the working parts — such as a loosened pin or screw. 6. Don't use alcohol, benzine, kero- sene or turpentine as a lubricant. A first-grade medium body oil is recom- mended. 7. Don't try to put enough oil into mechanism at one oiling to last a week; use less oil and use it oftener. 8. Don't forget any of the oil holes. They are there for a purpose and every one of them is important. Locate each of them on the instruction plates. 9. Don't fail to keep lenses and con- densers clean at all times. 10. Don't use a rough cloth or waste to clean optical units. A piece of chamois, linen or soft cloth moistened with ammonia will give the best results, and remove all dirt as well as giving a high polish. Use equal parts of am- monia and water. 11. Don't fail to examine all electrical connections on lamp, rheostat or motor. For any electrical device to be efficient all connections must be firmly tightened. 12. Don't allow water or any dampness to penetrate the rheostat or motor. 13. Don't fail to keep the commutator and brushes on the motor perfectly clean. 14. Don't neglect the arc lamp con- nections. High amperage eventually chars the asbestos leads nearest the lamp and efficiency requires careful attention to the connections. 15. Don't use oil or grease on lamp joints or rods. Use a little powdered graphite, or a grease graphite, at the joints. 16. Don't expect good results with dirty or pitted carbon jaws. 17. Don't run projector with maga- zine doors open. 18. Don't allow cold air draughts from a fan or other sources to blow into the lamphouse. Such a draught will in- variably result in condenser breakage. 19. Don't screw up condenser rings and holder tightly. 20. Don't fail to wash sprocket teeth at least twice a week with stiff bristled tooth brush dipped in kerosene. 21. Don't fail to match "0" marks when replacing intermittent. 22. Don't fail to keep pad rollers ad- justed to two thicknesses of film. 23. Don't bend the intermittent guide apron. To do so will cause serious film damage. 24. Don't forget to oil the take-up spin- dle. COMPARATIVE WORTH OF D. C. POWER SOURCES THE problems presented by the need for direct current in projection rooms are quite complex, and this complexity is emphasized by the ex- treme conditions imposed by the quality of the direct current desired. The photo- cell cannot tolerate a condition such that the direct current have a ripple one one-hundred-thousandth of its amplitude imposed on it. In other words, if the voltage of the photo-cell varied between 99.999 volts and 100 volts at a frequency rapid enough to be heard in the speaker, it would produce an objectionable noise. The photo-cell is the most important problem, but many others exist. Direct current must be supplied to the ampli- fiers, the exciter lamp, the speaker fields, and the arcs in the projectors. It is the purpose of this article to compare these various uses and the economy of the many systems employed to supply this direct current. Because of the various voltages em- ployed, a single source of direct cur- rent cannot be employed with desirable efficiency, since, if sufficient voltage were generated to supply the power amplifiers, about 500 volts, 98 per cent of the power would be lost feeding the exciter lamp, and the source would have to be filtered well enough to work the photo-cell and the first amplifier. Such a system would be too expensive, and would generate too much heat to be of definite commer- cial value. Instead we employ a dif- ferent unit for every purpose. Forms Employed This equipment may take different forms: it may consist of batteries, which supply the pure current; of generators, which have a high frequency ripple and Samuel Bagno What consititutes the most efficient source of D. C. power? Is it possible to se- cure both economy and effi- ciency in newly developed equipment? are driven by a single alternating cur- rent motor ; , or of rectifiers. The recti- fier, being an instrument to alter the di- rection of current flow so that instead of reversing itself periodically the current pulsates in one direction only, introduces a type of direct current that cannot be used directly. Like the direct current generator, its output must be filtered before it can be applied. The filtering process is a smoothing-over, that is, the pulsations are removed and a continual uni-directional flow of current results. A study of the character of the current fed to each instrument will enable us to select that type which is best for each purpose. Since every part of a sound projector is important, we cannot allot preferential consideration to any one unit. Instead we will consider them in the sequence in which they act. The exciter lamp must be supplied by voltages ranging from 5 to 10 volts, and currents ranging between 3 and 7^ am- peres, depending upon the type used. The pulsations of direct current may be one per cent, of the total without an un- due ripple resulting in the speakers. Good voltage regulation is essential. since the light generated by a voltage in- crease varies out of proportion to the voltage change. This light changes the volume of sound generated, and a 10 per cent, change in voltage may produce a 40 per cent, change in volume. An increase in voltage above the rated value of the lamp results in a decreased life. Where the regulation is poor, some in- strument must be inserted in the line of the exciter lamp to regulate the voltage within narrow limits. Storage Batteries Storage batteries supply a constant voltage without a ripple. Storage bat- teries, however, are cumbersome and re- quire a separate compartment or room. They are expensive and require con- tinual care. The overall efficiency of a storage battery system is high and com- pares favorably with the motor genera- tor and rectifier filter system in the mat- ter of current consumed. Storage bat- teries, however, must be charged, and the charging instruments are the very instru- ments that may be used to light the ex- citer lamp directly, namely, rectifiers and motor generators. Storage batteries act only as direct cur- rent filters and voltage regulators. As such they can be replaced by inexpensive filters that require no maintenance. The filtering does not have to be perfect, since the heat inertia of the exciter lamp acts as an additional filter to help smooth the D. C. The motor generator has the advantage of maintaining a constant voltage as long as the frequency of the alternating cur- rent is kept constant. The frequency of the alternating current varies about two per cent. Such a variation is not serious 1 uu 90 80 CO V^ c ' _ !i ^■^^^ M 1 * 1" "o 20 10 lOO 20O 300 AOO 5dO 600 700 aoo Fig. 1 — Life test record of copper oxide rectifier 2S Fig. 2 — Efficiency of a copper oxide rectifier designed for 1-volt operation [13] 14 INTERNATIONAL PROJECTIONIST February 1932 -if- , -12 1 / "iO 1 ?8 E < 6 " ...A •t / / f Vo\ts . 4 -3 -t -I 9 / t Vo»tS ^ 2 3 i- - 1 in 1 j 1 r / i / / ^ y' 0 20 40 SO 80 Left: Fig. 3. — Voluampere curve of 1.5 inch copper oxide disk. Right: Fig. 4. — Showing increase of current through the high resistance at constant volts and increasing temperature and can be reduced to a negligible figure by an additional winding on the field of the generator. The motor generator has the additional advantages of unlimited life and cheap upkeep. The ripple caused by the motor gen- erator is very small in comparison to the direct current generated. In spite of this, the filtering employed with such a generator must be effective, as the ripnle is of such a frequency as to interfere most with the reproduced sound. The commutator ripple, if permitted to come through the speakers, would give a con- tinuous shrill note of about 1,000 cycles. Also, it may be added, a motor generator system requires constant attention and continual lubrication, is not readily ac- cessible, and costs from two to four times the price of a rectifier filter unit. The ideal piece of equipment can be locked up, forgotten and be dependable enough to give continuous efficient ser- vice. Types of Rectifiers There are several types of rectifiers that can be used for low voltages, but the cuprous oxide rectifier is the most efficient and least expensive of the lot. Such a rectifier if properly used is inde- structible, requires no attention, and is highly efficient. It requires as auxiliary apparatus a transformer to step the volt- age down to the required level and a filter system to change the rectified pul- sating direct current to pure direct cur- rent. It is entirely noiseless and easily replaceable in case of a burn-out. While it is true that the direct current output follows the voltage fluctuations of the A. C. line, the voltage across the lamp can be kept fairly constant by the use of a constant voltage transformer or a ballast resistor. Cuprous oxide recti- fiers have proven their dependability in other fields, notably in radio and rail- road work, and there is no reason why they cannot work just as well in the pro- jection room. It may prove of some interest to study the action of a cuprous oxide rectifier. The rectifier is built around the action (first discovered some ten years ago), that cuprous oxide, a copper rust, when formed on a copper plate by heat will show a different resistance to the flow of electricity from the rust to the copper than from the copper to the rust. This action is not chemical nor in any way destructive to the rectifying element, but depends entirely on the crystaline struc- ture of the rust on the copper. These crystals can be altered by excessive heat and the rectifying effect destroyed. The ratio of resistance current flowing in one direction to the resistance of cur- rent flowing in the other direction is about 9,000 to 1. Figure 1 shows a life test average of a large number of rec- tifiers over a period exceeding two years. The units were kept on test twenty hours a day for eight hundred days — a total of sixteen thousand hours. This approxi- mates four years' use in a projection room. The results show a current drop of about 20 per cent, over this prolonged period. This may sound serious, but in actual practice it is less serious than it sounds. A rheostat may be used to keep the exciter lamp at a constant potential. The efficiency of such a unit after a nunr.- ber of years still compares favorably with a motor generator set, and its output is more constant than the light emitted from an exciter lamp at constant voltage. The next problem is the photo-cell. Here we want pure D. C. — nothing else will be acceptable. We are confronted again by the three applicants for the task of supplying power: Let us consider each on its merits: 1. The dry cell battery 2. The motor generator filter unit 3. The rectifier filter unit The dry battery presents an excellent case. Here we have a source of power that is free from any ripple. The life of a set of dry cells when supplying the negligible power required by the pho- to-cells is equivalent to the shelf-life of the batteries. Such a set if used continu- ously should last at least one year. This set is inexpensive and easily replaced. The filtering problem is also simplified by the minute amount of energy needed. Several resistors or chokes and con- densers can reduce the fluctuation be- low one part in one hundred thousand. The source of voltage can be the same source that supplies the amplifiers, and the only additional expense is the filter. The filter need never be replaced, and compares very favorably in cost with bat- teries. Therefore, although batteries are the ideal source of power, they are not as economical as a filter system supplied by the same source as are the amplifiers. Amplifier Supply The amplifiers need direct current to feed the plates of the tubes. They can be divided into two classes: the preliminaiy amplifier working directly from the pho- to-cell and supplying the power ampli- fiers, and the power amplifier that works the speakers. The amplifier problem is analagous to that presented in radio, and the results of many years of radio re- search and development have supplied us with rectifier tubes to meet our needs. These tubes are rugged and inexpensive and their guaranteed life is from six months to a year. A generator can also do this work, but, as mentioned previous- ly, it requires supervision, lubrication and very much additional space. The output of a generator requires more care- ful filtering because the ripple frequency presents much more unsatisfactory sound than does the output of a rectifier. If the commutator sparking is too great, the amplifier may pick up the sound in spite of the best filter available. It is also true that the ear response is several hundred times more sensitive to 1,000 cycles than to 120 cycles. When economy of operation is considered, the motor generator set is more efficient. But the saving is only a few cents a month, which is negligible. When all factors are considered, we find the recti- fier unit more desirable as a supply source for the preliminary amplifier as well as for the power unit. The fields of the dynamic speaker pre- sent a problem very much alike that of the exciter lamp. Here we desire direct February 1932 INTERNATIONAL PROJECTIONIST 15 current not necessarily entirely free from ripple, since the field of the dynamic speaker in itself acts as a choke. The current drain is from 1 to 3 amperes, and this value depends on the size of the the- atre. The voltage regulation is not at all critical, variations of 10 per cent, easily being permissible. This is due to the fact that after the field of the speaker becomes saturated with magnetism, a large variation in magnetizing current produces a small change in magnetic flux. The field coil of the dynamic speaker is used to supply a magnetizing force and thereby create magnetic flux. Besides the motor generator unit there are two types of rectifiers in general use for this work: the cuprous oxide and the tungar rectifier. The action of the cup- rous oxide rectifier has been explained previously. The tungar unit consists of a transformer and two tungar tubes. These tubes have been used as battery chargers for a good many years and have proven very successful for that type of work. However, the continued replace- ment of tubes that are rather expensive and that are rated for only 3,000 hours renders a tungar unit less desirable than an equally efficient oxide rectifier. A separate generator may be used for this work, or the voltage may be taken off the generator that supplies the ampli- fiers. The former is undesirable, because a generator for this purpose is not as economical in initial cost or maintenance as a cuprous oxide unit. The latter pro- cedure is undesirable, because for every 500 watts generated only 100 watts will be consumed in the fields of the speakers. For each of the purposes outlined above the rectifier is better suited. There is no question that a theatre which can get by with an incandescent lamp in the projector will find a, series of rectifier units better than a series of motor-driven generators. The rectifier units are more efficient, less costly, more accessible, and almost as durable. To this can be added the fact that rectifiers require no oiling or attention of any kind. Arc Requisites When we consider the arc lamp and its supply, we find a field best suited for the generator set but by no means limited to it. It is true that the majority of theatres employ motor generators to sup- . ply the D. C. for their arcs. Rectifiers for this purpose are comparatively new. The mercury are rectifier formerly used has been a misfit for this work. It is much more efficient at higher voltages, only economical above 500 V, and its care and expense make it unable to com- pete with the motor generator. In the last few years we witnessed a remarkable development in rectifiers. We now have rectifiers for this purpose which are more efficient than the motor generator set, cost less for service and maintenance, and involve a lower initial investment. The two types now on tlie market make use of cuprous oxide and tungar tubes. The tungar tubes will probably he replaced with the more durable cuprous oxide. The next few years will witnesses a more serious com- petition between the rectifier and the motor generator D. C. arc. Without doubt the rectifier will more than hold its own. The future will offer a compact and efficient electrical supply for the pro- jection room in the form of several small rectifier units. The motor geoierator supply set appears outmoded not be- cause it is inefficient but because it has become uneconomical. INTERNATIONAL PROJECTIONIST solicited comment on the foregoing article by Mr. Bagno and is pleased to present as an appendage thereto the following comment by well-informed work- ers in the field: Addenda: M . L. Robinson ROTH BROTHERS & COMPANY GENERALLY I take exception to Mr. Bagno's use of the phrase "storage battery systems," as one would gather from his employment of this phrase that the battery really acts as a filter. More specifically, I do not believe that the variation of A.C. fluctuation would be more than one-half of 1 per cent. Good practice demands a commutating frequency of 1,500 cycles for motor gen- erators used with sound systems, and a Roth generator set for such service would have at least that frequency for service. Any well-designed unit would be similar. Besides, this is a very easy matter to fil- ter in comparison with the lower fre- quency fluctuations of a rectifier. Rectifiers burn out and the transform- ers and resistors employed reduce effi- ciency and do not actually regulate for line fluctuations. In addition to line fluctuations, provision must be made for a constant drop in voltage. It may possibly be true that the ear response is so very much more sensitive to 1,000 cycles than to 120 cycles, but in any event the filter in the latter case would be far more expensive. We would expect our generators for sound sys- tems to have a commutator frequency too high to be objectionable. I believe Mr. Bagno's statements with reference to the ill effects of a commutator ripple are all wrong. It is significant, however, that he does admit a "slight saving" in favor of motor generators. Proof Lacking In regard to his statement concerning the copper oxide rectifier, what basis of proof has Mr. Bagno for stating that "they are more efficient, less costly, more accessible, almost as durable, and re- quire no attention"? As Mr. Bagno has never tested Roth motor generators for sound systems (and we have our doubts that he has tested other makes on the market), it appears to us that he is tak- ing the word of the companies making rectifiers for the statements he makes. Unless his rather general statements can be shown to be accurate, they should not be printed. The mercury arc rectifier is economical only above 500 volts and cannot begin to compare with a motor generator for the reason that it requires a great deal more care and is also very expensive. Earlier in his article Mr. Bagno ad- mits a slight saving in favor of motor gen- erators, but near the end in granting the advantage of a rectifier economy as com- pared with motor generators, he seems to be dealing with a rectifier as yet unde- veloped. His whole last paragraph, it seems to me, is pure assumption in of- fering as a statement of fact that which has not yet come to pass. In making the statement that the mo- tor generator is doomed because its use is now uneconomical, he submits no proof to back up his contention. We regard this as a very unfair statement, as it is obvious that such a statement should not be made unless Mr. Bagno really has en- gineering data based on the performance of the leading motor generators now be- ing used in the industry. His article may prove of some value in the way of general information, but one who knows something of the prac- tical application of these various units will undoubtedly have a number of ques- tions to raise. His statements about other than cuprox rectifiers are distorted, we believe, and may have the opposite ef- fect to that desired. Anonymous [Note: The folloiving opinion is the contribution of a director of projection for a large theatre circuit — Editor.] AS early as the second paragraph of Mr. Bagno's article I find myself in disagreement with him. He positively as- serts that direct current must be sup- plied to the photo electric cell, amplifier, exciter lamp, speaker fields, and arcs, and then he immediately states that his {Continued on page 31 j WANTED: A NATIONAL SOCIETY OF PROJECTIONISTS James J. Finn SOMETIME ago we pointed out the urgent neces- sity for a national projectionist society — an organiza- tion which, while having its roots in the various International Alliance local unions, would give that cer- tain stabilizing social and educational force so lacking in unions today; that certain something which, however re- luctant we may be to admit it, the labor union does not and probably never will give. The shortcomings of the union in this respect may occasion considerable surprise among a majority of people who instinctively associate fraternalism with a labor union. The reason why this should be so is not hard to find. Labor unions have made a fetish of establishing wages and working conditions — so much so that the fraternal aspects of a union have been permitted to be slowly pushed into the background, obscured and, save for the time- honored "fraternally yours" appended to correspondence and the like, obliterated. Memhers have taken their cues from the unions' officers in the matter of regarding the' union merely as a business clearing house. Particularly is this true of the larger city unions. A majority of union leaders will reply to this argument that they are running a labor union and not a girls' school. This is a fallacious argument and quite silly in these days of enlightened thought. Developing Craft Morale A labor union must contribute more to and be thought by its members to stand for something more than merely a clearing house for the union's business. Labor unions might well take a leaf from the books of the large corporations in America today in seeing to it that their members' social and educational needs are adequately cared for. Unions can never expect to receive from their mem- bers that loyalty so necessary to the successful conduct of the labor union unless they in turn give something to the members which will inspire that loyalty. That loyalty will never be forthcoming so long as the members regard their unions merely as business clearing houses. With unions tending only to the purely physical needs of their members it is but natural that the members should think of the union in economic terms only. Apart from the work of socialization, the formation of a national projectionist society would net the union other and vastly important returns. There is the matter of edu- cation and also the matter of adequate representation in the councils of the industry in which the union operates. We shall first consider education. The number of local unions of the I. A. now engaged in educational activities for their members is so small as to be insignificant — and this in defiance of definite charter and constitutional requirements. If labor unions would stop and reflect upon their modus operandi, they would quickly come to the conclusion that that which they are selling is not organization, union labor as such, or any much-discussed but actually non-existent commodity, but merely a guarantee of better work. The day when a man can think of his job in terms of the measure of protection afforded him by his union card is gone — definitely. We have often said that a union, particularly an I. A. union, must display as much interest in and enthusiasm for the educational features of the organization as it does in the matter of wages and conditions. All this is so very elementary that there would seem to be no need to set it down here; yet there are many who would resist any attempt to popularize such a program. Projectionist unions have but one thing to sell, and that one thing is superior work. And superior work can be had only from competent craftsmen. Competence can be attained only through study and training, and it is this which is primarily the function of the union. An educational program will pay rich divi- dends. Only a national society can provide such a service. Adequate Representation What is this thing so loosely phrased as "adequate repre- sentation in the industry" which we mentioned previously? Just this: projectionists are just as much a part of the motion picture industry as are actors, directors, cinematographers, studio workers, manufacturers, dis- tributors, exhibitors, and executives. Their contribu- tions, while probably not as large as some other groups in a strictly monetary sense, are none the less tangible. Projectionists have a large stake in the industry, and they should be represented in those councils which have a bearing on their work. The introduction of the Standard Release Print and, lately, the new standard aperture provide concrete ex- amples of the need for an alert projectionist organization. Projectionists should be consulted on such matters for the simple reason that they are in a position best to know the technical requirements as well as being the group which has to put into operation any such plan. Had it not been for the American Projection Society and the Projection Advisory Council, projectionists would have heard about the S. R. P. only when they handled the first S. R. P. print. Imagine! It reflects no discredit upon the managers of societies like the American Projection Society and the Projection Advisory Council to state that both organizations have failed miserably to accomplish that which they had hoped to do. The reason for their failure is all too apparent: lack of support on the part of projectionists. Projection- ists as a craft are notoriously indifferent to any attempt to render them a service. They will take all they can get in the way of such service — ^that is, provided it is brought [16] February 1932 INTERNATIONAL PROJECTIONIST 17 to their bedsides on a tray. Cooperation is assumed to be the keynote of the labor union, but we are beginning to suspect that projectionists don't know the definition of the word. We repeat: the A. P. S. and the P. A. C. had good merchandise to sell, and the men who were selling this merchandise were earnest, self-sacrificing, and hard work- ers. The support accorded these men was at best meagre; in fact, their efforts were often subject to sniping from the indolent sideliners. Who will say no? Other Organization Affiliation We hear a lot of talk about the Society of Motion Picture Engineers and the Academy of Motion Picture Arts & Sciences. Who will say that either or both of these organizations can serve the projectionist in the manner previously outlined? The bare statement that we hear a lot about these organizations is in itself a tribute to the value of organization in that their publicity bureaus are functioning. But no publicity bureau is functioning for the projectionist for the reason that he himself makes it impossible. Let's face the facts: Neither the Academy nor the S. M. P. E. can give the projectionist one one-hun- dredth of that which he would receive from his own organization. Projectionists owe allegiance first to their own organizations. Yet we have seen the very same projectionists who dis- dain the opportunity for rendering their own craft a ser- vice labor long hours on an S. M. P. E. committee and stretch themselves out in an effort to please. To please whom? It's a funny thing, this glamour of a name. Talk projection or projectionist to these men and they are not mterested; talk S. M. P. E. or Academy and their hearing suddenly becomes very acute. Projectionists themselves are in large part responsible for this condition. Imagine the spectacle of an organization, one local unit of which can raise a quarter of a million dollars overnight, not spending one cent for educational pur- poses. We never heard of such a thing. For shame! l\ow Is the Time for Action The time has come for projectionists to consider seri- ously this whole matter of a national society. Just thinking about it will do no good at all. Societies cost money to operate, and unless projectionists come across with the hard cash there is not a chance in the world of ever putting the plan across. How much would it cost? We should say that for not more than one dollar a year for each man in a direct tax to national headquarters (irrespective of local unit costsj, projectionists would have just about the finest society in existence — a ' society that would amaze everyone by the quality of service rendered and would pay fabulous divi- dends in increased prestige for the craft. Who will welch for one dollar? Probably no one; but there must be something more involved than the mere giving of one dollar. There must be recognition of the fact that projec- tionists are a very important part of this motion pic- ture business and also an earnest desire on the part of the members to see their craft gain increased prestige and importance. Freely translated, this added prestige means a more secure livelihood and higher monetary returns. The task is too difficult, do we hear? Nonsense. Any craft that can boast of such men as Harry Rubin, R. H. McCullough, Chauncey Greene, Lester Isaac, Victor Wel- man, Frank Seavier, W. G. Woods, M. D. O'Brien, Thad Barrows, George Edwards, F. H. Richardson, Jesse Hop- kins, C. A. Dentlebeck, Sidney Burton, C. Curie, William S. Roberts, Lawrence Katz, and a host of others who have worked for the interests of the craft in the past — we repeat, any craft that can boast of such men need have no fear of a difficult task. Be somebody in your own business — even if you are forced into it! DAMAGED FILM: DEFICIENT EQUIPMENT AND THE RESPONSIBILITY THEREFOR JUST one of those things that are happening every day in this industry of ours and to which no importance would be attached by nine out of ten editors was the recent arbitration case of Columbia Pictures Corporation against the Jersey City Theatre. The matter at issue was an old story — film mutilation; but the method of proced- ure in trying the case and the decision rendered are of far-reaching importance. Briefly stated, the case was one in which Columbia asked to be recompensed in dollars and cents for damage done to one of its prints — ostensibly in the Jersey City Theatre. Columbia contended that the print was in per- fect condition when delivered to the theatre; the theatre submitted a defense which consisted of the bare statement that the print was not in good condition when received. We assume that Columbia introduced in evidence its exchange records on the print in question and that the Arbitration Board accepted these records at face value. This procedure is of small interest to us. That which does interest us very much, however, is the fact that the Board decided in favor of the plaintiff (Columbia), and the theatre was asked to pay for the print — in dollars and cents. It is conceded that the testi- mony of the projectionist who was called as a witness was the hinge upon which the case turned — ^this and the fact that the theatre was privileged to return a defective print and ask for another. This stuff of a theatre returning a defective print and requesting another is all nonsense. If they had returned it, the exchange might have told them they "were crazy" or given some other such enlightening answer; and the chances are that the theatre didn't have sufficient time to do this before the show opened. Such is our distribution system in this business that a can of film is often hurled 18 INTERNATIONAL PROJECTIONIST February 1932 against the door not more than fifteen minutes before show time. In cold weather, such a delivery system pro- vides a juicy morsel for a high intensity lamp. A "Very Reluctant Witness" We are informed by Louis Nizer, attorney for the New York Film Board of Trade, that the projectionist proved a "very reluctant witness" (for obvious reasons, we say), but that he finally admitted that dirt or dust gathered in the aperture could and often does scratch the film, as would defective equipment in the nature of worn sprockets, uneven tension, and other things. The aperture business, however, seems to have carried the day for the plaintiff. It seems to us that this is a slipshod manner in which to decide such a case. Mr. Nizer is known to us to be an excellent attorney and he undoubtedly is to be congratu- lated on the score of recalling that a clogged aperture can and does scratch film. But so many things enter into a case of this sort, including the nature of the film stock itself and the manner in which it was handled, that it seems wholly unfair to decide a case upon such sketchy evidence. Expert testimony by one who knew something about film, equipment and mutilation might have changed the whole complexion of this case. The important points brought into relief by this case are (1) the theatre's responsibility to provide equipment in good working order; (2) the distributor's responsibility to provide the exhibitor with an opportunity for close inspection of a print; (3) the projectionist's responsibility to the theatre in keeping the equipment in good working order; and (4) the union's responsibility in seeing to it that there is a man on the job who is competent in pro- tecting the exhibitor's interest. (It will be seen that we have finally worked around to the thesis of the preced- ing article in this section.) The lessons to be learned from this case are plain — very plain. Mr. Exhibitor has learned that of two means of effecting economy that of paying — in dollars and cents — for dam- aged film is not the easiest way out. With the same defec- tive equipment the incident might recur again and again, and the bills for damaged film come in again and iagain. Mr. Distributor must be taught that he has some re- sponsibilities in this matter, in the way of considering the quality of film stock, inspection and handling in the exchange, and, finally, a delivery system which will give Mr. Exhibitor a chance to see what he is getting. Not to mention the h.i. lamp angle. The Projectionist Angle Mr. Projectionist might learn the value of insisting that worn parts be replaced and also that careful, periodic attention to fundamental maintenance details is highly important. The Local Union should learn that it is its responsibility to supply a projectionist who is competent in all these details. Suppose Mr. Exhibitor should tire of paying these film mutilation bills and should attempt to pass them along to the projectionist and to the Local Union? What a howl would rise to the heavens! But, say we, why all this excitement ? Just pass along the matter to that non-existent national projectionist society which we were discussing only very few minutes ago. The SOCIETY will battle valiantly for the projectionist — that is, when it is organ- ized with all the dollars it receives from projectionists. We hope no one is injured in the crush to pay his money. We invite the attention of Mr. Nizer of the New York Film Board of Trade to this little story; also, we ask Mr. A. S. Dickinson of the Hays office to consider the matter a bit. Projectionists and local unions get the idea right away, we are sure, thus we shan't have to make a special plea for their attention. This one case provides more "meat" relative to the matter of film mutilation than all the learned discussions we have ever listened to or read about. This is not "com- mittee business"; this is the real thing. ALL AMPLIFYING EQUIPMENT REQUIRES CARD MAN ON several ocacsions it has been called to the attention of the LA. General Office that traveling companies have been moving about the country car- rying amplifiers, etc., and getting by the local unions without having placed a member of the Alliance. Naturally, when they arrive at the next stand and are informed of LA. requirements, they relate the position maintained at the pre- ceding point and strenuously protest, feeling that they are being imposed upon. Indifference, neglect or unfamiliarity with the International By-Laws may be responsible for this condition, which was brought to the attention of the Delegates at the Thirtieth Convention in Los Ange- les, in the form of Resolution No. 13, which was unanimously adopted. As this type of attraction appears to be increasing in number, special attention is invited to the following resolution adopted at the Los Angeles Convention: To the Officers and Delegates of the 30th Biennial Convention of the I. A. T. S. E. & M. P. M. 0. of the United States and Canada: BE IT RESOLVED ,That Article 5, Section 4, Page 55 of the By-Laws, which reads as follows: "Any vaudeville act carrying stereop- ticons, spot, flood or effect lamps (such as waterfall, fire, cloud, lightning effects, etc.) or sufficient other electrical appa- ratus, shall be required to employ a mem- ber of this Alliance to care for and op- erate such equipment," be changed to read as follows: No Exceptions "Any vaudeville act carrying public ad- dress machines, practical radio sets, amplifying equipment, television appa- ratus, stereopticons, spot, flood or effect lamps (such as waterfall, fire, cloud, lightning effects, etc.) or sufficient other electrical apparatus, shall be required to employ a member of the Alliance to care for and operate such equipment." The provisions of the amended section are very definite and leave no question as to its intent of just what type equipment is implied, as it distinctly states amplify- ing equipment. CELEBRATE INJUNCTION VICTORY Local 203, of Easton, Pa., held a "Vic- tory Banquet" in Easton, on January 16th, to celebrate its victory in an in- junction fight with a local theatre. The Easton fight was of much interest to organized labor in that it marked the first case to be tried under the new Penn- sylvania injunction ruling, which gives the defendants the right to a hearing before a temporary injunction is granted. Among those present at the banquet were: William T. Richey, Pennsylvania representative of the A. F. of L. ; Fred J. Dempsey, I. A. General Secretary-Treas- urer ; Louis Krause, I. A. Assistant Presi- dent; I. A. Trustee, William S'canlon, Lynn, Mass.; Vice-President William J. Harrer, Philadelphia; Lawrence J. Katz, Secretary Fourth District; John Shana- han, B. A. Philadelphia stagehands local ; Lew Glendenning, Atlantic City local union, and James J. Finn. LAMP EQUIPMENT: OPERATION AND MAINTENANCE R. H. McCuIIough DIRECTOR OF PROJECTION AND ELECTRICAL EQUIPMENT, FOX WEST COAST THEATRES MOTION picture projection is a highly specialized art which has gone steadily and speedily for- ward; as it develops it is becoming more exacting in its demands. Good projec- tion is based on sufficient screen illumi- nation, good definition, and steadiness of the projected image. There is no excuse for discoloration on the projection screen, which is ordinarily caused by negligence in handling the projector arc properly. The successful projectionist studies pro- jection problems carefully, he is never over-confident, and during the picture presentation he gives the projected pic- ture constant attention. I have seen many projected pictures with shadows, which appeared to be a projection fault. The experienced pro- jectionist is very capable of determining projection faults at a glance. The most serious general problem of today is that many theatres are not adequately equipped so as to provide sufficient screen illumination. However, I find many the- atres with the best of equipment and yet the screen results are very poor. Projec- tion screens are not given enough atten- tion. We all know that projection screen surfaces should be inspected from time to time. Dirty projection screens should be cleaned immediately and, if necessary, the surface should be re-finished so as to insure good projection. Carbons Old-timers will remember the trouble which was encountered occasionally with the old-style projector arcs travelling or wandering, especially when using high amperage on D. C. In those days it was common practice to use a regular cored or solid negative carboti which was slightly smaller than the positive carbon. The operation of this arc required great skill. The introduction of the Silvertip negative carbon in those days was a great relief to many projectionists. With the use of the smaller diameter carbon, cov- ered with a metal application, a much steadier arc could be maintained. The reason for applying metal over the en- tire outside surface was because a carbon of small diameter, such as the Orotip, without a metal application would not carry the current. It has been my experience that by care- fully analyzing each complaint most troubles with carbons can be traced to the operating conditions. Projector arc lamp housings should be cleaned before the start of the daily performance. AH parts of the projector lamp should be kept thoroughly clean at all times and the projectionist should carry out the instructions given by the manufacturer as to the lubrication of certain working parts. Carbon jaws and carbon brushes should be inspected and cleaned at regu- lar intervals, so as to prevent corrosion. All electrical connections should be kept perfectly tight. The projectionist should be positively sure that he is using carbons of the proper size, so as to obtain the most illumination possible with the amount of current that is being used. When carbons are overloaded, they will spindle and needle. When the positive carbon needles, due to excessive over- load, the crater area will be reduced. If more illumination is required and the projectionist raises the amperage above the rating of the carbon, thus causing the carbon to needle, it is very clear that the electrical energy will be wasted. Spin- dling and needling of carbons may also be caused by poor carbon jaw or brush con- tacts. The ammeter (connected to the arc circuit), reading should be vertified occasionally so as to ascertain if the read- ing is correct. L. I. Reflector Lamps This type of projection lamp, with the positive and negative carbons set in a horizontal position, has given very little trouble. The ordinary 12 mm. x 8" posi- tive carbon, and the 8 mm. x 8" nega- tive carbons for horizontal trims, are rated for a maximum of 25 amperes. If the amperage for these carbon sizes of ordinary manufacture are increased to 30 amperes, the arc will be very unsteady at times and will require considerable at- tention— also, the carbons will spindle and needle. The low intensity horizontal reflector arc is very sensitive to draughts of air due to the fact that the current employed is considerably less than that used in any of the other types, resulting in the emis- sion of a comparatively weak arc stream. The exhaust vent for this type of a lamp- house should be so regulated by the use of a damper in the duct directly above the lamphouse that the arc will not be extinguished. Carbons are obtainable for the low intensity reflector arc lamp ' whereby this lamp may be operated with 30 or 40 amperes with satisfactory re- sults. I have found that mirrors supplied by reliable manufacturers will stand the in- crease in temperature rise if it is found necessary to increase the amperage to 40 amperes with the low intensity reflector lamp. It is needless to say that the mir- ror reflector requires constant attention in regards to cleanliness. This mirror may be cleaned by breathing on the sur- face, while it is cold, and then wiping and polishing with a very soft clean cloth while still damp. This method will be found to be satisfactory. A solution of equal parts of wood alcohol and water will be found to be effective for cleaning mirrors. A dirty mirror will naturally re- duce illumination, therefore, they should be inspected quite frequently. Many theatres on the West Coast have converted the low intensity reflector lamp OVERLOADING OF CARBONS AN operating fault which is common, not only to high intensity lamps, but to all lamps, as well, is the overloading of carbons. Carbons, like other manufactured articles, have physical limitations. If a carbon designed for 100 amperes is burned at 130 amperes, the natural result is short life and spindling. If carbons are spindling, the first move should be to check the amount of current drawn at the arc. It frequently happens that the ammeters have not been calibrated since they were installed, and as a resuh are not reading correctly. This is no reflection whatever on the make or type of ammeter in use as ammeters are very sensitive and consequently require attention from time to time. Ammeters off as much as 20 amperes, have been found. If your ammeter has not been checked for some time, it is suggested that you have the power company supplying your current check the current at the arc for you. [19] 20 INTERNATIONAL PROJECTIONIST February 1932 from a 25-ampere lamp to a 75-ampere lamp. A special preparation is used on the back of the mirror so that the mirror will withstand a high degree of heat. The negative carbon holder is changed to accommodate the increased amperage when converting this lamp. Two clamped type carbon contact brushes are installed within 2 inches of the arc, which sup- plies current to the positive carbon. The carbons used after converting this lamp are 11 mm. x 20" hi-intensity for the positive carbon, and 11/32 x 9" Oro- tip for the negative carbon. The lamp works identically the same as the low in- tensity reflector arc with the exception of the increased amperage. The positive contact brushes are located so that a length of 2 inches of the positive carbon carries the current load between the con- tact brushes and the positive crater. A shutter is installed between the arc and the mirror so as to protect the mirror while the arc is being struck. With the use of the hi-intensity car- bons, the light received from this lamp is a bluish-white similar to the light ob- tained from other hi-intensity lamps. .1 do not recommend the conversion of the low intensity reflector lamp to a make- shift hi-intensity reflector lamp. H. I. Reflector Lamp This type of projector lamp has given very good results. An air-cooled hi-in- tensity reflector lamp operating at 85 amperes will provide 14 foot-candles of illumination over a screen area of 600 square feet — which is satisfactory illumi- nation for a sound projection screen in a theatre with a seating capacity of 2,500 seats. This lamp when operated at 85 amperes produces approximately 1,200 degrees of heat at the projector aperture. Rear shutter attachments which will re- duce the heat at the aperture by 50 per cent, are absolutely essential when using these lamps, otherwise the heat at the aperture will cause the film to buckle and will also cause the component parts sur- rounding the aperture to become warped. The hi-intensity reflector lamp requires considerable attention. I have found if the manufacturer's operating mainte- nance instruction are followed carefully, this type of a projection lamp will last indefinitely. The carbon consumption and wastage is excessive, when using the hi-intensity reflector lamp. However, since carbon economizers have been per- fected for this lamp, carbon wastage has been reduced by about 15 per cent. The mirror reflectors for these lamps also re- quire constant attention with regard to cleanliness. This lamp is very efficient and pro- duces very good results. The amperages range from 110 to 160 amperes with this type of lamp at the present time. Recent developments in the optical system of the hi-intensity lamp has again made this lamp the most popular lamp for projec- tion purposes. By installing a larger col- lecting lens of 6%" in diameter and a front condenser lens of more converging efficiency of 7 3/7" in diameter, using 120 amperes, the results obtained are far superior to those obtained by using 160 amperes with a 4%" x 6%" rear con- denser lens and a 5" x 9" front condenser lens. Condenser Breakage It is imperative to use the hi-intensity lamp where the Magnascope and other large screen sizes are being used so as to obtain the correct amount of screen il- lumination. Many theatres are using the sphero-cylindrical Sy^' diameter collect- ing lens with the front converging sphero- aspheric 6" in diameter condenser lens. This is a condenser combination which is .manufactured by one of the leading lens manufacturing companies. I used this condenser combination during the presentation of the Fox Grandeur pro- ductions Happy Days and The Big Trail. This condenser combination produces a rectangular or oval spot at the aperture, which is necessary when projecting 70 DUO VAC TUBE CHARACTERISTICS Table showing essential characteristics of Duovac tubes used in sound reproducing equipments Fila- Plate Supply Type Use Filament Supply ment Current Amjeres Volts Grid Bias Detec- 1 Ampli- D.C. on A.C. on tor fier Fil. Fil. Detector 5.0 V. 90 4.5 DX-112-A Power A. C. or 0.25 45 135 9.0 11.5 Amplifier D. C. 180 13.5 15.0 Power 5.0 V. 135 27.0 29.5 DX-171-A Amplifier A. C. or D. C. 0.25 180 40.5 43.0 Power 7.5 V. 250 18.0 22.0 DX-210 Amplifier A. C. or 1.25 350 27.0 31.0 D. C. 425 35.0 39.0 Radio 2.5 V. DY-224* Frequency A. C. or 1.75 180 1.5 1.5 Amplifier D. C. 180 3.0 3.0 2.5 V. 90 6 6 DY-227 Detector A. C. or 1.75 45 135 9 9 Amplifier D. C. 180 13.5 13.5 7.5 V. 350 59.0 63.0 DX-250 Power A. C. or 1.25 400 66.0 70.0 Amplifier D. C. 450 80.0 1 84.0 A. C. Plate Voltage DX-281 Half-Wave 7.5 V. 1.25 (Max. R. M. S.) 700 Rectifier A. C. D. C. Output Current (Max. M. A.) .85 Audio 1.5 V. 1 1 D-264-A Amplifier D. C. .300 90 4.5 Audio 5.0 V. D-205-D Amplifier A. C. or D. C. 1.65 350 20. 22.5 Audio 10. V. D-242 Amplifier A. C. or D. C. 3.25 1,000 50. 55. A. C. Voltage per Plate (R. M. S.) .350 DX-280 Full-Wave 5.0 V. D. C. Output Current Rectifier A. C. 2.0 (Max. M. A.) A. C. Voltage Per Plate (Max. R. M. S.) D. C. Output Current .125 ..400 - (Max. M. A.) ..110 'Has screen gria voltage of 75 and 90 [This table prepared exclusively for International Projectionist] February 1932 INTERNATIONAL PROJECTIONIST 21 mm. film. I find, however, that this con- denser combination is unnecessary when projecting 35 mm. film. I have encountered very little trouble with condenser breakage with the use of hi-intensity lamps. If the projectionist is careful when striking the hi-intensity arc, and makes sure that the inside dowser is closed, this will protect the condenser lens considerably. The lamp housing should be well ventilated, which will also prevent condenser breakage to a certain extent. The rear condenser over a period of time becomes badly pitted from the metal particles from the projector arc carbons. I have been using heat-resisting condensers in all hi-intensity lamps. These condensers may be re-surfaced by any good reliable glass company, thus re- moving all pits from the surface, at a price of 7c each. It is also possible to use a piece of Ignal Heat Resisting Glass, so as to protect the rear condenser lens. When this glass becomes badly pitted it may be replaced with a new piece of glass. Carbon consumption and also carbon wastage is very excessive when using the hi-intensity lamp. Car- bon economizers are now being manu- factured for the 13.6 mm. carbon and also for the 16 mm. carbon which will effect a considerable saving. The care of the hi-intensity lamp posi- tive contact shoes is very important. A very fine grade of emery cloth should be used to clean and polish the contact sur- face of these brushes. As these brushes are formed to the size of the carbons used, it is important to retain this form. I have found that the best and the easier method for cleaning and polishing the positive contact shoes is as follows: Use a spindle of the same diameter as the carbon, bored so as to fit an ordinary film rewind. This spindle should be slotted so as to accept the insertion of a piece of fine emery cloth. The contact brush to be cleaned is held by hand against the emery cloth, which is fastened to the spindle. By operating the rewind the brush is cleaned and polished as de- sired. I have found that if this method is used for cleaning the contacts of hi- intensity lamp brushes, less emery cloth will be required. Hi-intensity lamps, like all other manufactured equipment, have physical limitations. Cleanliness and good care will govern the life of this equipment. EMERGENCY M.G. HOOKUP M. D. O'Brien Assistant Director of Projection, Loew Theatres IN some states the unreliability of the three-phase alternating current is so pronounced that certain theatres have found themselves without current for op- erating their motion picture projection generators, in some instances for periods of as much as an hour. This condition has been partially over- come by the installation of tremendously expensive storage battery equipment ; but in the case of the smaller theatre, which cannot afford this expenditure, a simple plan may be utilized to practically assure the theatre of constant operation under any emergency. If the present motion picture projec- tion generator equipment is operating on three-phase, and if single-phase current is available, an emergency motor genera- tor set can be installed to operate off the single-phase lighting circuit and thus keep the show going until such time as the three-phase current has again been provided. The accompanying blue-print shows an actual condition where two multiple-type motor generators were installed on the three-phase [or, in this particular in- stance, two-phase], power circuits, and a smaller series type single-phase motor generator was installed on the lighting circuit. This single-phase motor gen- erator has paid for itself many times over in guaranteeing continuous projec- tion and an uninterrupted picture on the screen during a period of failure of the two-phase circuit. In the event that the theatre is not wired with sufficiently large lighting feed- ers, a smaller motor generator than that which is used for the regular picture may be employed. This will, of course, cut down the screen illumina- tion, but it will at least avert a refund at the box office. All r&eoBtetB (7J to be oonneeted- to Bvs. Side '4^#e Asbestos Corered Z Phase. 3 #S/0 in t" Sohematio diagram for use of an 2^*? ^*"«i» phase emarganoy single-phase m.g. where '^/° ^ 2" coadm^**"^'* "'* two multiple-type generators are ^"^ in use oh regular 3- or 2-plias» power oirouits 22 INTERNATIONAL PROJECTIONIST February 1932 NEWS and VIEWS A collection of random thoughts, and some not so random; fact, fancy and opinion pertaining to the projectionist and pro- jection matters. The free-for-all forum. Lower Insurance Rates EXHAUSTIVE investigation of present working conditions in projection rooms has resulted in a lowering of rates on life insurance for projectionists by the Central Life Insurance Company of Cincinnati. The findings of this company probably will be reflected in similar re- ductions by practically all insurance com- panies. The savings affected are shown in the comparison of old and new rates which follows: Old Rates Class A— Licensed Projectionists: Extra rating $2.50 per thousand. Standard double Indemnity and waiver of premium clauses. No term insur- ance allowed. Class B— Unlicensed Projectionists: Extra rat- ing $5 per thousand. Standard double indem- nity. Double premium for waiver of premium clause and no term insurance. New Rates Class A— All licensed projectionists who use modern equipment and who are employed by the major circuits, namely, RKO, Fox Publix, Loew, and Warners, will in future be charged standard rate of premium. Also standard rate for double indemnity and waiver of premium clause. There will be an exception, however, on term insurance. Class B— Unlicensed Projection'.sts. Extra rat- ing $2.50 per thousand. Standard rate for double indemnity. Standard rate for waiver of pre- mium but no term insurance. The investigators were convinced that projectionists working in present-day theatres should not be subjected to an increased rate, the general opinion being that no special hazard is incurred in such theatres. While the deciding factor is the condi- tions under which the men work, it is apparent that the terms "licensed" and "unlicensed" are very ambiguous as here applied, as is the phrasing "modern equipment." Just what constitutes "mod- ern equipment"? Also, there are a great many circuit theatres that couldn't begin to compare in the matter of modern equipment and advantageous working conditions with any number of smaller and unaffiliated theatres. Under the new plan the later group undoubtedly is being discriminated against. The task facing the insurance com- pany with regard to setting a fair rate is not an enviable one, for, in order to be wholly fair they would have to investi- gate the working conditions of every ap- plicant. However, it does seem as though a better interpretation of what constitutes modern equipment could be drawn and that some provision be made for the up- to-date unaffiliated theatre. Projectionists are indebted to Mr. A. S. Dickinson of the Hays office and to Mr. J. E. Firnkoess of the RKO Palace Theatre, Cleveland, for their cooperation in this matter. A Bow to Kansas City GEORGE A. YAGER of Salt Lake City Local Union 250 writes in to say that credit given his local for a model newspaper advertisement in our November, 1931, issue should be appor- tioned as follows: The heading was taken from an ad. which appeared in the Kansas City Star in connection with a safety campaign inaugurated by Walter S. Croft of Local Union 170. The body of the ad. was taken from an idea gained from material of the Lancaster, Pa., Local Union, as was also the slogan "Silently, Safely, We Serve You" .... Well, better late than never. Mr. Crabtree on Halation OUR curiosity aroused by seeing in an issue of that splendid publication International Photographer a picture of a cactus tree the arms of which were sur- rounded by a halo that looked suspicious- ly like halation, we proceeded to put Mr. J. I. Crabtree of Eastman Research Lab- oratories on the spot. Here is his inter- esting reply: .... The white line or halo surrounding the cactuses in the appended reproduction is typical of all back-lighting effects and is caused by re- flection of the sunlight by the fine prickles on the cactus. The surfaces of these behave like a mirror, and in the case of those which are in- clined at the correct angle, they reflect the rays of the sun into the camera lens. This effect is, therefore, not strictly one of halation which re- sults from image spreading. When a dark object is viewed against a bril- lian light source such as the sun, an effect simi- lar to halation is obtained which is caused by irradiation in the eye itself. The retina of the eye in this case may be likened to the photo- graphic film. Whereas the brain should receive the impression from the retina of a sharp line separating a bright area from a dark area, the brain receives the impression of a fuzzy line. This effect is well recognized in the literature on physiological optics. Whether we consider the light action on the retina to be a mere stimulus of the "rods and cones," or as a chemical reaction, under such extreme stimulation there is either a diffusion of the chemical reaction products or a transference of motion of the vibrating membranes to adjacent areas. Which means that we often see those things that do not exist, which may pro- vide a clue to those frenzied workers in the three-dimensional field. Third Dimension SPEAKING of three-dimensional mo- tion pictures brings to mind the ver- bal spanking administered to us by Hugo Lateltin, a member of L.U. 306 and a contributor of some really worthwhile material to these columns. Subsequent to S.M.P.E. Standards Committee O.K.'s ,590 x ,825 Projection Aperture THE Standards Committee of the S. M. P. E. has officially adopted the proportions of .590 X .825 as a standard theatre projection aperture size. These figures compare with the dimensions of .615 X .820 originally proposed by the Academy of M. P. Arts ajid Sciences as announced in the November, 1931, issue of Interna- TION.A.L Projectionist. The Society has communicated its decision to the Academy, and the matter is now in line for settlement. With regard to the 18° mean distortion angle which was stated previously to have been an arbitrary estimate, it is interesting to note that a survey conducted by International Projectionist of 84 theatres in the metropolitan New York area revealed an average pitch of 17.5, which justifies the earlier estimate. This survey, in- cidentally, represents the first attempt to definitely establish the angle of projection in a large number of theatres. In adopting the standard of .590 X .825, the S. M. P. E. followed the recommendations of the Practical Projection Committee, of which Harry Rubin is chairman, which thoroughly investigated all aspects of the situation, particularly with respect to the technical necessities of theatre presentation. The final decision with respect to the proposed new aperture standard is expected to be forthcoming within a month. February 1932 INTERNATIONAL PROJECTIONIST 23 a discussion the other day in our office (where by virtue of talking faster we dominated; the situation by sheer force and number of words), Mr. Lateltin re- tired to the shelter of his home and there, safe from our sharp tongue, cooked up the following blast: In the course of our discussion yesterday you expressed the opinion that in order to solve the problem of three-dimensional pictures it would be necessary to take into consideration the physiological characteristics of the eye. In sup- port of this opinion, you stated that motion pic- tures were only possible due to these physiological ■characteristics and that on account of the "slug- gishness of the eye" it was possible to "fool" the eye. You explain, therefore, the reproduction of motion pictures by saying that the present art is possible only because of the advantage taken of this deficiency of the eye. You also anticipate that the solution of the third-dimension will be proven to lie in this direction — that is, by a tech- nical trick which takes advantage of the physiol- ogy of the eye. This process of reasoning, although justified by the common explanation in textbooks, is not cor- rect, as it is based on a faulty understanding of the actual process of seeing motion. To solve the problem of motion in pictures, and also the problem of the third dimension, it is not necessary to depend upon "fooling the eye." All that is necessary is to duplicate the physical part of the complicated process of seeing motion or depth. When viewing motion in nature, the actual proc- ess which takes place is the same as in motion pictures, with the single difference being in the number of different pictures seen. While the motion picture camera takes relatively few posi- tions of an object in motion, the human eye re- ceives an infinite number. There is practically no interruption in the succession of pictures in see- ing motion in nature; while when viewing motion pictures this interruption is considerable. In both cases, however, the fundamental process of viewing remains the same. It is true that the viewing of motion depends upon a physiological characteristic of the eye in that in seeting motion the eye is "fooled." But this also applies to the act of seeing motion in nature as well as to the art of motion pictures. Motion pictures merely duplicate the physical part of seeing motion. The third-dimension will also in the same manner, that is by duplicating the physical process of seeing depth. Inasmuch as the advantage at the mo- ment is all with us, we had decided to let the foregoing be judged by our readers, but we shall permit ourselves one state- ment: By a devious route Mr. Lateltin (in his last sentence), comes back to what practically amounts to an endorse- ment of our position in that by stating that the trick will be turned "by duplicat- ing the physical process of seeing depth," he confirms our contention that "duplicat- ing" involves not matching but "fooling" the viewing apparatus of the eye. He cites further the analogy between two- dimensional and three-dimensional mo- tion pictures and admits that in the for- mer the eye is "fooled." We repeat, so will it be in any successful rendition of the latter. Newspapers and Labor THE passing of the New York World from the newspaper field marked also the passing of America's foremost daily newspaper labor writer and de- Convention to Columbus /^OLUMBUS, OHIO, has been chosen as the scene of the next (Slst) Convention of the International Alliance. While no details have been settled as yet, it is expected that the Convention will be held the latter part of May, as heretofore. Other cities which received consideration were Louis- ville, Kentucky, and Milwaukee, Wisconsin. prived the New York metropolitan area of the only newspaperman who knew "what is was all about," that is, in a labor sense. We refer to John J. O'Leary. Mr. O'Leary knew labor from A to Z ; and labor men knew him. When he sat down to write a labor story he had the facts, and the background of experi- ence and understanding, and the nerve to say what he thought. And the World permitted him his say, in fact, encour- aged him to say it. What a difference be- tween now and then. No newspaper in New York now has a man who knows anything about labor. The World-Telegram (Scripps-Howard) is now winding up its desultory warfare against a unit of the I.A., and it must be said that, whatever the merits of its stand in the matter, it has displayed lamentable ignorance of labor and the laboring man. After firing its blast against Local Union 306 in general, its leaders in particular, and the policy of the local union as a whole, it proceeded by conventional steps to work up a lather first against then President Canavan, next against Presi- dent Green of the A.F. of L. and then against the labor movement in general. We forget the terms employed to express this indignation on the part of the World- Telegram but we do recall that if they hadn't been silly they would have been what is termed vicious. It seemed to us that the newspaper was railing against hyprocrisy. Well, if the battle be not against labor but against hypocrisy, why start with Local Union 306? Doesn't the World- Telegram know that it and all of us are operating and living in a hyprocritical age? Within five minutes in either di- rection from our office we can reach more than 100 speakeasies. The city, state and national governments are reeking with hypocrisy, as are a large majority of our daily newspapers. More than 30,000 speakeasies operate in New York through connivance with the authorities. We mean through graft. Local Union 306's derelections as pictured by the World- Telegram are infinitesimal as compared with other larger and far more important circles in which this newspaper might operate. We have nothing to say with regard to the merit or demerit of that which the World-Telegram tried to do; but we do say that its labor outlook is perverted and its thinking twisted. One thing labor does stand for and that is majoriy rule, which cannot be said for government and news- papers. CLEANING SOUND SCREENS CONSIDERABLE misinformation re- garding the cleaning of sound screens has been broadcast recently, par- ticularly in house organs of motion pic- ture companies. Projectionists are in ac- cord as to the necessity for cleaning sound screens, inasmuch as perforations clogged with dirt result in very unsatis- factory sound. Some of the methods sug- gested recently, however, bring to mind the old bromide about the cure being worse than the disease, and not a few screens have been irreparably damaged as a result of improper cleaning methods. It is reiterated here that there is no satisfactory method of cleaning a sound screen, despite the claims of many manu- facturers that screens may safely be washed. Non-Uniform Results From the purely technical angle, it is impossible to wash a screen. The fabric itself is washable and can be cleaned very easily, but it is almost humanly im- possible to remove all of the dirt from so large an area as that of a motion pic- ture screen, evenly and uniformly, with- out leaving streaks. The question of cleaning resolves it- self down to the ability of an individual to remove the dirt uniformly from a large area. The particular cleanser used has very little bearing upon the subject as a screen can be washed with equal results with any realiable soap dissolved in warm water and the solution applied with a sponge and the screen rinsed off with clean water. Good results apply only to small areas, however. Every major circuit has devoted a great deal of time to cleaning of screens. Up to date the most satisfactory means found is to brush off the screen with a fine goat's hair brush at least once a week from the time it is installed. In this way the surface can be kept fairly free of dust. In case a vacuum cleaner is available, excellent results can be ob- tained by reversing the action of the cleaner and blowing the dust and dirt off the screen from an angle. Z^/it PATENT PAGE THE following digest of patents granted recently was prepared ex- clusively for International Pro- jectionist by Henry L. Burkitt. Mr. Burkitt, B.S. in ch. e., L.L.B., is a former Assistant Examiner in the U. S. Patent Office, a member of the Bars of New York, Pennsylvania, and the Dis- trict of Columbia, practising in New 'York City. Any reader desiring infor- mation on any patent, whether abstracted herein or not, or wishing to secure a copy of any patent listed herein, may secure same by addressing Mr. Burkitt in care of this publication. — Editor. Volume Control 1,827,735. Volume Control In Sound Record Reproduction, to James R. Bals- ley; assigned to Fox Film Corporation. In this sound control system using sound film, a separate record is moved synchronously with the sound record to produce electric currents and thus effect volume variations of the sound repro- duced from the sound record. This film control is associated with the gridplate circuit of a vacuum tube in such manner that the control currents may be modulated by the sound cur- rents. Automatic Disc Stop 1,828,171. Phonograph Sound Repro- ducer, to James R. Buchanan. Apparently this disc record sound reproducer has stop means for the turntable including a light-intercepting device which is moved by a screw, connected to the turntable drive shaft in such way as to stop the record at a certain point. It is not clear for what purpose light intercepting and responsive devices actually are provided. Condensing System 1,828,399. Photo-electric Cell Light Ray Condenser, to Charles W. Ebling; assigned to General Talking Picture Cor- poration. In a block which is used for guiding film past a photo-electric cell, is mounted a removable tube carrying a condensing lens. A slit is pro- vided for guiding rays to the lens. Vacuum Tube 1,828,545. Vacuum Tube and Its Ele- ments, to Samuel Ruben; assigned to Ruben Tube Company. A sealed evacuated envelope contains a grid, an anode, an indirectly heated cathode, and a heating element for heating the cathode. The cathode has a coating of alkaline earth oxides, and the filament is mounted upon a conductive member having a specific resistance greater than tliat of the conductive filament. Film Stopping Apparatus 1.828,569. Film Stopping Apparatus, to Edward W. Kellogg; assigned to Gen- eral Electric Company. The reel for the record film has a flange por- tion and a relatively rotatable hub portion upon . . . not *'clips^^ in wordy patent language but clear and concise abstracts prepared especially to meet the needs of readers of this publication. which the film is wound. Means respond to pre- determined unwinding of the film to stop fur- ther movement of the flange portion. Sound Screen 1,828,749. Motion Picture Screen, to Albert L. Raven. The screen is made up of a plurality of wavy horizontal strips, each arranged with its upper edges overlapping the lower edge of the next higher strip. The peaks of the waves are dis- posed opposite one another. Means secure the strips to one another at the peaks so as to pro- vide, between the points of attachment, numerous sound passages, extending upwardly from the rear toward the front of the screen. Sound Correction 1.828.941. System For Correcting Sound Records, to Roy J. Pomeroy. In this method, the original sound film is audibly reproduced. A distortion record of this reproduced sound is made by synchronously pro- ducing currents from the original and the dis- torted records, and the sound currents so obtained are differently combined so that the sound cur- rents are neutralized except for a distortion- representing current. The original record is then corrected by modifying it by means of the cor- rection record by the amount of and opposite to the distortion arising in reproduction. Sound Correction 1.828.942. Production Of Corrected Sound Records, to Roy J. Pomeroy. In this method, sound is recorded both photo- graphically and mechanically. The mechanical record is then audibly reproduced and a repre- sentation of the distorted sound thus produced is differentially Combined with a representation of the original sound to get a distortion recor.l. The original photographic sound record is then combined with the distortion record to effect negative distortion and get a distortion compen- sated mechanical record, that is, the final mechan- ical record is distorted negatively to the distor- tions ordinarily produced, and thus distortion is completely cancelled. Air-Blast Reproducer 1,829,801. Sound Reproducing Sys- tem, to Warren C. Jones ; assigned to Bell Telephone Laboratories, Inc. A disk record has means arranged in conjunc- tion therewith and in advance of the reproducer, for blasting a cooling current of air upon the Editedhy RL.BurKitt disk surface to harden it before it is acted upon by the reproducer. Stringed Speaker 1,829,909 and 1,829,910. Stringed Loud Speaker, to Chakir Midhat. The speaker includes a plurality of strings,, stretched over, and attached at one end to, a resonant body. At the other ends of the strings is freely suspended a disk. This driving unit is- coupled to the disk and thus acts to vibrate the strings. Combination Film 1,829,912. Combined Sound And View- Film And Method Of Making The Same, to Douglas G. Shearer; assigned to- Metro-Goldwyn-Mayer Corporation. The sound record and the picture film are on. two strips and are secured together along their longitudinal edges. These edges are formed in. stepped relation for interlocking, and are ce. mented together along these edges. Film Trap and Door 1,830,158. Film Trap and Film Trap- door, to Augusta Dina; assigned to the- Precision Machine Co., Inc. A film trap carries bodily a movably supported door. Means are provided for propelling the door to closed position while impact means for absorbing the closing shock are disposed in oppo- site relation to the door. 1,831,346. Compound Base For Mo- tion Picture Projection Machines, to- Augusto Dina; assigned to International Projector Corporation. A base normally adapted to rest on a floor is provided with means for tilting one of its ends^ Lamphouse Support 1.830.537. Lamp Support For Pro- jection Machines, to Louis Simon Frap- pier and Ewald Boecking; assigned to- International Projector Corporation. A rotating member is provided in connectioDi with the telescope by means of which any one of a plurality of lamps may be positioned in rela- tion to the telescope; when so positioned, only that particular lamp is energized. Detents are- provided for securing the sockets in relative rela- tion to the telescope. (See patent following.) Improvement For Same 1.830.538. Support For Light Sources, to Louis Simon Frappier and Ewald Boecking; assigned to International Pro- jector Corporation. This improvement on the preceding patent pro- vides curved shanks in each socket, these shanks^ being secured by set screws to a rotating sleeve carrying the sockets and having apertures larger than the said screw so that variable adjustment may be obtained. P. E. Cell Process 1,831,314. Photoelectric Tube, to Archie J. McM aster and Charles E. Par- son; assigned to G-M Laboratories. The cathode of the cell has an alkaline metal deposited and oxidized on it, the excess metait being expelled during oxidation- [24] PROPER SHIELDING FOR ELECTRIC CIRCUITS John G. Ferguson MEMBER OF THE TECHNICAL STAFF, BELL TELEPHONE LABORATORIES IN ITS simplest form a condenser con- sists of any two conductors sepa- rated by a dielectric. It follows, therefore, that since air is a dielectric any pair of neighboring conductors will act as a condenser, and current will flow from one to the other when a varying potential is impressed across them. In circuit design this capacity effect may be objectionable for two reasons. It makes the value of any impedance de- pendant oh its surroundings, and also the stray current through the capacity may flow into other parts of the circuit, causing objectionable interference. Such stray capacities may be eliminated either by separating the various parts of the circuit sufficiently to reduce the effect to negligible proportions, which is usually impracticable, or by introducing a shield between the conductors. Although shielding eliminates the ca- pacity that depends on position it intro- duces a capacity of its own which is of greater magnitude. This is partly be- cause the shield is larger than the con- ductor but chiefly because being between the conductors it is nearer to both. Shielding, therefore, does not offer a simple and complete solution of the prob- lem. Careful consideration must be given in each case to the effect of the capacity introduced, and a shielding scheme adopted which will give the best overall result. Elementary Principles Certain of the elementary principles involved can be illustrated by a few simple circuits. With the single impe- dance of Figure I-A, for example, there is a capacity from different parts of the conductor to other parts of the circuit and particularly to ground, as indicated by the dotted condensers. These capaci- ties affect the impedance between ter- minals, and since they vary with the location of the impedance, the value of the impedance is variable, and is known only for the location in which it is meas- ured. By placing a shield around the impe- dance and connecting it to one point of the circuit, as shown in Figure 1-B, the capacity between impedance and the shield remains the same regardless of position, and as a result the value of the impedance is also independent of posi- tion. There remains a variable capacity between the shield and ground, but this capacity is concentrated at the single point A and may be readily measured for any position and allowed for. If it is possible to ground the terminal A, all capacities that vary with position are avoided. If the impedance of Figures 1-A and B is adjustable, the capacity to the shield will differ for each setting but a calibra- tion may be made once and will hold re- gardless of the position of the impedance, since the capacities to the shield do not vary with position. The same method of shielding may be applied to any number and arrangement of impedances, pro- vided there is only one control, since for any setting the value of the capacity to the shield will always be the same. If there is more than one method of adjustment, however, that is, if two or more parts of the impedance can be o- W/WV^AA/V o ■7vy^^^^\vv- varied independently, the adjustment of one part changes the effect of the shield on the other. With two impedances in- side a single shield, as shown in Figure 1-C, the distributed capacity between CB and the shield is in parallel with the im- pedance AC through CB. If the value of CB is adjusted, therefore, the value of AC will vary because of the change in the overall impedance from CB to the shield. Types of Shielding To avoid this condition, separate shields may be placed over each impe- dance, with that over AC connected to the point A, and that over CB to the point B, as shown in Figure 1-D. With this arrangement changes in the setting of either AC or CB may be made without affecting the other, but there will exist an additional capacity — that between the shields of AC or CB, which depends on -A/VVVY\AAAA- B A o o ^yVw>A/^A- -^A/ — o — VW ^ F H T Fig. 1. — Various shielding arrangements for an impedance or a group of impedances connected in series or in parallel [25] 26 INTERNATIONAL PROJECTIONIST February 1932 position. This capacity is slightly more objectionable than capacity from shield to ground since while either A or B may be grounded, both points may not, so that there will always remain a capacity from one shield to ground which will ■vary with position. An alternative arrangement of the shields for such a circuit is shown in Figure 1-E. The variable capacity be- tween shields remains, but it is across one impedance only. If now the shield connected to A were extended to include the other, as shown in Figure 1-F, the only capacity that varies with position is that from the outer shield to ground. If the outer shield is grounded there will be no capacities that vary with position. The extent to which the capacity be- tween shields is objectionable depends on the form of the impedance between A and C. If it is a capacity, that across the shields is merely an addition to it and is not objectionable. If it is a re- sistance, however, the capacity between shields increases its phase angle, while if it is an inductance, the shield capacity increases the variation of inductance and effective resistance with frequency. The principle may be extended to include any number of variable series impedances, the efFect being to place a capacity across all but one and to enclose the whole in an outer shield. Such a system for five elements is shown in Figure 1-G. The shielding of variable parallel im- pedances is comparatively simple since each or any number may be shielded in- dividually and all the shielding con- nected to the same point. This may be reduced to the form of a single shield with partitions to separate the individual elements from one another. Figure 1-H indicates the arrangement for three ca- pacities in parallel. By a combination of these two methods it is possible to shield any combination of series or parallel impedances so that all capacities from the shielded elements to external con- ductors Avill be concentrated at junction points or terminals, one of which and only one, may be grounded. The de- termination of which terminals the vari- ous shields should be connected to, and the terminal that should be grounded, de- pends on various conditions and no gen- eral rules can be given. No General Rule With the above procedure it is pos- sible to make the impedances independ- ent both of position and of each other. It must be remembered, however, that troublesome capacities have not been eliminated. Fixed capacities have been substituted for variable ones but in gen- eral they are larger, and if the substi- tution is at too great a price in the way of an increased total capacity, the ini- PHILOSOPHIC BACKGROUND OF UNIONS Sumner H. Slichter, Ph.D. UNDOUBTEDLY the greatest objection to labor organizations on the part of management is that they interfere with efficiency. To this objection there are several answers. One is that tliere are other things which are no less important than efficiency. Among them are security and liberty. Indeed, in view of the rapid rate at which we have been increasing per capita productivity during the last hundred years and our failure to make progress in the achievement of se- curity, it is reasonable to conclude that security today is far more important than efficiency. We could well afford to exchange some of our efficiency for more security. And the same holds true for liberty. Whether or not trade unions interfere with efficiency, they are the only means by which the workman in the vast enterprises of modern industry can acquire liberty and security. They are the only way in which he can effectively bargain over whether he shall work six days a week or five, or whether he shall be paid by the piece or by the hour, over whether a change in conditions warrants a change in his piece rate. Likewise they are the only means through which the workman can acquire security, through which he can prevent the management from discharging him whenever it wishes. Liberty a Result of Security To a substantial extent, security and liberty go together, for liberty is partly a result of security. Only when men are protected against arbitrary dis- charge, dare they to express their aspirations, ideas, and grievances without dread of being heard by the foreman. Only through security do they acquire opportunity to criticize the manage- ment, to find fault with the way the plant is run, to talk freely about how they think it should be run — in other words, to express the same sort of ideas about the man- agement of the plant that free citizens are accustomed to express about the govern- ment of the country. If these things interfere with production, the answer must be that they are well worth the cost. provement may be questionable. In prac- tice it is necessary to consider each case individually for the best results. One of the most important capacities that varies with position is that between a unit and the operator's hand that may be moving the dial to adjust it. In a re- sistance box, for example, the first re- quirement, therefore, is that the whole group of units be enclosed in a shield that completely covers the top so that there will be no variable capacity be- tween the hand and the various resist- ances. If there is only this one outer shield, there will still be variable capaci- ties between resistances which will vary with the settings of the dials. Attention ! The article on page 16 is di- rected at you, Mr. Reader — written and printed solely for your benefit. No article is worth the space it accupies unless it provokes thought and inspires action. What is your estimation of and reaction to the article on page 16? Although nested shields, as shown in Figure 1-G, would eliminate these vari- able capacities, in many cases the high additional capacities they introduced would be more objectionable than the capacities between resistances, which are generally negligibly small except for high-resistance units. For most cases even the highest resistance units do not need individual shields. With adjustable inductances the size of the coils is usually much greater than with resistances, so that individual shielding is more important. Because of the difficulty of bringing the various dials through a series of successive shields, however, and of the large size of the units, three dials represents about the maximum number that can be shielded in this way. Shielding is usually simplified with condensers because they are connected in parallel. Such a connection seems as a rule to confine all stray capacities to the terminals of the condensers. It is not necessary, experience has shown, to place shields around the individual dials of mica condensers, since the capacity be- tween them is small compared to the value of their smallest unit. Because the capacity of the air condenser is smaller than that of the mica condensers, how- ever, it is enclosed in an individual shield. February 1932 INTERNATIONAL PROJECTIONIST 27 COMPLETE ALL-A.C. SYSTEM BY PACIFIC RESEARCH /^ OMBINING modern engineering practice with simplicity of design and operation, the new all-A.C. sound sys- tem developed by Pacific Research Lab- oratories of Los Angeles seems destined to win instant favor in the sound repro- duction field. This equipment, known as the P R L Type 9-AC system, was de- signed primarily for those theatres hav- ing a seating capacity up to 1,200 seats. This unit provides all the equipment necessary between the photo electric cells and the stage horns at the extremely rea- sonable price of $200, which makes this system one of the most inexpensive out- fits on the market. Numerous speaker equipments to complete the chain are available at a very moderate price and serve to keep the overall cost within the moderate budgets of most small theatres. The 9-AC system is a complete and self-contained power supply and high- gain amplifier which gives splendid re- sults in sound-on-film reproduction, and laboratory tests of the equipment have demonstrated its performance to be on a par with the best reproducing units avail- able today. The equipment, being com- paratively small, is placed between the projectors, with connections to the photo electric cells, exciter lamps, horns and the A. C. line being brought in to a marked terminal strip through knockouts provided in the sides and bottom of the cabinet. This equipment is equipped with a new type' transformer which supplies the cur- rent fo the exciter lamps without the aid of filtering, in addition, of course, to supply current for the photo electric cells. Extreme Simplicity Controls are mounted in the top and front of the cabinet, thus insuring con- venience in operation. These controls include a volume control and sound change-over switch. The extreme sim- plicity of the whole equipment makes for easy operation at all times and makes the matter of servicing, if necessary, rela- tively easy. In this connection, the manner of NOTES front the SUPPLY FIELD mounting the amplifier and associated apparatus (as shown in the accompany- ing illustration), is worthy of note. These are mounted on a steel panel which makes it possible to remove the entire assembly from the cabinet without dis- turbing the conduit connections from the cabinet to the sound heads and other ap- paratus. For quick inspection and servic- ing one need not be bothered with a maze of wires and connections, All parts are standard and interchangeable. The low price of this sound system does not reflect the quality performance of the equipment, the price being the result of modern engineering, manufac- turing and distributing facilities rather than of inferior materials or design. This statement is borne out by performance records. Special voltages may be had upon application to Pacific Research Laboratories, 1,907 Fourth Avenue, Los Angeles. VARO-FOCUS PHOTOGRAPHIC LENS BY B. & H. BELL & HOWELL has announced a new photographic lens that opens up a wide range of new possibilities and spectacular effects. The new Varo lens Pacific Research Type P R L 9-AC sound unit is set to focus on a definite position and is not focused like the ordinary lens by moving the lens unit nearer to and farther from the film. It is set normally to focus at 150 feet to infinity. Supple- mentary lenses, screwing into the front of the lens, are available for changing the focus for other distances. Smooth Changes After focusing, various elements in the lens are moved in a synchronized rela- tion, the focal length changing in smooth progression as the position of the ele- ments are shifted. Even though these elements are changed continuously, the definition is critical at all points. Shifting is by means of cams designed and cut to an extremely fine degree of accuracy. Since changing the focal length or magnification involves chang- ing the iris continuously to correspond, the iris diaphragm is also operated by a cam at the same time as the lens ele- ments. A locking arrangement and dash- pot device in the iris mechanism avoids any possible damage to the iris due to incorrect operation. A "breather" takes care of displacements of air occasioned by moving the lens elements. NEW ARC CURRENT CONTROL BY CUTLER-HAMMER A NEW automatic current controller for arc projection machines, designed to replace the usual knife switches used to control the current to the carbons of the projection machine, has been put out by Cutler-Hammer, Inc., of Milwaukee. The controller proper can be mounted with the resistor in any out-of-the-way place. Only the push-button master switch is mounted on the machine, near the projectionist. By simply pushing the "start" button of the master switch, the projectionist obtains a low current for warming carbons. Then after a definite time interval the transfer to high current for normal projection can be made by pushing the "run" button in the master switch. The definite time interval (about one second) which must expire before the projectionist can transfer from low or starting current to the high running current, assures that the carbons are suffi- ciently warm, thereby preventing sput- tering. PORTABLE FILM CLEANING MACHINE INTRODUCED 'T^ HE National Film Renovating Co. of New York has introduced a portable film cleaning machine. Wholly automatic in operation, the cleaner weighs but 22 pounds, including the motor. The device includes a casing comprising an upright box-like section, closed at the top, bot- tom, sides and back. It is entirely open at the front., A pair of doors hinged at the opposite sides of the casing section serve to fully close the front. The entire cleaning mechanism, toge- ther with the reels for the film, is en- closed in the casing. An electric motor and power transmission mechanism for operating the cleaning mechanism and 28 INTERNATIONAL PROJECTIONIST February 1932 AMPLIFIER COMPENSATOR PROJECTOR SWITCH SWITCH SWITCH AND AWPLiFiER, VOLUME CONTROL Mechanism of RCA portable 16 mm. projector for rotating the film reels are mounted upon the exterior of the casing at the back. Feet serve to support the casing upright. The machine is a compact port- able unit designed for standing upon a table or any other elevated support. 16 MM. SOUND-ON-FILM RCA EQUIPMENT ANNOUNCED as the culmination of four years of intensive development and heralded as the most advanced step in the field of sound reproduction RCA Photophone, Inc., and the RCA Victor Company have introduced a new all-AC operated 16 mm. sound-on-film motion picture projector. RCA Victor Product Manufactured by the RCA Victor Com- pany at its plant in Camden, N. J., and referred to as the RCA Photophone Junior Portable to distinguish it from the 35 mm. Senior Portable which has been on the market for more than a year, the new machine gives rather an amazing performance when its own dimensions and the dimensions of the slender thread of film used are taken into consideration. With the projector placed about 30 feet distant from the screen and the loud- speaker behind the screen, a picture about 4 feet by 6 feet in dimensions and sound of excellent quality are reproduced with remarkable fidelity. The RCA Photophone Junior Portable ;^^^=^- Showing extreme portability equipment consists of a projector-ampli- fier unit and a small loud speaker unit. The entire equipment is operated from any 110 volt, 50- or 60-cycle A. C. light- ing circuit. Specifications The projector-amplifier unit is 14V2 inches long, 13% inches high, 8% inches wide and weighs 43 pounds. The equip- ment is not removed from its Case during operation, the interior mechanism being readily accessible for such adjustments of the projector, replacement of radio- trons, lamps and photocells as may be required. During the actual presenta- tion of sound pictures, the case is closed to reduce to a minimum extraneous noise caused by the operation of the projector mechanism. The projector is equipped with an optical system which projects pictures varying in size from 22 inches wide x 16 inches high at a distance of 10 feet; to 67 inches wide x 50 inches high at a distance of 30 feet. The picture size recommended for good illu- mination is 52 inches wide x 39 inches high. This size is obtained at a projec- tion distance of 23 feet. The exciter lamp is a 4-volt, .75-am- pere, incandescent lamp and the radio- trons used in the amplifier are one UX- 868 photocell, one UY-224, one UY-227, three UX-345s, and one . UX-280. All power for the operation of the loud speaker is obtained from the projection- amplifier unit. Ample Volume The loud speaker is mounted in an in- dividual carrying case which is 19 inches long, 16 inches high, 9^ inches wide and weighs 21 pounds exclusive of film cases, film reels and film. Space is pro- vided in the case for the storage of eight film cans for 400-foot film reels. This loud speaker is of the flat baffle type with the dynamic speaker unit mounted behind the screened opening in the front of its carrying case. A sufficient volume of sound is available to meet the require- ments of rooms having a cubic content up to 10,000 feet. The 16 mm. film employed for the reproduction of sound pictures by the Junior Portable contains sprocket holes on one side only instead of both sides as are required by the 35 mm. film. When threaded into the projector, the sprocket holes are on the right side of the film. The sound track, barely discernible to normal sight, is at the left. W. E. vs. AMPLION OF A. Western Electric has obtained a per- manent injunction against the Amplion Corp. of America and. the other defen- dants in its patent infringement suit as the result of a consent decree entered in the Federal Court, Southern District of New York. The decree sustains both the validity and infringement of the W. E. patents, the Wentes and Harrison patents covering inventions used in loud speakers for talking picture reproduction. In return for the waiving of other than nominal damages by W. E., it is agreed that all infringing equipment in the de- fendant's possession shall be turned over. The waiver, however, does not restrict the rights of W. E. to bring suit against any theatre equipped with the infringing ap- paratus. [Editor's Note: The Amplion Corp. of America should not be confused with Amplion Products Corp. of New York City.'] RCA PHOTOPHONE-RCA VICTOR CONSOLIDATION RCA Photophone, Inc., which has func- tioned as a separate corporate entity heretofore, has been consolidated with the RCA Victor Corp., of Camden, N. J. This move is the latest step in the uni- fication of activities of the Radio Corpor- ation of America and its affiliated sub- sidiaries. Removal of the RCA Photophone, Inc., laboratory equipment, office furniture and all records of the company has al- ready been effected. RCA Photophone will maintain a contact office in New- York at 411 Fifth Avenue. PROTEST THEATRE TAX The LA. General Office has been de- luged with copies of communications sent by the local organizations to their Con- gressmen and United States Senators, as well as the replies received, in opposi- tion to the proposed theatre taxation as presented by Secretary of the Treasury Mellon, in a concerted effort to have this measure defeated. The theatrical indus- try as a whole is protesting against the proposed restoration of the war-time ad- mission taxes, due to the unsatisfactory condition of the industry at the present time. The tax proposed by the Ad- ministration is 10 per cent, on all ad- missions above ten cents. Urge Support Any local union who has to date neg- lected to communicate with their Con- gressman and United States Senators, as requested, are urged to immediately see to it that such detail is carried out in support of this worthy cause. February 1932 INTERNATIONAL PROJECTIONIST 29 S.M.P.E. PROJECTION COMMITTEE WORK INVALUABLE— GOLDSMITH THE work of the Projection Practice Committee of the Society of Motion Picture Engineers, when completed, will be a valuable contribution to the motion picture industry, according to Dr. A. N. Goldsmith, president of the Society, who attended a recent meeting of the com- ;mittee. "When I recall that the driver of a five hundred dollar automobile has at his command an oil guage, a speedom- (•eter, an ammeter, a radiator thermom- eter, and what not, with which to 'Feel ;the pulse and take the temperature' of the machine continuously while operat- -ing it, I look with astonishment and : sympathy at the projectionist, who is •obliged to project pictures night after night before a one-thousand-dollar-box- •office house, in a two hundred thousand ■dollar theatre, literally, as it were, in the dark, and partially ignorant of the •condition of the projector until its condi- tion becomes so bad that the effect is seen upon the screen and is heard in the sound," said Dr. Goldsmith at the meet- jng. Audience Reaction "Then it is too late — the audience has seen the effect, consciously or uncon- 'ciously, the audience carries away a feel- ing of dissatisfaction, the magnitude of which depends upon the seriousness of the circumstance, and may look else- where for better pictures and better :sound. "When the Projection Practice Com- mittee will haA>e completed its work of determining all the tolerances, clear- ances, and tensions for all moving parts •of the projector, as it has set out to do, and of determining the amount of wear to which these parts may be subjected with safety, it will have completed an invaluable piece of work. "But the final economic results of the work will have been achieved when the Committee successfully indicates the simple means to be used by the projec- tionist to check these things, and the de- sign of a cheap and simple kit of tools which' he may use to do so. The So- ciety of Motion Picture Engineers should do its best to make it easy for the pro- jectionist to determine the exact condi- tion of the projectors and to prove the occasional and timely need for replace- ment parts to the properly economical exhibitor. This means money in the ex- hibitor's pocket through better audience reaction, and also a more satisfactory and dignified position for the projectionist. "Flicker, shaking of the picture on the screen, ont-of-focus effects, poor sound reproduction, all of which can he caused by the wearing or the maladjust- ment of parts, will then be under the con- trol of the projectionist, who will be able to check and to readjust or replace the faulty parts before they are allowed to annoy the audience, irritate the theatre owner, and drive away the patrons. Selling Entertainment "For it is axiomatic that every busi- ness, to be successful, must serve the in- terests of the customer — the object of the motion picture theatre is to sell entertain- ment to its patrons, and everything that can be done to improve this product (the entertainment), will serve not only to maintain this patronage, but to increase it." In addition to the study which forms the subject of Dr. Goldsmith's remarks, the Committee is working on such prob- lems as the determination of screen brightness in relation to its effect upon the audience, and the advisability of stopping down the projector lens when projecting cartoons and other bright sub- jects, or otherwise getting the same ef- fect; and the design of suitable appa- ratus for equalizing the sound outputs of the two projectors, so that no difference in sound level will be discernable by the audience when the change-over occurs. The successful progress of the work of the Committee is due largely to the ef- forts of Messrs. Harry Rubin, Chairman, Jesse Hopkins, H. Griffin, F. H. Richard- son, P. A. McGuire, J. 0. Baker, S. Glauber, and George Edwards. Elements Necessary for Good Reproduction WHAT are some of the elements which are necessary in order to achieve the illusion of reality in a sound picture presentation? First, in speech presentation the words should be under- standable, one from another, and they should all sound like the speech of hu- man beings. There are very few persons whose voices sound exactly alike, and it is often the case that certain types of sound apparatus may render the speech of the various characters in a sound pic- ture quite intelligibly, yet with little dif- ference between the voices of the various men or women in a picture and with voice quality that no human being ever possessed. In music the distinguishing feature of natural sound reproduction is the fact that all of the instruments in a full or- chestra can be clearly distinguished one from another. In addition, there is a great width of tonal range, so that the lowest bass notes and drum beats can be heard as clearly and loudly as the highest tones of a violin. Uniform Reproduction Further and even more important is uniformity and evenness of reproduction. By this is meant equal loudness of the various tones of the musical scale. Poorly designed equipments (particularly loud- speakers ) , are frequently marked by the fact that as the music goes up or down in pitch certain tones will stand forth violently while others can scarcely be heard. This difficulty is due to what is called "resonance peaks" in the loud- speakers. In addition to the general character- istics outlined above there is a character- istic which is common to both speech and music, and that is smoothness of indi- vidual speech sounds or musical tones. By this is meant freedom from tremolos or additional fuzzy, raspy or other types of harsh noises accompanying the words or music. Complete naturalness of reproduction requires that all equipment be capable of recording and reproducing a very con- siderable percentage of all sounds which the human ear can hear from the lowest to the highest tones. The extent to which this is done is called the "frequency range" of the equipment. Notes C. M. Fowler is the new president of Chapter 7, American Projection Society, located in Los Angeles. Fowler succeeds Sidney Burton. Emil W. Lindholm is the new secretary. Officers of L. U. 640 (Nassau and Suf- folk counties, N. Y.), for the coming year are: president, Joseph Engle; vice- president, M. D. O'Brien; business man- ager, Frank Cummings; secretary, Rod- ney Titcomb; treasurer, Dave Peshkin. • Independent M. P. Operators & Service Engineers Ass'n of the U. S. A., Inc., an open shop union that claims 800 mem- bers throughout the country, now is in Minneapolis. Officers are: William H. Gage, president ; Burt Carlisle, vice-presi- dent and business manager; M. J. Gil- fillan, secretary. Thad Barrows has been re-elected president of Boston Local Union 182 for another term. Other officers elected were business agent, James F. Burke; Albert Moulton, financial secretary; Jos- eph Rosen, treasurer; Maurice Adelson, John FuUeck, and Bernard McGaffigan, directors. Barrows, who is president of Projec- tion Advisory Council, was unopposed in the L. U. 182 election. INTERNATIONAL PROJECTIONIST February 1932 1 DESIRE to compliment you on the high quality of International Projectionist. I read it from cover to cover, and although L have seen many^ magazines ostensibly for the projectionist, I have heretofore found none that even begins to compare with I. P. Almost without exception every article and item in your paper is of real value to those projectionists who are far-sighted enough to realise the possibilities in this field. I have heard many reports on I. P. from members and uniformly they agree as to its splendid practiced worth. ROBERT GARWIN, President, Cleveland Chapter, American Projection Society, INTERNATIONAL Edited by That which impresses me about I. P. is that it is so intensely practical : it is published for projectionists and not for "engineers." We who have been active in the craft for many years never suspected that one day the craft would be represented by so fine a magazine as I. P. Your editorial content and your style inevitably will be copied, but the imitators will have to step pretty fast to match your high-gear speed. W. G. WOODS, Secretary Local Union 162, Sim Francisco, Calif, I think I. P. is absolutely 100% and should be in the hands of every projec- tionist who has the interests of his craft at heart and who is anxious to be "ahead" PROJECTIONIST James J. Finn in his work. What projectionists over here think of your paper is best expressed by the enclosed orders. I. P. offers practical in- formation for the practical projectionist without any frills or furbelows. STANLEY T. PERRY, President, Kinema Projectionists' Guild, London, England, Just a note to let you know that we all think I. P. is more down-to-earth, straight-from- the-shoulder and contains more practical information and is more full of facts than all the other magazines put together. We don't want to miss a single issue. RAY WILSON, Secretary Local Union 688, McAllen, Texas. Use this blank to record your sub- scription and insure receipt of all copies. If you are already a subscriber, pass along this blank to your brother projec- tionist. 1 Year . . $2.00 2 Years . . $3.00 INTERNATIONAL PROJECTIONIST 1 West 47th St. New York, N. Y. Date 193. . Enclosed is $ for year(8) subscription to begin with issue. I Name Address j City . I Local State . February 1932 INTERNATIONAL PROJECTIONIST 31 $275 a pair WEBER SYNCROFILM SOUND EQUIPMENTS HAVE STOOD THE TEST IN AMERICA'S FINEST THEA1;RES not a bit EXPENSIVE yet such QUALITY! SYNCROFILM "B" SOUND HEAD For Simplex or Powers Compact and sturdy in construction, simple to operate, perfect in efficiency. Smooth, quiet, positive drive as- sures even tone quality without distortion. Sound heads are furnished complete and include optical systems, photo-cells, exciter lamps, adjustable motor mounting brackets, endless woven belts, grooved motor pulleys and all necessary attachments for projector. Money-Back Guarantee Easy to Install WEBER MACHINE CORP. 59 BUTTER STREET ROCHESTER, N. Y. Expon Office: 15 Laight St., N. Y. C. D. C. POWER SOURCES {Continued from page 15) article will compare these various uses and economies of many systems employed to supply this direct current. We learn from a study of electrical theory that there is only one actual iiource of direct current and that is bat- teries. Any device that has been used as a battery substitute (and most all of them have been designed from the angle of eco- nomy), do not furnish actual direct cur- rent but the next nearest equivalent — • -which is pulsating direct current, raw or filtered, or rectified alternating current, filtered or unfiltered. If the noise component measured in units of sound (which is an inherent part of all d.c. substitute devices ) , can be kept below the minimum level, de- pending upon the type of equipment used and the volume standards of sound pic- ture production, or the point where it will not be additive to the reproduction volume, such a device can be adapted as a direct current substitute. Purely a Substitute In doing so, however, we immediately reduce the standard of sound transmis- sion by the acceptance of economical tolerances. Should any of the constants required for generation, rectification, and filtering in those substitutes accidentally alter their physical or electrical status, our entire set-up becomes disrupted and reproduction is marred by commutator ripple, A.C. hum, rectifier hum, and so forth. Batteries Best So, getting down to brass tacks, if we must use direct current, there is only one kind to use and only one place to get it. If we use another kind of current as a substitute, we do it for economical rea- sons and therefore must be satisfied with the results. Such results this writer holds to be only an imitation of the best. The foregoing is also true of rectifier current for use at the arc. I should like to add that this state- ment is not primarily a criticism of Mr. Bagno's article as presented herein but rather a rebuttal of the argument that anything other than a storage battery will give us that type of current which it is admitted we must have. It might be added, whether fairly or unfairly, that Mr. Bagno's article seems to favor rec- tifiers. [Note: Additional comment regarding the foregoing presentation of data rela- tive Jo sources of power supply are in- vited— Editor.] NEW STUDIO AGREEMENT TO HOLD UNTIL 1934 A SUCCESSION of conferences, com- mencing Monday, January 11th, and terminating Friday, January 15th, re- sulted in practically the ratification of the West Coast Studio Agreement, which had expired on November 29th, 1931, and was extended to January 11th by mutual agreement. These meetings were held in the offices of the Vandeville Managers' Protective Association. 1600 Broadway. New York City, and were attended by the following representatives of the various theatrical interest: Harry Warner, of Warner Brothers Theatres, Inc.; Nicholas Schenck, of Loew, Inc.; Major L. E. Thompson, of Radio - Keith - Orpheum; Sidney Kent, of the Paramount-Publix Corporation; an official of Universal Pic- ture; Pat Casey, Chairman of the Pro- ducers' Committee, and Al Berres, Secre- tary of the Producers' Committee. The 32 INTERNATIONAL PROJECTIONIST February 1932: What does Television mean to You? JLJI. ERE is a new book that gives all the facts about this new and amazing offspring of radio. Avoiding technical terms it follows the development of television right up to date, explains principles, methods and apparatus, and weighs for you the problems, possibilities and probabilities of television as a commercial tool and a form of entertainment. Just Published TELEVISION by EDGAR H. FELIX Radio Consultant 276 pages, 5J^x8, illustrated, $2.50 HAS television arrived at last? Can present broadcasting and receiving equipment be adapted to television? Will television of the future come by air or wire? This book from beginning to end was written expressly to supply reliable answers to these and hundreds of other questions you may have asked regarding television. With many explanatory illustrations and diagrams it gives a thorough background of technical facts — then makes pHain their importance from the standpoint of the experimenter, the commercial operator, ihe broadcaster, the "listener-in." Order from INTERNATIONAL PROJECTIONIST 1 West 47th Street New York, N, Y. TELE- VISION Covers television topics such as: —lias Television really arrived ? the HOW and WHY of Television. —unsolved problems of Television, ^-possibilities of 100-line system, ——latest synchronizing methods. ^— the human eye in Television, ^— will future programs come by air or wire? ^— new developments affecting receiver design, ^—future progress of Television. 24 experts explain sound-recording and projection HERE is a book needed by every man connected with the practical side of the talking picture industry, in theatre or studio. Written by the men who taught the screen to talk it covers every phase, both technical and practical, of sound recording and reproduction. Recording Sound for Motion Pictures Published for the Academy of Motion Picture Arts and Sciences Edited by Lester Cowan 404 pages, 6x9, 229 illustrations, $5.00 Answers many questions on: — practical technique of recording — booms, blimps and microphones — recording systems — film laboratories — assembling the talking picture — reproducing systems — practice and problems of sound projection TWENTY-four sections, each written by a recognized authority and specialist in his field, present an authoritative description and ex- planation of the fundamental principles involved in recording and repro- ducing sound for motion pictures and their practical application in the studio, on location and in the theatre. Everything essential or important is covered, from the fundamental nature of sound, down to the practical aspects of volume control, theatre acoustics, and other everyday problems of sound projection. Order from INTERNATIONAL PROJECTIONIST 1 West 47th St. New York, N. Y February 1932 INTERNATIONAL PROJECTIONIST 33 affairs of the different labor organiza- tions were handled by H. C. Fechner of the International Association of Machin- ists; E. D. Beritz of the International Brotherhood of Electrical Workers ; L. P. Lindelof of the International Brother- hood of Painters, Decorators and Paper- hangers of America; A. Muir of the United Brotherhood of Carpenters and Joiners of America; Joseph N. Weber of the American Federation of Mu- sicians ; William C. Elliott of the Interna- tional Alliance of Theatrical Stage Em- ployees and Moving Picture Machine Op- erators of the United States and Canada, and Frank Carothers, Secretary of the Internationals' Committee. Several other officials of the various crafts were also in attendance, among them International Representative Walter S. Croft of the International Alliance. Minor Changes Renewal of the agreement in its en- tirety, admitting only of several minor changes affecting the Cameramen's Local organization, was obtained with the un- derstanding that all crafts will continue working on this agreement as at present in force, pending adjustment with the Cameramen. The new agreement will be in operation until January, 1934. Inasmuch as the Laboratory Tech- nicians, Local No. 683, was formed since the last Studio Agreement had been exe- cuted, additional clause was inserted, providing for their inclusion in the new agreement. No consideration or recogni- tion would be given by the Producers to making the Film Editors and Cutters parties thereto. Also an alteration occurred in the Basic Studio Agreement as a result of the withdrawal of the International Brotherhood of Painters, Decorators and Paperhangers of America when the Pro- ducers refused to recognize their four different departments. This action leaves but four remaining crafts in the Basic Agreement — the Electrical Workers, Car- penters, Musicians and the Alliance. Provision was made, however, that should the Painters desire to reconsider and again become part of the agreement, there will be no objection from any source. Locals Concerned The General Office is very grateful for the co-operation accorded them by the delegation from the West Coast in be- half of the five LA. organizations af- fected: Moving Picture Machine Opera- tors, Local No. 150; Studio Mechanics, Local No. 37; Laboratory Technicians, Local No. 683; Sound Technicians, Local No. 695, and Cameraman's Local No. 659, who very ably and efficiently handled the affairs of their particular local unions and were tireless and unceasing in their efforts to clearly and adequately present their individual situations. Final disposition of the Camerman's situation will be taken up by President William C. Elliott and First Vice-Presi- dent John P. Nick when they shortly join International Representative Walter S. Croft on the West Coast. Croft has been handling the Studio situation off and on for the past two years. NEW DEVELOPMENTS SPUR ACOUSTIC ART INSTRUMENTS for use in connec- tion with acoustic studies have been developed in the Bell Telephone Lab- oratories for use by Western Electric Co. which have aided mightily in cor- recting and providing for the proper ren- dition of sound in auditoria. Out of the studies of many auditoria have come certain definite facts concerning the ac- tion of sound waves which are of great interest and importance in the evolution of the acoustic art. In a "live" room, one with walls only slightly absorbing, the sound wave makes many trips about the room before it is completely absorbed. In a "dead" room, on the other hand, one with walls highly absorbed, the wave makes only a few Hoffmann - Soons Every known quality necessary in producing perfect projection is embodied in perfection rheostats. PERF^JlDN ^ SOLDERLESS ADJUSTABLE LUGS Heavily Construcled Will take wire sizes from No. 4 to No. 4/0 Recognized as the highest standard everywhere [ Sold by all branchc!- of the National Theatre Supply Co., Sam Kaplan, New York; Continen- tal Theatre Accessories, and by your dealer. ] The Only Union-Made Rheostat We Build Rheo- stats for Special Requi r e m e n t s . Communicate With Us Direct. There Is No Ob- ligation. R HOFFMANN - SOONS ELECTRICAL & ENGINEERING CORPORATION 387 FIRST AVE., NEW YORK HE OS TATS 34 INTERNATIONAL PROJECTIONIST February 1932 International Photographer Is a finely printed and beautifully illus- trated monthly magazine owned by the West Coast Cameramen's Union In all matters concerning the profes- sional motion picture photographers of the country it is the official organ It is designed to appeal to amateur followers of 16mm. cameras as well as to the most advanced technicians The columns of the magazine recog- nize the close relationship between the photographer and sound recorder If your news or kodak dealer does not carry the magazine on its coun- ters write for a sample copy to INTERNATIONAL PHOTOGRAPHER GEORGE BLAISDELL, Editor 1605 North Cahuenga Avenue, Hollywood, Calif. 25 cents a copy $3 the year trips before its energy is entirely ex- hausted. Each component wave element- of sound in an auditorium has a definite period of life which begins when that wave is given off by the source of sound, and ends when its intensity falls below what is known as the threshold of hear- ing. During this life period of any one sound wave, its intensity decreases in steps — falling a constant proportion with each reflection. Total Room Energy The total sound intensity in the room is the summation of the waves just sent out by the source and the various trains of waves which have been reflected and re-reflected from the walls and fixtures in the room. From the beginning of emission of sound to the first reflection, the intensity of the sound in the room is that of the direct waves; from then until the second reflection it is that of the di- rect wave train plus the contribution of the reflected waves. This building up of the intensity con- tinues until there have been so many re- flections that the intensity of the first emitted wave is negligibly small. There is a definite period, therefore, before the sound intensity' in a room reaches its full value. The source is constantly emitting new sound waves and each wave is being reflected back and forth from the walls and fixtures and. although losing part of its intensity at each reflection, is adding its remaining portion to the sound already in the room. This period of building-up is thus equal to the time required for any one wave to have been reduced, by reflection, to an intensity below the threshold of hearing, that is, to that intensity which will no longer add an audible component to the sound already in the room. It is thus the life of a single sound wave that determines the time required for the sound in a room to attain its full strength. Wave's Lif^ Span In a somewhat similar manner the life span remarks off the period between the cessation of sound emission and the ac- tual disappearance of the sound. When a source is cut off, the last emitted wave will have its full life span to live, and a certain wave will have just reached its death level. From this time on no new waves will be born, but the death rate will continue unabated until the last wave has disappeared. The life span of a sound wave (or in other words, the period for which sound persists after emission has ceased), is controlled by the power out- put of the source, by the average dis- tance between reflections, and by the fractional part of the energy absorbed on each reflection — or, as the engineer says, the "average co-efficient of absorption" of the walls or other obstructions in the room. With fixed room conditions, therefore, this period varies only with power out- put, and when the intensity produced is a million times the minimum audible in- tensity, the period is called the reverbera- tion time for that particulai: room. This term was first used by W. C. Sabine, and the value of intensity selected was tht obtained from organ pipes used for most of his work.,- - Reverberation time, however, marks merely a period durifig which the sound drops a definite amount in intensity. No information whatever is given by it as to the relation of sound intensity to time withifi^the period. Rooms in which sound decayed in quite different manners might yield the same reverberation time. Although, on that account, reverberation time is easily measured, it is of little use. Denver L. U. Election J. E. Davis was elected president of Denver, Colorado, Local Union 230 at the last meeting. Other officers named for the coming year are: James Dooley. vice-president; Larry Campbell, record- ing secretary; E. A. Roegner, financial secretary; and George Thomas, business manager. THE BOOK OF THE MONTH THE BOOK OF THE YEAR THE BOOK of the MOTION PICTURE INDUSTRY SOUND PICTURES AND TROUBLE SHOOTERS MANUAL By JAMES R. CAMERON and JOHN F. RIDER Introduction by WILLIAM F. CANAVAN (Inter. Pres. I.A.T.S.E. & M.P.M.O.) LATEST MOST COMPREHENSIVE AUTHENTIC BOOK ON THE SUBJECT PUBLISHED USED BY THE MOTION PICTURE INDUSTRY THROUGHOUT THE WORLD AS THE STANDARD AUTHORITY USE THE COUPON A COMPLETE GUIDE for TROUBLE SHOOTING U. S. DEPT. OF COMMERCE THE LEAGUE OF NATIONS (MOTION PICTURE SECTION) (CINEMATOGRAPH INSTITUTE) T-i L 1 /^ > N u ij u • ii "Mr. Cameron is one of the very limited These books (Cameron s) should be in the . r ^ l • i •» • \ x. ... number of technical writers on cinematography possession of every projectionist, theater man- really worth reading." ager and everyone interested in receiving au- "His books are of particular interest be- thentic information regarding the application cause, although essentially technical and based c J. .• •. n _>ui upon theoretic principles, they are nevertheless of sound to motion pictures. Cameron s books ",. , f t- < j . . . . within the grasp or any reader vrishing to ac- are a worth while contribution to the motion q^j^g ^ knowledge of the sound-film in all its picture industry. aspects." ENDORSED BY THE TRADE PRESS THROUGHOUT THE WORLD 7rt r^ The making and showing of Sound Motion Pictures, Sound- ^IV Kll jy On-Film and Sound-On-Disc is covered thoroughly and in an ' J ^^^^^ expert manner. The book is written so that the subject mat- m ^^^^^ ter is easily understood. Explains in detail the construction, M J l||l 1 00 operation and care of sound recording and reproducing equip- ]g X W ment. Every known trouble to sound equipment is listed in this book with full simple directions for its cure and explana- tion as to its cause. A Complete List of Our Motion Picture Books Sent on Request. YOU_WANT_THE_BEST— THEN ORDER A CAMERON BOOK CAMERON PUBLISHING CO., WOODMONT, CONN., U. S. A. GENTLEMEN: HERE IS MY SEVEN-FIFTY. SEND ME A COPY OF SOUND PICTURES. NAME ADDRESS There's a Visi+ron Cell for every make and model of sound-on-film equipment. Install Visitrons and forget thenn! Save worry, expense and trouble and insure the most Brilliant and satisfying Sound Reproduction you ever had. If you've never tried and compared a Visitron Photoelectric Cell by testing it In your equipment, you can't realize what a big difference a good cell makes. Try one Today, and two years from now you'll still be glad you switched to Visitrons INSIST ON Manufactured by G-M LABORATORIES, INC 1737 Belmont Avenue Chicago, III ISITRON PHOTOELECTRIC CELLS Order Them BY NAME from NATIONAL THEATRE SUPPLY COMPANY s^» — ruh'\* ^ ^^jl-k^aMX^, . ROJECTIONISl £c//fed by James J Finn Vol. 2, No. 1 March, 1932 A magazine devoted to better visual and sound 25c. a CO] $2.00 a ye For better quality picture and sound reproduction Lightweight — yet sturdy, rigid and durable The Projection Reel Designed by a Projectionist for Projectionists i\ O seams, no brazing and no welding to break open or come apart when rewinding or while in the projector. Made of a special aluminum alloy which results in a lightweight yet sturdy and rigid reel. No rough edges to cut the fingers or damage the film. The True Reel for Projection Sold by All Leading Dealers PRICES: 15 in. reel with 5 in. hub $3.00 each 11 in. reel with 5 in. hub $2.50 each Manufactured by W. & W. Specialty Co. 159 West 21st St. New York, N. Y. March 1932 INTERNATIONAL PROJECTIONIST Strong Electric Change-overs FOR REAR SHUTTER MOUNTING The "Super" For ntaunting on a rear-shutter Simplex or at the port opening for use with any projector Specifications: Cast aluminum housing. Black crakle finish. Aluminum blades. Asbestos cover- ing. 110-volt coils (specify whether A. C. or D. C. wanted). Patented automatic current cut-off which cuts the current off the coils auto- matically. You Can't Burn Out the Coils Furnished with 5-foot lead wires and conduit. A space is provided to install op- tical glass when mounted at the port opening. $40 each FOR FRONT WALL MOUNTING The "Special" A new member of the famous Strong family of high-grade elec- trical projection equipment Exactly the same in every way as The "Super" except that it does not in- clude the automatic current cut-off feature. The greatest value in an electric change-over available today. All orders should specify whether for rear shutter or port hole mounting and whether A. C. or D. C. coils are desired. 130 each The name "Strong" on a change-over has stood for precision projection work for more than 15 years. There is no substi- tute for a Strong Change-over. Sold and Serviced by Alt Leading Dealers. Manufactured by ESSANNAY ELECTRIC MFG. CO. 2809 West Van Biiren St. Chicago, niinois INTERNATIONAL FKOJECTIONIST March 1932 ANPLION OCTOPHASE SPEAKERS AUDIBILITY - INTELLIGIBILITY - DURABILITY EFFICIENCY and FREQUENCY RANGE a^ Choose the AMPLION OCTOPHASE It is so much finer, yet costs so little more AMPLION OCTOPHASE GIANT DYNAMIC AIR COLUMN UNIT Weight 15 lbs. Height 5% in. Diameter 5% in. Field Coil Resistance 5 ohms. Field Coil Supply 6 volts D. C. Field Current Consumption 1.2 amperes. Voice Coil impedance 16 ohms. Maximum Capacity 25 watts. Permanent Capacity 6 watts. Shipping Weight 21 lbs. Shipping Dimensions 12x12x12 in. This unit is also supplied with 1500 ohm field coil. Field Supply 110 volts D. C. Field Current Con- sumption 75 milliamperes. CONSTRUCTION In this unit, the area over a scientifically domed dia- phragm encased in a scienti- fically shaped air chamber is divided into eight divisions. The centers of gravity of each of these divisions are exactly equi-distant from the throat of the unit, and since all operate under identical pressures, the sound impulses from each di- vision reach the throat of the horn in perfectly timed syn- chronism with the arrival of sound impulses from all other divisions. From these eight divisions this reproducer de- rives its name — OCTOPHASE. AMPLION NINE-FOOT THEATRE HORN JW-9 The JW-9 Horn is especially designed for theatre and indoor use. No horn of such great clarity and wide frequency range has ever been concentrated into so small a space. It covers the full speech range perfectly pre- venting over resonance and muffling on base notes. As a reproducer of music, it possesses a brilliancy impossible of attainment in horns made of soft materials. Its nine foot air column and wide bell, assure excellent performance on the low notes. List Price $95.00 Air Column 108" Bell 34" X 26" Bell Area 720 sq. inches Weight 33 lbs. Shipping Wgt. 70 lbs. Shipping Dimensions 38"x33%"x39" Angle of Spread measured at lip of bell 36° Height 42" Width 34" Depth 37" It is those overtones from 5,000 to 8,000 cycles which give character to speech. Can you afford to nullify your entire equipment by employing speakers which cannot reproduce these frequencies? Write for folder describing the OCTOPHASE unit and complete line of AMPLION exponential weatherproof horns AMPLION PRODUCTS CORP. 38 West 21st St. New York, N. Y. March 1932 INTERNATIONAL PROJECTIONIST Edited by James /• Finn Volume II MARCH 1932 Number 1 Monthly Chat 5 Fundamentals of Testing Elec- tric Circuits — III 7 A. C. SCHROEDER Relative Foot-Candles 9 Uniform Aperture Practice Set by Academy 10 Screen Image Table Figured on Basis of New Aperture 12 A Break-Down of Service Dollar, ERPI's Reply to Critics 13 Continuous Projection by Optical Compensation 14 H. ROBICZEK Comparative Worth of D.C. Power Sources (Addenda) 16 Light and Lenses — II Victor A. Welman 18 An Open Letter to James J. Finn 21 Thad C. Barrows Common Sense and the Common Cold 22 Leverett D. Bristol, M.D. Sound Projection Facilities in the Modern Theatre 23 D. M. Cole News and Views 24 Alliance Items 29 Notes from the Supply Field 31 "Soft" and "Hard" Lighting With Supersensitive Panchromatic Film 33 James J. Finn Motion Pictuj-e Theatres in the United States 34 Miscellaneous Items News Notes Technical Hints Published Monthly by JAMES J. FINN PUBLISHING CORP. 1 WEST 47th STREET, NEW YORK, N. Y. West Coast Representative Hallett E. Cole, 846 South Broadway, Los Angeles, Calif. ('Phone: Tucker 6428) Yearly Subscription: United States and possessions, $2 (two years, $3) ; foreign countries, {2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Entered as second-class matter February 8, 1932, at the Post Office at New York, N. Y. under the act of March 3, 1879. Entire contents copyrighted 1932 by James J. Finn Publishing Corp. International Projectionist is not responsible for personal opinions appearing in signed articles in its columns. MONTHLY CHAT BY withholding the announcement of its new recording and reproducing system Western Electric Company has remained steadfast to that unwritten rule of the company which is to perfect a de- vice first and ballyhoo it afterward. Of course, our reputation as a forecaster suffered as a result of this decision on the part of W. E., as we had promised our readers full details of the new system in tills issue. "VrOW that the matter of uniform i^ aperture procedure for both pro- duction and projection has been settled, emphasis should be placed on the neces- sity for strict adherence to the recom- mended aperture height of .600". Vari- ance from this figure simply means that all the hard work done on this project will have gone for naught— for with the studios utilizing the full area for com- position, the choice of adhering or not to the full height lies not with the pro- jectionist. Just another usurpation of our powers over the cinema welfare of the matinee idols. TT OW many projectionists, taking -■-■- their cues from the item relative to lower insurance rates which appeared in our February issue, have asked their insurance companies for a reduction in rates? The facts with which to buttress your argument were included in this item; and if you haven't yet taken ad- vantage of this situation, do so promptly. • . . Don't mention it. Just another one of our little services. SAMUEL BAGNO'S article, "Compar- ative Worth of D.C. Power Sources," which appeared last month proved defi- nitely how little time most manufacturers of. power supply devices spend at their plants. The number of "out-of-towns" which were received in reply to our re- quests for comment on this article sur- passed all previous high marks. On occa- sion we find it convenient to be "out of town," but never when something is said, or written, or done to reflect unfavorably upon our product. And particularly happy are we to be in town when an offer to run our comment verbatim is made. The inevitable ray of sunshine makes; its appearance in this case: we are over- flowing with happiness to be able to re- port that the proper parties were avail- able at Roth Brothers & Co., 1,400 West Adams St., Chicago, and at Electric Spe- cialty Co., Stamford, Conn. — both houses being the manufacturers of very fine products for projection room use. \Vliat yowr ERPI SERVICE dollar buys •••••• These facts show how each ERPI Service dollar protects the exhibitor m. 54.1% for the inspection service that prevents trouble — rendered by 600 men traveling 5,720,000 miles a year — to maintain highest standard of tonal quality. MM 13% for emergency and appoint- ment calls which would be greater except for the preventive inspection ;service. MMM 13% for maintenance of 35 branch offices, 173 other service points and $750,000 stock of spare parts which make possible immediate emer- gency repairs, quick replacements. MV 4.6% for replacements, repairs and improvements made at ERPI cost and for maintenance of Bureau which reduced repair costs 46% in 1931— saving exhibitors over $750,000! V 4.3% for general administration and engineering which make possible efficient nation-wide service and uni- form quality operation. VM 11% for protection against fire loss — assuring complete replace- ment immediately without cost to exhibitor. 5 years of erpi service experience made this economic dollar division possible Experience with more than 8000 thea- tres proved to us that further reducing the number of preventive calls means increased emergency and appointment calls! CL To reduce branch points and stocks would endanger maintenance of service — which would prove costly to the exhibitor. CL ERPI's protection against fire loss by immediate replace- ment without loss of time is an econ- omy of ERPI service, d. All economies made possible by five years of devel- oping the present efficiency of ERPI Service have been reflected in repeated and voluntary adjustments of the ser- vice charge. Westeti SOD N D lectric Rate of ERPI Service charge reduction 1928 1929 1930 1931 SYSTEM Northern Electric in Canada Distributed by Electrical Research Products fttc, 250 West 57th Street, New York These ERPI economies have resulted in savings of more than $7,000,000 yearly to exhibitors — without impairing qual- ity and performance. m 1.9 \»'- INTERNATIONAL PROJECTIONIST VOLUME II NUMBER 1 MARCH 1932 FUNDAMENTALS OF TESTING ELECTRIC CIRCUITS A. C. Schroeder MEMBER I. A. LOCAL UNION ISO, LOS ANGELES, CALIF. Ill IN the last article we discussed the testing of a line and a fuse block very thoroughly, using a 110-volt lamp. If the line had been 550 instead of 110, it would have burned out the lamp the first time it was put across the circuit. Had we used a 12-volt lamp on the 110-volt line, the result would have been the same. Using a 110-volt lamp on a 12-volt line would give no results, the voltage not being high enough to force sufficient current through the light to give an indication. When testing a 110- volt circuit with a 220-volt lamp the re- sult is that the lamp glows dimly, but in most cases this is O.K. if the fact that we are using a lamp designed to be worked on a higher voltage is kept in mind. We now realize that testing apparatus must be suitable to the circuit to be tested: different circuits require differ- ent apparatus. Often the testing device can be adapted to the circuit. An ex- ample of this is the test lamp having two sockets and two 110-volt lamps. The lamps are in series and form the equiv- alent of a 220-volt lamp. Figure 1 shows such a tester. With it we can test both 110- and 220-volt circuits. Naturally, the lamps will not burn to full brilliancy on 110 volts. Sometimes a lead is brought out be- tween the lamps so that it can be used with one of the outside leads when test- ing 110 volts. Only one lamp lights when they are used in this manner, and it burns brightly only if the voltage is normal. Other Methods Let us leave the test lamp for the time being and take up other methods of testing. The voltmeter as a test instru- ment has certain advantages and certain disadvantages. The chief disadvantages are the delicacy of a good meter and the cost if it is ruined. Replacing a burned-out test lamp is a matter of thirty or forty cents. The cost of the average meter will run from five dollars up. It is true that meters can be obtained for about a dollar, and sometimes less, but these are not used a great deal and then only for testing battery voltages. A DC meter can be used only on DC. Some DC meters are now supplied with a copper-oxide rectifier, allowing them to be used on AC, but it is then con- sidered to be an AC meter. Most of the AC meters can be used on DC as well as on AC, although they usually are not as accurate in such a case as the DC meter. On some types of DC circuits the AC meter cannot be used at all, even though the same meter can be used on other DC circuits. Some of the advantages in using a volt- meter are that it usually shows nearly the exact voltage present. On low resist- ance circuits — such as power lines, bat- tery circuits, etc. — any ordinary meter [7] will show the voltage; but when testing high resistance circuits found in ampli- fier and power supply devices the or- dinary meter will show only a fraction of the voltage that is normally present. The reason for this is that all meters require a flow of current through the instrument in order to give an indica- tion; they are devices that consume power, and that power must be supplied by the circuit under test. If the circuit we are testing has a com- paratively great amount of resistance, there will be a large drop in voltage across it due to the current drawn by the meter. Usually there already is a cur- rent flowing: it may be the current taken by the plate of an amplifier tube. The purpose of the test might be to determine the voltage at the plate of the tube under working conditions. The current taken by the plate causes a drop in voltage across th'e resistance, and when the addi- Figure 1 INTERNATIONAL PROJECTIONIST March 1932 TO NEXT TUBE IOC^OOO?OHNS NEG. B . ._PQL..EL Figure 2 tional current taken by the meter flows through the circuit, it may upset the normal conditions to such an extent that a reading on the meter may be next to meaningless. When it is only desired to know if plate voltage is present at the tube, this indication is sufficient. The Circuit The full lines in Figure 2 show the plate circuit of a tube, and the dotted lines show how the voltmeter is hooked- in. Starting at the arrow marked "Pos. B," we see that the current must go up through the 100,000-ohm resistance, over to the plate of the tube, through the tube and down the wire to the arrow marked "Neg. B"; from here the circuit is completed through whatever the source of B potential happens to be. Notice that the tube and the resistance are in series: all current flowing through the resistance must also flow through the tube. The lead going to the next tube does not enter into this, since it does not carry DC. A condenser is placed in the line to isolate this circuit from the fol- lowing tube. Now consider the meter. It is con- nected from the plate to the filament of the tube, and the meter and the tube are connected in parallel. Any current drawn by the meter must be an addi- tional current coming through the resist- ance. In order to see why certain meters can be used and others cannot, let us analyze the conditions of this hook-up before and after the meter is connected. Resistance and Voltage First we re-draw Figure 2 so as to get it into a shape in which it will be easier to visualize what is happening. This new form is shown in Figure 3. Electrically it is the same as Figure 2, with the ex- ception that the meter has been left out. The plate to filament resistance of the tube is represented by a zig-zag line marked "10,000 ohms." This is the value that some types of tubes used in this position have, although it may be varied by changing the voltages applied to the tube. When the grid of the tube is not excited by a signal, the tube acts the same as would a simple resistance, if placed in that position. v; The total resistance from "Pos. B" to "Neg. B" is 100,000 plus 10,000, or 110,- 000 ohms. The voltage from "Pos. B" to "Neg. B" is 130. Applying ohms-law we find that there will be a current of .00118 amps., which is equal to 1.18 mils. A sensitive milliammeter would show this and make it unnecessary to work out the mathematics. We are now ready to find the drop in voltage across the tube. Multiplying the plate resistance by the current (10,000 times .00118), gives us 11.8, the effective voltage at the plate. This is the voltage a meter would show if we could get one that did not draw any current. Figure 4 shows the condition of the circuit after the meter has been added. The resistance marked 3,000 ohms rep- resents the meter. One type of meter used a great deal in projection rooms has a resistance quite close to that value. Comparing Figure 4 with Figure 2 we see that they are the same, excepting that we have used the symbol for resist- ance instead of drawing in the tube and the meter. Current coming from "Pos. B" flows through the 100,000 resistance. From the point A there are two paths that it can take: either through the 10,000-ohm resistance, which is the plate to filament resistance of the tube, or through the 3,000-ohm resistance, which is the meter — the two resistances being in parallel. Calculating Resistance To find the total resistance in the cir- cuit we must first see what the resistance is from A to B. This is found by divid- ing the product of the resistances by their sum. 3,000 times 10,000 equals 30,000,000. The sum of these resistances equals 13,000. Dividing 30,000,000 by 13,000 gives us 2,308, or 2,300 ohms in round numbers. Using ohms-law again, we have the voltage, 130, divided by the total resistance, 102,300, giving us .00127, the answer being in amperes. Multiplying by 1,000 changes it to milli- amperes, equaling 1.27 mils. (Mils, is used in place of the longer word, mil- liamperes.) Knowing the value of the current we can find the voltage at the plate. Multi- plying the total resistance from A to B by the total current flowing, 2,300 times .00127, which equals 2.9 plus, we get NEG. B NE6. 8 10,000 OHMS TO NEXT tube: 100,000 OHMS 3,000 OHMS R5 10,000 OHMS TO NEXT TUBE 100,000 OHMS Rl + POS. B Figure 4 POS. 8 Figure 3 the voltage at the plate when the meter is hooked on as shown. Bear in mind that the meter does not show a wrong value of voltage. It indi- cates the actual voltage present when it is connected across the circuit; but when it is hooked-in it changes the volt- age, the conditions not being the same as they were before the meter was used. Notice that the resistance in ohms was multiplied by the current in amperes, which is .00127. Had the figure 1.27 been used, which is the number of mils, the result would have been incorrect. Ohms-law states that the resistance mul- tiplied by the current equals the voltage — but the units to be used are the ohm, ampere, and the volt. If the current is expressed in mils., it must first be changed to amperes by dividing it by 1,000. Of course, the same thing is ac- complished if mils, are used and the answer then divided by 1,000. However, if we are not familiar with this sort of work, confusion might result, and it will probably be better if we use the first method, changing mils, to amperes and then multiplying. By using mathematics we found that the voltage at the plate of the tube is very close to 11.8. We then found that the voltage dropped to about 2.9 when the meter was applied. Needless to say, a meter that shows a reading of 2.9 when the voltage in the circuit is normally 11.8 is not of very much use. It shows the circuit to be continuous, but that is all. An open grid circuit, a defective tube, shorted condensers or resistances may often cause the voltage at the plate to actually be 2 or 3 volts, but the meter we have under discussion will not give an indication that can be depended upon to show such conditions. Meter Characteristics This meter has a resistance about one- third that of the tube. If we used a meter having a very much higher re- sistance than the tube, it will not affect the result nearly as much as the low re- sistance meter. Meters used for this sort of work are very sensitive and have a resistance of 1,000 ohms per volt. If the meter has a full-scale reading of 100 volts, its resistance will be 100,000 ohms. Let us hook such a meter into the cir- cuit shown in Figure 4 and then see March 1932 INTERNATIONAL PROJECTIONIST Table A Without meter With 3,000 ohm meter With 100,000 ohm meter Total Resistance From A to B Total Current Voltage at Plate 10,000 ohms 1.18 mils 11.8 volts 2,300 ohms 1.27 mils 2.9 volts 9,090 ohms 1.19 mils 10.8 volts what are the results. Figure 4 can still represent our hook-up, if we keep the fact in mind that R3 is now 100,000 ohms. Finding the total resistance from A to B, the product of R2 and i?3 is 1,000,000,000. Their sum is 110,000. Dividing the former by the latter gives us a fraction more than 9,090.9 as the number of ohms when these two resist- ances are connected in parallel. We drop the decimal and use the number 9,090. As far as practical results are concerned this could be changed to 9,000, and this is what ordinarily would be done, as the result would be suffi- ciently close. This would also account for small discrepancies in results at times, but these may be overlooked. The entire resistance in the circuit from "Pos. B" to "Neg. B" is now 100,- 000 plus 9,090, or 109,090 ohms. Divid- ing the voltage, 130, by this figure re- sults in .00119, or 1.19 mils. 9,090 times .00119 equals 10.8, the voltage at the plate when we use the high resistance meter. The voltage with no meter in the circuit was 11.8, a difference of 1 volt, or about 9 per cent, which is close enough. We make up a table using these val- ues and we see at a glance what takes place when the different meters are used (Table A). - Notice the small differences in values in columns 1 and 3, as contrasted with the comparatively large differences in columns 1 and 2 and also in columns 2 and 3. In testing for voltage at the plate of a tube in a transformer-coupled amplifier the high resistance meter would read very nearly the normal voltage, since the resistance of the transformer prim- ary is only a few thousand ohms and often it is less than one thousand. Under such conditions the plate voltage will be about 118 when the voltage of the B- supply is 130. Our high resistance meter would read 116, but it only has a scale running up to 100 volts, so we must use a meter having a range of 250 or 500 volts. Either of these meters will read even closer to 118 volts than the meter with the 100-volt scale. Notice that the meter reading will be less than 2 per cent off. The foregoing shows how important it is to use the proper type of testing de- vice. The low resistance meter and the test lamp were O.K. for the line we were testing in Article II, but they are alto- gether inadequate for testing high resist- ance circuits. The low resistance meter gave a small indication at the plate but the test lamp would give no indication whatever. The high resistance meters are O.K. for testing low resistance cir- cuits, providing we use one having the proper range. The 100-volt meter would not do to test a 110-volt line, nor would it do for testing a 2-volt line. If a meter is wanted only for testing low resistance circuits it would be needless expense to purchase a meter of the more sensitive type. Relative Foot-Candles IT is possible to analyze precisely the several fundamental characteristics of vision and, from these data, to deter- mine the relative foot-candles required for equality of visual difficulty in various situations. When this method of analysis is applied to the average lighting in- stallation the inadequacy of the lighting in many instances is conspicuous. There are many factors involved in seeing, but the following are funda- mental: Size of object expressed in minutes of visual angle subtended at the eye by the smallest detail to be seen; contrast between object and its back- ground— definable as the ratio of bright- ness difference (between object and background), to the brightness of the background and designated as per cent contrast; brightness level resulting from foot-candles and reflection factor; time of exposure of retina to the image of the object. The relationship between these four factors has been quantitatively deter- mined, thus enabling the lighting special- ist to make accurate comparisons between practical lighting situations. A few examples are presented herewith to illustrate the application of this analy- sis to lighting problems. Several situa- tions differing in size, contrast and time allowed for seeing were assumed and the foot-candles required in each case were obtained from the relationship of the four fundamental factors. The foot-candles given (table), repre- sent absolute values for threshold seeing, at which the object is seen with 50 per cent certainty. Such visibility is, of course, inadequate for the work-world but it is a condition at which exact meas- urement on seeing is possible. In light- ing practice, the foot-candles of the table become relative foot-candles and form the basis for a scientific distribution of light to the various visual tasks in pro- portion to their difficulty. — M. Luckiesh in Electrical World, January 9, 1932. Special Sound Reinforcing Equipment by ERPI An interesting example of how special equipment for sound amplification and transmission can be arranged in connec- tion with talking picture equipment was offered recently when the Audubon The- atr. New York, was confronted with the necessity of reinforcing a crooning spe- cialty act to satisfactorily penetrate the entire auditorium. The problem, re- ferred to the Special Projects Depart- ment of ERPI was solved by the installa- tion of a special P.A. attachment con- sisting of two microphones, a microphone control panel and two loud speakers to work in conjunction with the theatre's sound system. The Hook-Up The microphones were equipped with outlets and plugging facilities to allow placement at any desired stage location. The control panel was put in the projec- tion room near one of the spot light po- sitions. It provided means of controlling the amplification and of associating either of the microphones with the main system. The horns were located so as to project the artist's voice beyond normal range and so that patrons throughout the house could hear equally well. With this equipment the theatre was able to stage a take-off of a radio broadcast specialty number. Such special jobs can be executed at any time in connection with existing W. E. Sound System installations. Different Situations — Equal Visual Difficulty Size of Object Contrast with Time Allowed Foot-Candles (in Minutes in Background for Seeing for Threshold Visual Angle) (Per Cent) (Seconds) Seeing 0.8 50 0.17 100 1.5 50 0.17 1 1.4 10 0.17 100 3.0 10 0.30 1 10.0 2 0.30 00 UNIFORM APERTURE PRACTICE SET BY ACADEMY THE major motion picture studios and theatre circuits have adopted a uniform practice governing the image area on 35 mm. film for photog- raphy and projection which will result in an important improvement in photo- graphic quality, according to an an- nouncement by the Academy of Motion Picture Arts and Sciences. This com- pletes one of the final equipment changes in the transition from silent to sound pic- tures. Companies which 'are putting the Academy specifications into effect for forthcoming productions include: Colum- bia, Educational-Metropolitan, Fox. flal Roach, Metro - Goldwyn - Mayer, Para- mount, RKO-Radio, United Artists, Uni- versal, and Warner Brothers-First Na- tional. Studio camera apertures have been ad- justed to photograph an image .868" by .631" on the negative, with center line .7445" from the control edge, to be corre- lated to theatre projector apertures .600" X .825", with center line .7380" from the control edge, the difference being neces- sary allowances for shrinkage and me- chanical tolerances. Instructions Ready Soon Specifications and instructions for adapting apertures, lenses, and screen masks will be distributed to the projec- Fig. 1 — Academy recom- mended camera aperture New Aperture Specifications following specifications are the height of this aperture. Screen masks should be adjusted for a mini- mum overlap on the screen, as ade- quate tolerances for shrinkage and weave have been made in the specified- aperture. Photographic Image Adaptation of camera and other equipment to an aperture of .631" x .868", having its center line .7445" The recommended for studio and theatre uniform aperture practice to go into effect for new productions now being photographed : Projection Apertures Upon receiving product with the new frame size, theatres should adjust their projector apertures to dimensions of .600" X .825", the center line to be .738" from the guiding edge of the film. Other dimensions are shown in Figure 2. In no case should any theatre reduce from the guiding edge of the film. Other dimensions are to be as indicated in Figure 1. When the area reserved for the sound track is not used it is to tionists of all theatres in the United States during the next few weeks. The uniform practice will apply to all types of motion pictures made for exhibi- tion in theatres and will supplant the dif- ferent image areas used for disc prints, sound track prints and silent versions. It is expected to settle difficulties which have vexed studios and theatres since the introduction of talking pictures and to end the wide variation in projector aper- tures for which studios have had to pro- vide in photography. Principle advantages of the uniform practice will be that when equipment is adjusted to the specifications, movable lens mounts, sliding aperture plates and other adaptive devices may be dispensed with in theatres ; the likelihood of cutting off heads and feet of characters on the screen will be reduced; and both studio and theatres will be assured that the full height of the photographed image will be transferred to the screen. Increased efficiency in photographic operations on the studio set will also be made possible through the matting out of wasted film area which it has been necessary to pho- tograph to accommodate variation in the- atre apertures. Approximate 3 ;c 4 Size Projection of the picture image by the new specifications will result in screen proportions of approximately three by four in theatres with medium projection angles. The screen will appear slightly Fig. 2 — Academy recom- mended projection aperture ■iOF PRQJtrCTOH. XPE-B.-tUg.Er 02.8" L-_i =^ •738" ■SZS" .26,8" OIS" Nott-ublTto uiNfe SHOWS vaojecTap. ATE.«.-n)«.& [10] March 1932 INTERNATIONAL PROJECTIONIST 11 wider when the picture is projected from a low angle and slightly taller in those theatres with steep projection angles. The present agreement among the com- panies to adopt a uniform practice has developed from research, surveys and conferences between representatives of studios and theatres during the past ten months, under the sponsorship of the Academy Producers-Technicians Commit- tee. For the past two years studios have been composing sound pictures according to temporary recommendations issued by the Academy until theatre projection conditions should become sufficiently stabilized to warrant establishment of more permanent specifications. The revised specifications represent the best adjustment between photographic and projection requirements upon which it has been possible to secure general agreement between the studios and the- atre circuits. Previous Practice The project originally started with the studios in an effort to get away from mul- tiple composition and photography of nearly a hundred mil. wasted area on the film. Multiple composition with lines on the camera ground glass have been ex- pensive and inconvenient but necessary for the past two years for reasons given in detail in previous Academy Reports. As the percentage of disc release has been growing less, the Academy was au- thorized some months ago to investigate the problem and improve the situation. It was found that the only solution would be to correlate camera and projector apertures. A canvass was taken of studios to see if a majority favored such a step. Tentative specifications and the plan of procedure were presented in Re- port No. 24 dated October 10, 1931. The studios unanimously approved and the Academy took the next step, which was to present the proposal to the theatre cir- cuit and release organizations. The ten- tative specifications were on the basis of the largest 3x4 proportion in the cam- era but did not consider any correction for angle of projection. During consideration of the aperture proposal the theatre circuit representa- tives reached a definite basis for correc- tion for angle of projection. This basis was eighteen degrees. To get a three by •four picture at this angle a projection aperture of .590" x .825" was determined upon. Area vs. Proportion A series of conferences was held by studio technicians in Hollywood and the- atre technicians in New York, and views were exchanged. At the request of the studios the theatres made a concession in proportion for the sake of area and agreed to an alternative proposal made A Valuable Technical Accomplishment FINAL action by the Academy on camera and projector aperture dimen- sions, as reported in the accompanying article, would seem to write "finis" to this highly important and, heretofore, very troublesome matter of screen area and proportion. The Academy has approved a camera aperture adjusted to photograph an image .868" x .631" on the negative to be correlated to a theatre projection aperture of .600" x .825", which will result in a screen image of approximately 3x4 proportion in those theatres having a projection angle of 18°, which has been fixed as "aver- age." Several questions stemming out of these recommendations remain to be answered. First there is the question as to whether 18° really is "aver- age," what with many Class A theatres running up to 25° and even beyond in some instances. The answer is that investigation has definitely proven that 18°, while not wholly satisfactory to those theatres with steep pro- jection angles, is the best average figure for all theatres. Any considera- tion of standards must provide for the field as a whole, thus common sense dictates the answer to this question. The next most important question has to do with the necessity for reconciling the Academy figures with the .590" x .825" dimensions as formally approved by the S.M.P.E. through its Standards Committee. While no announcement bearing on this point has yet been made by the S.M.P.E., International Projectionist is reliably informed that the Standards Committee will give its approval to the Academy recommenda- tion of .600". In any event, the difference is so small as to be negligible. With a 16-foot screen picture the difference amounts to slightly more than 3 inches, and it is evident that this will not be noticeable. The S.M.P.E. figures will give exactly a 3 x 4 proportional screen image on the basis of an 18° projection angle. The Academy figure of .600" appears to be eminently fair, and particularly so when it is recalled that it withdrew its first request for .615" when it became apparent that Class A theatres would be penalized by its adoption. In those houses having a projection angle of 25° or thereabouts it will be necessary to still further reduce the aperture to about .580". One thing established by the investigation incident to this uniform aperture activity is the fact that a majority of the Class A theatres, which are among the finest in the field and are the most important money pro- ducers, have steep projection angles. So much for all this talk about pro- jection-on-the-level. Builders still continue to think of projection, the heart of the theatre, after everything else has been decided upon. It will be noted in the accompanying drawings (Figs. 1 and 2), that the aperture is round-cornered, a type preferred by many. Provision has been made, however, for filing of the aperture plate so that a square aperture and a resultant square screen picture may be had. Now that the dimensions have been decided upon, the next important step is the maintenance of the practice in the theatre so that the studios may safely utilize the full area available for dramatic action. Arrange- ments are now being made to supply all projectionists with full particu- lars on the new aperture, so that any possibility of error may be avoided. Pictures made on the basis of the new dimensions are already in work; but no theatre changes should be made until official notification is re- ceived from the exchanges. The establishment of this new aperture practice fully demonstrated the wisdom of furthering a closer relationship between the studio and theatre technicians with a view to effecting greater improvements in both branches. It was inevitable that each branch should seek that which was of greater advantage to itself, and the differences of opinion which de- veloped were to be expected. In this, as in all things, a willingness to compromise brought results. Many men worked many hours on this uniform aperture job, and a lack of space prevents our listing the names of all those who contributed to the task. Suffice it to say that both the production and exhibition branches of the industry benefited through superb representation by men who proved themselves commendably jealous of high quality work in their respective fields. j^j^^.^ j_ ^i^,^. Showing Size of Screen Images at Different Distances with PROJECTION TABLE : Lenses of Different Focal Length Size of Picture Aperture: 0.825 " x 0.600" B.7. In. Uo ft. 50 ft. 60 ft. 70 ft. do ft. 90 ft. 100 ft. 110 ft. 120 ft. 130 ft. lUO ft. 190 ft. 160 ft. 170 ft. 180 ft. 190 ft. ?00 ft. 2.00" 16. »^ 11.9 20.5 ih.s 2^.6 17.9 28.6 20.9 32.9 23.9 37.0 26.9 »H.l 29.9 •V5.3 32.9 2.25" l»^.6 10.6 IS. 3 13.3 22.0 16.0 25.6 ie.6 29.2 21.2 32.9 23.9 36.6 26.6 U0.2 29.2 »*3.9 31.9 3U.6 2.5.0" 13.1 9.6 16.1* 11.9 \u 23.0 16.8 26.3 19.1 29.6 21.5 32.9 23.9 36.2 26.3 39.5 28.7 «+2.8 31.1 U5.6 33.5 2.75'' 12.0 8.7 15.0 10.9 17.9 13.0 20.9 15.2 23.9 26.9 19.6 29.9 21.8 32.9 23.9 36.0 26.1 39.0 28.3 h?.0 30.5 "^5.0 32.7 M.l 31^.9 3.00" 10.9 g.O 13.7 10.0 16. U 11.9 19.2 it.o 22.0 16.0 2I1.6 17.9 27. '^ 20.0 ■^0.2 22.0 ■<2.9 23.9 35.7 2«S.9 38. U 27.9 Ul.i 29.9 U6.7 -h.O 3.25" 10.1 7.3 12.7 9.2 15.? 11.0 ^7-7 12.8 20.2 l»+.7 22.8 16.6 25.3 18. U 27.8 20.3 30. U 22.1 32.9 23.9 35.5 25.8 38.0 27.6 UO.*^ 20.5 ''3.0 11.3 h^.6 3.50" 9.U 6.g ^•7 g.5 lu.l 10.3 16. u 11.9 18.8 13.7 21.1 15.»^ 23-5 17.1 25.9 18.8 28.3 20.5 30.5 22.2 32.9 23.9 ■^5.2 25. S 27.-^ 39.9 29.0 1^2.3 ■?o.g U11.7 "^2.5 117.0 ■^li.2 3.75" 10.9 7.9 13.1 9.6 15.3 11.1 17.5 12.8 \l:l 22.0 16.0 2U.0 17.6 26.3 19.1 28.6 20.7 30.7 22.-^ ■^2.9 2"^. 9 ■^«S.2 2^.6 17.1 ?7.2 19.'^ 28.8 U7.9 ■^1.9 J+.OO" 10.2 l.h 12.3 «.9 l'+.3 10. i^ I6.«i 11.9 li:l 20.5 ih.S 22.6 16. »i 2U.6 17.9 26.7 19. IJ^ 28.8 20. <5 30.8 22. U •^2.9 2->1.9 ■^t^.O 25. li '6.9 ■^9.1 28. U l^l.l 29.9 U.?R" 9.7 7.1 11.7 «.5 13.5 9.8 15.5 11.2 n.h 12.7 19.3 1*^.0 21.2 15."+ 23.2 16,8 2S.2 18.-^ 27.1 19.7 29.1 21,1 10.9 22. S ■^2.9 23.9 26,8 •^8.8 ?8.'^ U,50'' 10.9 g.o 12.8 9.3 IU.6 10.6 16.'+ 11.9 18. 3 13.3 20.1 II+.6 22.0 16.0 ?3.7 17.2 2R.6 18.6 27.'+ 20.0 29.2 21.2 ■^1.0 22.6 32.9 23.9 Vi.it, T<.6 26.6 '+.75" 10.14. 7.6 12.2 8.9 13-9 10.1 15.7 11.4 17.3 12.6 19.0 13.0 20.7 15.1 22.5 16. i ?4.2 17.6 26.0 18.9 27.6 20,1 29. U- 21. U. 31.1 22.6 ■^2.0 2-^,9 5.00" 11.6 &.h 13.1 9.6 11+.9 10. s 16. «^ 11.9 18.1 13.2 \l:l 21. U 15.6 23.0 16.8 17.9 26.3 19.1 27.9 20.3 29.6 21.5 22.8 ■^2.9 2-^.9 5.25" 10.9 7.9 12.5 9.1 ii+.i 10.3 15.7 11. i^ 17.2 12.5 18.8 13.7 20.3 lli.g 21.8 15.9 ?3.5 17.1 25.1 18. 3 26.7 19. It- 28.3 20.5 ?1.7 22.8 5.50" 10.5 7.6 12.0 8.7 13.5 9.8 15.0 10.9 16. i+ 11.9 17.9 13.0 19.h lU.l 20.9 15.2 2?.k 16. -^ 23.9 17.^ 25. u 18.5 26.9 19.6 28.1; 20.6 ?Q.Q 21.8 1 5-75" 8.3 12.8 9.3 Ih.? 10.3 15.7 11. u 17.1 12.1; 18.6 13. S 20.0 II+.5 21. U 15.6 22.9 16.6 ph.T, 17.7 25.8 18.7 27.2 19.8 28.6 20.8 6.00" 10.9 3.0 1?.3 8.9 13.7 10.0 15.1 10.9 16. U 11.9 17.8 13.0 19.2 lij-.O 20.5 lh.9 22.0 16.0 17.0 2U.6 17. '^ 26,0 18.9 27. u 20.0 6.?5" 10.5 7.7 11.9 8.6 13.1 9.5 IU.7 10. u 15.9 11. li 17.0 12. U 18. U 13.3 19.7 1I+.3 21.0 15.-^ 22.3 16.2 2-^.6 l7.2 25.0 18.1 26. -^ 19.1 6.50" 11. u 8.3 12.7 9.2- 13.9 10.1 15.2 11.0 16. U 11. .9 17.7 12.8 18.9 13.7 20.2 l'+.7 21.5 15.6 22.8 16.6 2U,0 17.5 2^.3 18. U 6.75" 10.9 7.9 12. ? 8.8 13.^ 9.8 1U.5 10.6 15.9 11.6 17.0 12. li 18. 3 19.5 1U.2 20.7 15.1 22.0 16.0 23.2 16.9 2U.U 17.8 7.00" 10.5 7.6 11.7 8.S 12.9 q.U lU.i 10. -^ 11.1 16. li 11. q 17. S 12.8 18.8 11.7 19.9 1'4.5 21.1 15. »+ 22.3 16.2 23.5 17.1 7.50" 10.9 7.9 12.0 8.7 13.1 9.6 11. 2 10.3 15.3 11.1 16. U 11.9 17.5 12.8 18.7 1-^.6 19.7 ih.k 20.8 lf^.2 22.0 16.0 g.OO" 10.2 11.2 8.2 12.3 8.9 10. u. IR.U 11.2 16. 1^ 11.9 17.'+ 12.7 18, «S 13.'+ 19.5 l'i.2 20.5 14.9 g.50" 10.6 7.6 4-7 8.5 12.6 9.1 13.5 9.8 10.5 15.5 11.2 16. U 11.9 17. »+ 12.7 18.1; 13.'+ 19.3 lli.O 9.00" 11.0 8.0 11.8 8.6 12.8 9.3 13.7 10.0 lli.6 10.6 15.5 11.3 16. »v 11.9 17.3 12.6 18.3 13.3 E.r. r In. ho ft. 50 ft. 60 ft. 70 ft. 80, ft. 90 ft. 100 ft. 110 ft. 120 ft. 130 ft. 1^0 ft. ITO ft. 160 ft. 170 ft. ISO ft. 190 ft. 200 ft. SIZES GIVEN ARE TO THE NKAPE8T TENTH OF A FOOT This table supersedes all previous screen image tables [This table prepared exclusively for and copyrighted, 1932, by [Courtesy, Bausch & Lamb Optical Co.] International Projectionist] — i March 1932 INTERNATIONAL PROJECTIONIST 13 Important ! It is of the utmost importance that projectionists and theatre man- agers maintain the full aperture height of .600". As soon as the height is cut down the essential substance photographed will be lost and the situation becomes as bad as, if not actually worse than, be- fore, as studios will be composing for the full area. This point is outstanding in the work of introducing and maintaining the new uniform aperture. by the studios. This proposal was to establish a theatre aperture of .600" x .825". While . some individual theatre technicians are still urging the .590" height, the executives have agreed to the .600" X .825" and will undertake to en- force it in their theatres and bring about a uniform aperture height for the first time since the introduction of sound pic- tures. Following the same line of reasoning as for the original tentative specifications, the Academy subcommittee recommended that the studios photograph new produc- tions according to ,the accompariying specifications. The image as photo- graphed is to be .631" high by .868" wide with the expectation that after shrinkages and mechanical variations have taken place the image will be just the right size for satisfactory projection through the theatre aperture. A Break 'Down of Service Dollar, ERPVs Reply to Critics TROUBLE-PREVENTING i n s p e c- tions, appointment and emergency calls, replacement part inventories in key cities, free replacements, repairs and im- provements, general administrative ex- penses atid protection against fire loss are the things that the service dollar pays for, C. W. Bunn, General Sales Manager of Electrical Research Products, stated recently in outlining how service charges have been brought to a minimum con- sistent with ■ the maintenance of high quality of reproduction and continuous, defiendable operation. Only 4.3 cents of every dollar goes to administrative and engineering expenses. The regular inspection service takes 54.1 cents, and emergency and appoint- ment calls account for 13 cents. The former comprise the regular trouble-pre- venting inspections made by a field force of 600 who travel 5,720,000 miles annu- ally among 5,500 Western Electric- equipped theatres. Appointment and emergency calls are additional visits, the former to discuss problems of equip- ment maintenance and operation by ap- pointment, and the latter in response to an immediate emergency. Inspection vs. Service Experience gained in contact with 8,000 theatres has demonstrated, Mr. Bunn stated, that a definite relationship exists between the number of inspection and emergency calls. The latter at pres- ent average one per theatre every 18 months. Any attempt to economize by cutting down the inspection calls would automatically increase service costs by a resulting larger number of more costly emergency calls, ^ Mr. Bunn explained. Even more important, he pointed out, would be the menace of interrupted and cancelled shows resulting from lack of sufficient inspections. Where the Money Goes Thirteen cents out of every dollar goes for the maintenance of $750,000 replace- ment part inventories in 35 key cities and of 173 other service points. These assure maximum freedom from program inter- ruption because of the ability to speedily replace parts in an emergency. Out of every service dollar 4.6 cents goes for free replacements, repairs and improvements made by Electrical Re- search Products without charge to ex- hibitors. This activity was initiated last year without any increase in service charges and is estimated to have saved exhibitors $750,000 in one year. It also finances the Inquiry Bureau in New York, organized in 1931 to co-operate with exhibitors in supplying adequate in- formation regarding equipment opera- tion and maintenance. The final 11 cents out of the dollar goes for protection against fire loss. It assures the immediate replacement of any equipment or parts damaged by fire without a lost moment for technical for- malities or the signing of papers. Summing up the itemization of the service dollar, Mr. Bunn said: "We have reduced charges to the abso- lute minimum consistent with satisfac- tory reproduction and the greatest pos- sible promise of continuous, dependable performance. In our estimation these are the foremost box office considerations. Whenever we have been able to effect economies without jeopardizing them, we have promptly passed on to the exhibitors the savings in the form of reductions in service charges. "The best assurance that we have acted wisely in placing quality reproduction and steady performance first lies in the fact that only 5 per cent of the Western Electric-equipped theatres are closed to- day as compared with 50 per cent dark houses among theatres with competi- tive types of equipment. We are unable to escape the conclusion that the quality of sound and its steady dependability of operation have been big factors in en- abling Western Electric-equipped thea- tres to hold patronage and make such a favorable record, by comparison with others, under present conditions. We feel that every cent we have asked of exhibitors in service charges has been justified by actual box office considera- tions to their advantage; and the record of closed theatres would seem to support our contention." TELEVISION 'OVERSOLD' TO PUBUC, SAYS R.M.A. MANY problems remain to be solved before television can become a satisfactory means of home entertain- ment, says the Radio Manufacturers Association, in a statement on the present status of this broadcasting development. Declaring that television and its pros- pects have been very much oversold to the public, and that it is still a question how it will be possible to obtain sufficient revenue, either from advertisers or by taxing the public, to meet the added cost of staging television programs, the asso- ciation cites the following as the most important technical obstacles still to be overcome : Technical Problems 1. Greater detail should be obtained in received picture. 2. Television transmission pick-up equipment should be portable and as easily used as present-day sound picture pick-up equipment. 3. Transmitting systems must be evolved which will have a satisfactory and reliable service range. 4. Receivers as simple in operation as our present radio receivers must be de- signed and built at a reasonable cost. 5. Quiet and satisfactorily illuminated picture equipment for the home must be designed and built at a reasonable cost. Bob Gray has been elected president of Local Union 546 (Lowell, Mass.) for the tenth consecutive time. Other officers are Sidney E. Bow, re-elected business representative; Maurice Cooper, treas- urer; and Sidney Barton, secretary. FIG. 2. BEAM DIRECTION IN NEW PROJECTOR a — parabolic mirror; b, c, e — lenses; d — tilting mirror; f — prism; g — film; h — adjusting mirror; i — diapositive (slide), mirror; i, k, I — projection lenses FIG. 1 SCHEMATIC OF THE PRINCIPLE OF OPTICAL COMPENSATION i a — film; h — spindle; c — tilting mirror ; d — spindle ; e — fixed mirror; f — screen; 1, 2, 3 — positions of picture ; b — diaphragm ; 1', 2', 3' — positions of tilt- ing mirrors CONTINUOUS PROJECTION BY OPTICAL COMPENSATION First publication anywhere of data (direct from Germany), relative to the new Mechau sound-film continuous projector H. A. Robiczek Copyright, 1932, by James J. Finn Publishing Corp. Reproduction in whole or in part without permission forbidden. IN order to present a moving picture it is known to be necessary to pro- duce a stationary object before the eye in a rapid succession of pictures, each of which presents a timely and spa- tially different position, although the in- terruptions may not become too large. Processes of movement of everyday life, taking a minute have to be retained in about 1,000 film pictures, if jerky move- ments are to be avoided in the repro- duction. According to the principle of jerk (intermittent), conveyance of the film which, together with the Maltese cross and the shutter, have experienced gen- eral technical realization, the succeeding film pictures are presented to the eye in a really stationary position. The change from one picture to another, i.e., the film conveyance, is kept completely invisible to the eye, because of the shutter. Through the protrusion of the shutter, intervals of darkness originate between the individual pictures, causing an unin- terrupted change from light to dark. This continual change affects the ocular nerves and, through these, the brain and head nerves of delicate persons to a high degree. The personal discomfort to which such spectators are subject often is re- flected in subsequent derogatory state- ments relative to the motion picture in- dustry. In addition, film and mechanism, during jerky transport, are subject to particularly heavy wear, and films al- ready showing perforation defects are not conveyed properly by the switch gear, thus not permitting maximum efficiency of presentation. The Mechau Development For these reasons, it has been the aim of expert workers since the introduction of motion pictures to replace the jerky film conveyance with a device for optical compensation of the film movement. All makers of motion picture projectors have tried their hand at solving this problem; hundreds of patents of the most varied description relating to this phase of the art have been filed, at enormous cost; but the actual solution was only recently achieved by E. Mechau, in cooperation with the Leitz Works, Wetzler, Germany. With an apparatus with optical com- pensation of film conveyance, the indi- vidual pictures are no longer projected during the stationary position of the film, but during uninterrupted film convey- ance. A part or entire revelation of this continuous film conveyance through a shutter, such as in Maltese cross projec- tors, would thus be superfluous. On the other hand, an optical device to project still reproductions from the continually [14] moving film tape on to the screen be- comes necessary. Great difficulties were encountered in endeavoring to make the film movement invisible on the screen through an optical device including movable lenses, prisms and mirrors, and to move the projection of one film picture into that of the next one without pauses of obscurity. The idea of the optical compensation device of this machine is as follows: Projection Process If a film picture is situated at 1 (Fig. 1), and the mirror c is in position 1', re- production on the screen is caused at /. If now the film picture moves downward into position 2, a corresponding transfer of the reproduction on the screen is caused, if mirror c remains in position 1' during the movement. If, though, it is simultaneously brought into position 2', the reproduction remains at /, and its movement on the screen is optically com- pensated for. The same condition pre- vails if film picture and mirror arrive in position 3 and 3', respectively, at the same time. In the same instant the following film picture appears at 1, its movement also having to be compensated for. For this purpose the mirror c also describes a revolving movement around its spindle h March 1932 INTERNATIONAL PROJECTIONIST 15 simultaneously with the tilting already mentioned, from position 1' to 3', and leaves the beam as soon as it reaches position 3'. Continuing, a second mirror commences the same route through the beam into position 1' and terminates, similar to its predecessor, in position 3'. Thus the movement of the second film picture is cancelled, and the third mirror enters the beam. In this manner eight sectoral plane parallel mirrors revolve about the spindle h, and a suitable gearing of the mirror turning device and the film conveyance ensures exact synchronization of film transport and compensating device. As the mirrors succeed one another without break, parts of two sector mirrors are simultaneously present in the beam for a minute space of time during each change of film picture. Compensating Action While one mirror is still compensating for the movement of a certain film pic- ture, the next mirror has already begun to do the same with the following picture, so that in each change of pictures the reproductions of two successive pictures are transposed on top of each other on the screen. In the^ same measure now [as during the movement of the pictures, the receding mirror is caught by a grad- ually decreasing part of the beam, and the following mirror receives a propor- tionally increasing part of the light beam], the clearness of both transposed reproductions on the screen gradually changes, but leaves the actual clearness unchanged. Thus, without dark inter- vals, one screen view will always fade into the following, without enabling the Fig. 3. — Mirror mech'inism as seen from front and reverse eye to detect any change-over at all. The reason for this is that the movement of the tape, i.e., the change of pictures, is faster than can be followed by the eye. Only at speeds of less than 8 to 10 pic- tures per second is the changing of one picture into the next one visible. To avoid losing the extra light gained by the dropping of the shutter, through simultaneously projecting several film pictures, the projection beam in the film track must be moved in synchronism with the movement of the film tape. There- fore, a highly illuminated, square front window is projected on to the individual film pictures through a special objective, and the light beam projected on to the same mirrors before the film that effect the optical compensation behind it. Thus the sector mirrors are made use of twice, and produce vibrations in the beam also before the film, that cause the reproduc- tion of the front window to advance with the individual pictures to a certain dis- tance in the film track, then disappearing downward, to reappear above subse- quently. For the practical employment of the apparatus in scientific institutes it is of greatest importance that the clearness of reproduction remain constant, as it is thus possible to reduce the operating speed down to about 2 or 3 pictures per second; at this frequency, the individual pictures are clearly distinguishable, and enable an exact observation of even the slightest degree of development. The full construction of the apparatus ready for use is shown in Fig. 4. The mirror arrangement is enclosed, oilproof and dustproof, in the inclined drum. Fig. 3 shows the front of the opened mirror casing, from which all sector mirrors except one have been removed to convey a better idea of the construction. The tilting movements of the individual mir- rors causing the optical compensation are effected by the sliding of guide pins in a link of a special curved shape. Recent Improvements The latest Mechau model (Fig. 3), is remarkable for its particularly high de- gree of accuracy, and has been greatly improved and its efficiency increased to meet modern requirements in every way. Because of the uninterrupted, not jerky, film conveyance the machine runs almost noiselessly at any speed, and vibrations are entirely avoided. The constant and ■J 1 j i K li mm j^^HBv ^^vW 1 ac,^ IH| ■yr\ 1 ' ■ j^SSf^Su^^KL. iBn 11 a^CHbIRi S Fig. 4. — Full vieiv of projector showing friction gear Fig. 5. — Projector with opened film guide and (at left) sound ray appliance 16 INTERNATIONAL PROJECTIONIST March 1932 vibrationless operation of the apparatus Makes it particularly suitable for sound- film reproduction; in fact, these features practically predestine this machine as the sound projector of the future, as of course, the sound film tape requires an entirely even run through the apparatus, and an absolute synchronism is attained through the even conveyance of the pic- ture as well as of the sound film. A further advantage, of special im- portance for sound film reproduction, is the noiseless operation of the driving mechanism. Scraping of the film, more or less present in all Maltese cross ma- chines, cannot occur in this new appara- tus. The careful handling of the film through the constant conveyance and its excellent guiding are advantages by which the sound film profits, since in the sound film considerable sound in- terruptions may be caused through the slightest damage to the film tape. The sound-ray apparatus developed for this machine combines with the projec- tor, as seen in the illustration, to an entirety. It is directly set onto it, and is driven by a gear fitted to the main spindle of the projector — thus variations in speed cannot develop between the pro- jector and the sound reproducing appli- ance. For theater use the machine is to be preferred not only for its particular adaptability to sound film reproduction, but also because of its good protection against danger of fire. A self-acting shutter worked by a mercury pump auto- matically cuts off the projecting appara- tus and the film guide from the arc lamp as isoon as a speed below the admissible one has been reached. The film drums are located horizon- tally, thus ensuring most careful mani- pulation of the film, of which reels con- taining to 4,000 feet can be employed. Special long leads to' the , drums cause burning film being drawn into the drum to be extinguished. The source of illumination is a mirror- arc lamp with automatic carbon adjust- ment, contained in a double-walled lamp casing lined with asbestos. Slide Projection For the projection slide plates, etc., the light of the arc lamp is thrown up- ward by a folding mirror, contained in the lamp casing, on to a second mirror. From this the ray is projected through the diapositive and through a special ob- jective in the usual way. Thus with the aid of the folding mirror in the casing, changing-over from film or sound-film reproduction to dia-projection is possible without any adjustnient of the machine. To obtain stepless speed regulation of the film picture, a friction gear is fitted between the motor and the mirror mech- anism— this permits a minute speed regu- lation and allows the speed adjusted when starting to be kept constant with- out the necessity of any readjustment. The usual method of regulation by means of a resistance starter may enable an accurate degree of adjustment 'to be attained, but not a constant speed, as the ordinary resistance will vary in pro- portion as it becomes heated. The stopping device' often provided in Maltese cross machines is not required in this apparatus, as the optical compensa- tion in itself already periliits a speed reduction down to about two changes of pictures per second'. ' " Comparative Worth of D. C, Power Sources (Addenda) I REFERRING to the article in your February issue by Samuel Bagno, regarding comparative worth of D.C. power sources, we have a few comments to make in connection with our experi- ence along these lines. We have found that small compact mo- tor generators of the single unit, two- bearing type prove very satisfactory for furnishing power -to the exciting lamps and to the field circuits of the loudspeak- ers.' A 4,000 mfd. electrolytic condenser connected across the generator terminals provides sufficient voltage for the most •exacting conditions when the power is jjteing furnished to the exciting lamp. No filter at all is necessary in connection v/ith the field circuits of the loudspeakers. M. G. Economy We believe that motor generators of proper design are more economical for exciting lamp and horn field supply than any other source of power available, when all of the costs, including mainten- ance costs, are takfen ihto consideration. The motor generator may be furnished with wool-packed sleeve bearings of. lib- eral design, which require very infre- quent lubrication. A few drops of oil every two or three months is all that is required. Bearings of this type require practically no more attention than ball bearings, and are quieter running. As far as the brushes and commuta- tors are concerned, if brushes of proper composition and design are used, there will be practically no wear of the commu- tator and only infrequent changing of brushes. The maintenance expense in- volved in connection with bearings, com- mutators, and brushes is practically neg- ligible. The motor generator is furnished with very close voltage regulation, so that one or two exciting lamps may be operated Esco two-bearing motor-generator set, with panel from it with very little change in voltage. This condition is not obtainable in other forms of power supply. Motor generators may also be fur- nished with suitable filters for supplying power to all of the tube filaments, in addition to the exciting lamps and field circuits of the loudspeakers. It is im- portant to provide sufficient filters for each of the circuits, and to be Careful that all the leads, etc., are shielded with metal. By this arrangement, the filtering is adequate to prevent objectionable noise in the loud speakers, and the voltage is maintained constant, whether one or two exciting lamps and photo-cell amplifier filaments are being operated at once. It is probably advisable to use dry bat- teries for the photo-electric cell itself, but all of the other low voltage powter supply often obtained from storage bat- teries may be obtained from motor gen- erators with less maintenance expense, more reliability, and much less frequent replacements. William H. Haines, Electric Specialty Co., Stamford, Conn. 3,124 Advance Orders for New Cameron Book "Questions' and Answers," the new book by James R. Cameron and which is published by the Cameron Publishing Co., Woodmont, Conn., is proving to be the most popular projectionist book ever marketed by this company, according to an announcement of pre-publication or- ders received to date. More than 3,124 orders have been received for "Questions and Answers" prior to publication, and there is every indication that the 5,000 mark will be reached before publication of the volume on April 1. Advance sales on this latest book is another indication of the leadership of Cameron books in the projection field. A large majority of projectionists buy Cameron books upon announcement and sight-unseen, so well established is the Cameron trade mark of quality. Inquiries on "Questions and Answers," as well as on all other Cameron books, may be ad- dressed to Cameron Publishing Co., Woodmont, Conn. March 1932 INTERNATIONAL PROJECTIONIST 17 A message to the Motion Picture Theatre Owners of America A most important announcement was deliv- ered at the Allied States Convention in Detroit, and the M. P. T. O. A Convention in Washington by the Photophone Division of the RCA Victor Company. It was at the same time the most impor- tant announcement exhibitors have heard since sound became the screen's most domi- nating factor. Cut to the bone and right down to the solid facts, it is herewith transmitted to motion picture theatre owners of America, large and small, from the largest circuit to the indi- vidual exhibitor. Before one or the other contemplates the installation or replacement of sound repro- ducing equipment, investigation of the fol- lowing information is respectfully suggested: The Photophone Division of the RCA Victor Company announces The introduetion of two new all AC operated sound reproducing equip- ments, the Standard Super, designed for theatres from 2,500 to 4,000 seat- ing capacity at $5,000 and Standard Large, for theatresJbetween 1,400 and 2,500 seating capacity at $3,750. Reduction in the price of the Special Size equipmentfrom $1,600 to$l,450. Other material reductions including contract service charges, all made pos- sible by the recent merger of the RCA Photophone Co, with RCA Victor Co., Inc. Increases in capacity limitations of all A C operated Special Size equip- ment from 500 to 600 seats and all AC operated Standard Small Size equipment from 1,200 to 1,400 seats. For further information communicate j[pa>-y Bosto'.Mass. 5-1*3 AMERICAN PROJECTION SOCIETY, INC. ■ CALIFORNIA CHAPTER No. 7 >'o.^_MG__ LosAngelks, .^ 19i?-^ The mark of a quality projection paper PiKTTO TBB ORDER O] ^-jf^i^^^i^^^^^^k^ ^..^^^;^:i^:e!^^<^a^ - ■■ji /^^ ?C^ "^l-Doi.^A.na CITIZENS MIM^Mi BANK ^/-^. CiYcidation Others Claim It We Prove It! CLAIMS of large circulation are easily made but less easily proven. Interna- tional Projectionist has no trouble at all in proving its nationwide circulation — paid for directly to the publisher by its readers. I. P. has no agents, no solicitors, and spon- sors no premium or contest "gags" in con- nection with circulation. Further indication of the widespread circulation support accorded I, P. Organization officers insure their nvem- hers receipt of I. P. regularly by subscribing in bulk International Projectionist today has the largest volume of "pure" direct-paid cir- culation among projectionists of any paper in the field. Something more than reader interest contributed to the building of this premier circulation and that something is reader loyalty — loyalty that makes an I. P. booster of every subscriber. In prestige as well as in circulation I. P. easily tops the field. I. P.'s dominant cir- culation is in itself proof of prestige. I. P. is the practical projection journal for the practical projectionist. I. P. is 'way out front and gaining steadily. Use this blank to record your sub- scription and insure receipt of tdl copies- If you are tdready a subscriber, pass along this blank to your brother projec- tionist. 1 Year . 2 Years. ,$2.00 .$3.00 INTERNATIONAL PROJECTIONIST 1 West 47th St. New York, N. Y. Date. 193. Enclosed is $ for year(s) subscription to begin with . issue. Name Address City . . . Local . . State . ^SOFT' AND ^HARD' LIGHTING WITH SUPERSENSITIVE PANCHROMATIC FILM James J. Finn THE volume and nature of comment induced by a recent article' on motion picture lighting by the present writer indicatec^ a widespread reawakening of interest in this topic which is of such vital importance to the present and future welfare of the indus- try. While photography in itself is not regarded as being of primary import- ance to those who are interested mainly in the field of reproduction, it should be, for the reason that photographic values eventually may be translated in terms of projection values wherever motion pic- tures are shown. It is axiomatic that nothing beyond that which is contained in the film print can be projected upon the screen. So much for the importance of the subject. Among the mass of comment received in connection with the article previously mentioned were several pointed sugges- tions bearing on the desirability of de- veloping in detail the statements which appeared therein — or, in other words, a demand arose which might best be ex- pressed by the query: "What are the facts in this matter?" The task of pro- viding the answer to this query will be essayed in this article. The advent of supersensitive panchro- matic film has introduced a new element into the quality of photography obtained from various sources of illumination. The older conceptions of "soft" and "hard" lighting have been practically reversed by the introduction of this new and faster photographic material. Contrast vs. Speed The panchromatic film in use prior to 1931, while sensitive to yellow, orange and red, was much more sensitive to blue and violet. The panchromatic car- bon arc and the incandescent tungsten filament lamp, both much stronger in yellow, orange and red rays than in green, blue and violet, compensated for the low sensitivity of the film at the red end of the spectrum. This gave a wide range of gradation, approximately orthochromatic color rendering and a soft pleasing quality to pictures made under this type of lighting. The white flame carbon arc differs from the panchromatic arc and the tungsten filament lamp in that the energy emis- sion is approximately the same for all colors. Color rendering in photographs made under white flame carbon arcs con- sequently conforms closely to the color sensitivity of the emulsion. With the older panchromatic film, white flame arcs reproduced blue and violet in very light tones, while red and orange were relatively much darker. This resulted in pictures with very sharp contrasts and led to the use of the term "hard" lighting in referring to the white flame carbon arc. This over-correction of blue and under-correction of red could be equalized by the use of filters, but only at a loss of speed. During the past year new panchromatic materials have been introduced to satisfy the demand for increased speed. Im- provement has been attained largely through increased sensitivity to red, or- ange and yellow. This improved sensi- tivity to the longer wave-lengths has greatly increased the speed permissable with daylight and the white flame carbon arc, but even greater relative increase in speed has been made possible with panchromatic arcs and incandescent lighting, since these sources are strong- est in those colors to which the sensi- tivity has been increased in greatest pro- portion. The change in relative sensitivity of these new photographic materials to the blue and red portions of the spectrum has an influence on the quality of pho- tography which is of great importance to not only the photographer but to the industry as a whole. Reversed Color Sequence Decided over-correction of red, orange and yellow result when panchromatic arc or incandescent lighting is used without a suitable filter. The same sharp con- trasts and "hard" effects obtained with white flame arcs on the old panchromatic film, are now obtained with this new material from the more yellow sources of illumination. The principal difference is that the color sequence is reversed. Red is now reproduced too light, orange and yellow practically white, and green and blue much too dark. In addition to sharp contrasts, this results in decided flatness and poor modeling of flesh tones. The white flame carbon arc, on the other hand, is well adapted to the color sensitivity of the new film, giving excel- lent gradation for all colors and a pleas- ing softness of pictorial effect. Former conceptions are now reversed. "Soft" lighting means white-light; while "hard" effects result when yellow, orange and red rays predominate. Comparative Tests The foregoing facts are clearly illus- trated by a series of still photographs made under various sources of illumina- tion on film sensitized with the same material now used in the motion picture studios. Exposures were first made to deter- mine the relative speed of this film with different sources of illumination, using a subject free from color. The subject was an eight-by-ten-inch chart composed of five bands of neutral gray ranging from white through three intermediate shades of gray to black. A small portion of this chart is illustrated in Fig. 1. This chart was photographed in full size under three different types of illu- mination— white flame carbon arc, pan- chromatic carbon arc, and clear bulb incandescent tungsten filament lamps. All three light sources were placed in the same position relative to the subject and were operated at the same line wat- tage. No filter was used in this or the subsequent color test and all light sources were unscreened. With each negative the film holder slide was first withdrawn one inch and a brief exposure made. The slide was then withdrawn another inch and the negative given a second like exposure. The completed negative, exposed in this manner, comprised ten bands of expos- ure, representing intervals in the propor- tion of one-to-ten. Fig. 2 illustrates the appearance of the negative thus obtained. All three negatives were given the same development, and by comparison Figure 1 ' "The Indictment Against 'Soft Lighting'," by J. J. Finn, International Projectionist, December, 1931, Vol. 1, No. 3, p. 20. [33] 34 INTERNATIONAL PROJECTIONIST March 1932 Figure 2 for blocks of equal density it was pos- sible to determine the relative photo- graphic speed of the three light sources for supersensitive panchromatic film. The equivalent exposure times, thus de- termined, were in the proportion of 10 for the white flame carbon arc, 12 for the panchromatic carbon arc, and 30 for incandescent illumination. These factors of equivalent photographic effect apply, of course, to an even balance of all col- ors, such as given by a reflecting surface of neutral gray. Reaction to Color A second test was then made to de- termine the reaction of this film to color under the same light sources. In this test, a fourth quality of illumination was introduced: a combination of white flame and panchromatic carbons. The subject chosen for color compari- son was a basket of fruit containing to- matoes of deep red color, a pepper of Latest Bull-etin Our roving correspondent wires in the following dispatch from the hinterland, so that our readers may not be without at least one hearty laugh this month: "Operators' locals throughout the country are expected to follow the lead of Local 306, New York, in accepting 10 per cent reduction in wages from major circuits affiliated with producing compa- nies. These Ideal organizations are un- derstood to havB' been waiting for Local 306 to deterinine a course in the situa- tion. Representatives of the circuits are expected to immediately start negotia- tions with the locals in an effort to bring about a reduction." lighter red, pears which blended from red to yellow, a peach, oranges, bananas, lemons, a cucumber, a green pepper, a plum and concord grapes. The weave of the basket was untinted, but the rims at top and bottom were a deep orange color. There being a wide range of variation in the color of fruit, a chart of three standard colors was placed immediately back of the fruit basket to afford a defi- nite basis of comparison. The blue panel was a blend of 25 per cent Prussian blue with 75 per cent No. 1 white; the green panel was emerald; and the red, Vermil- lion. Back of these color panels was placed the chart of neutral grays used in the previous speed test. The upper part of this chart is visible in the illus- trations showing five blocks ranging from white through three tones of gray to black. The same stop was used on the cam- era for all four exposures, the negatives given the same development and the prints identical time and treatment. Ex- posures were adjusted in proportion to the information obtained from the speed test, the relative exposure being 10 with white flame carbon arc, 12 with panchro- matic carbons, 11 with the combination of white flame and panchromatic carbons, and 30 with incandescent illumination. Distance from the subject, direction of light and line wattage, as in the speed test, were the same for all sources of illumination. The four photographs thus obtained are here reproduced, without retouching, with legends indicating the source of illumination and the relative exposure time. Comparison of the band of neutral gray tones at the top of each photograph shows that, in a photographic sense, these four exposures were identical al- though the actual time of exposure var- ied over a range of one to three. It will be appreciated, of course, that with a subject in which the redder tones pre- dominate, the speed advantage of the white flame carbon arc would be less than that indicated by these tests ; while, with a subject in which green, blue and violet tones predominate, this advantage would be greater. Conclusions This series of photographic tests clearly demonstrates the accurate ren- dering of color values, excellent grada- MOTION PICTURE THEATERS THROUGHOUT THE WORLD 1931 Courtesy, Motion Picture Division. U, S. Dept, of Commerce March 1932 INTERNATIONAL PROJECTIONIST 35 Panchromatic Carbon Arc Relative Exposure 12 White Flame Uppers — Panchromatic Lowers Relative Exposure 11 "J" »>> -, BLUE GREEN RED L^^SnsK ^.* Jg^vCvvV^^'' White Flame Carbon Arc Relative Exposure 10 Incandescent Tungsten Filament Relative Exposure 30 ILLUSTRATING COMPARATIVE EFFICIENCY OF VARIOUS UGHT SOURCES Thh series of unretouched photographs clearly demonstrates the superiority of white flame carbon arc illumination for use with supersensitive panchromatic film, judged on basis of (1) remarkable depth, creating an atmosphere of reality; (2) full roundness of modeling, giving true impression of form; (3) distinct separation of colors and natural blending from deep to lighter hues; (4) accurate reproduction of color tone values, with no over-correction and consequent flatness; (5) pleasing softness of pictorial effect combined with sharp definition of details, and (6) striking advantage in photographic speed tion, superior modeling, absence of over- correction and consequent flatness, pleas- ing softness of pictorial effect combined with sharp definition of details, and the striking advantage in photographic speed obtained from white flame carbon arc illumination with supersensitive panchro- matic film. This, then, is the answer to the query: "What are the facts in this matter?" While the accompanying reproductions of untouched photographs in themselves tell the story, a resume of the conditions under which the tests were conducted, in addition to certain data relative to sensi- tivity and speed of emulsions, would seem to render doubly effective the story told by the pictures. iVeit; Developments New developments in carbon arc lamps providing silent operation, steadiness of burning, remote control, and freedom from costly maintenance are soon to be announced to the motion picture indus- try. The near future therefore has in store for the industry a light source which will meet its most exacting de- mands for speed, excellent photographic reproduction, economical operation and increased comfort on the set. The writer is indebted to those who aided in the gathering of the material presented in this article, and in particu- lar to the Research Department of Na- tional Carbon Company for the use of the illustrations and other data which originally appeared in a technical publi- cation issued by the Company. ^■^ ■j^i ^'-"^R^y ..-:V:''' Type 79-A Visitron for Western Elec- tric, Preddey and Ultraphone equip- ments. Better Sound and Lower Maintenance NSTALL VlSITRONS and FORGET THEM! Photoelectric cells are the heart of your sound equipment. If your cells are weak, your sound re- production is "wobbly" and you're not getting maxinnum results from your equipment, either in quality or quantity. Put in Visitrons and this vexing problem is solved — permanently. You can then forget you are using photoelectric cells for a year — perhaps two years. Visitrons are that good, yet they cost no more than others. You don't have to take anyone's word about the brilliant sound repro- duction afforded by Visitron Photoelectric Cells. Just try one! Any National salesman or service man will gladly demonstrate Visitrons right on your own equipment. ISITRON Manufactured by G-M LABORATORIES [NC, 1737 Belmont Ave., Chicago, III. Order Them BY NAME from 'national theatre supply company I ROJECTIONISl fd/fecfby James J. fmn The Big ALL TUBES FOR EVERY MAKE OF FILM AND DISC A P P A R A TU S . . . A complete line of Duovac Tubes is available for every standard and special make of sound projection equip- ment. The Duovac staff of engineers is always ready to advise you without obligation on your require- ments, no matter how small they may be at the moment. Show The Way There's hardly a big" chain or important house* that hasn't adopted Duovac Tubes and Photo Cells after exhaustive tests in actual service — uninfluenced by name, claim or pressure. They found, as you will find, that Duovacs save at least $5 out of every $10 spent for tubes. Startling- — but no mystery. Lower first cost and longer life turn the trick. Quality of performance? The De Luxe houses* have maximum standards and Duovac is the pet of their projectionists. Write today for the whole Duovac story — you'll find it straight and to the point. - NAMES ON REQUEST DUOVAC RADIO TUBE CORP. 360 FURMAN STREET, BROOKLYN, NEW YORK Vol. 2, No. 4 JuiM'. 1932 A magazine devoted to better visual and sound reproduction 25c. a C4 $2.00 a y For better quality picture and sound r e production i Lightweight — yet sturdy, rigid and durable The Projection Reel Designed by a Projectionist for Projectionists i\ O seams, no brazing and no welding to break open or come apart when rewinding or while in the projector. Made of a special aluminum alloy which results in a lightweight yet sturdy and rigid reel. No rough edges to cut the fingers or damage the film. The True Reel for Projection Sold by All Leading Dealers PRICES: 15 in. reel with 5 in. hub $3.00 each 11 in, reel with 5 in. hub $2.50 each i Manufactured by W. & W. Specialty Co. 241 Lafayette St. New York, N. Y. June 1932 INTERNATIONAL PROJECTIONIST Strong Electric Change-overs FOR REAR SHUTTER MOUNTING The "Super" For mounting on a rear-shutter Simplex or at the port opening for use with any projector Specifications: Cast aluminum housing. Black crakle finish. Aluminum blades. Asbestos cover- ing. 110- volt coils (specify whether A. C. or D. C. wanted). Patented automatic current cut-off which cuts the current off the coils auto- matically. You Can't Burn Out the Coils Furnished with 5-foot lead wires and conduit. A space is provided to install op- tical glass when mounted each at the port opening. $40 FOR FRONT WALL MOUNTING The "Special" A new member of the famous Strong family of high-grade dec- trictd projection equipment Exactly the same in every way as The "Super" except that it does not in- clude the automatic current cut-off feature. The greatest value in an electric change-over available today. All orders should specify whether for rear shutter or port hole mounting and whether A. C. or D. C. coils are desired. 130 each The name "^Strong" on a change-over has stood for precision projection work for more than 15 years. There is no substi- tute for a Strong Change-over. Sold and Serviced by All Leading Dealers. Manufactured by ESSANNAY ELECTRIC MFG. CO. 1049 No. Hermitage Ave. Chicago, Illinois INTERNATIONAL PROJECTIONIST June 1932 A NEW BOOK BY CAMERON QVESTIOIVS & ANSWERS (SOUND MOTION PICTURES) THE SUBJECT OF RECORDING AND REPRODUCING OF SOUND MOTION PICTURES COVERED IN QUESTION AND ANSWER FORM Here are 35 of the 542 questions that Canadian projectionists must be able to answer correctly to obtain a "grade A" card. HOW MANY OF THESE CAN YOU ANSWER CORRECTLY? If excessive plate current develops, what would you do? How is amplijficatioii accomplished? "Would any kind of synchronized motor or constant speed' motor do for sound projection? Why are all the wires carrying sound or speech, lead covered and again en- closed in conduit? What is the "gain" control, and what are its functions? What would a low plate reading on the panel indicate? How many tubes in a D. C. and A. C. motor control cabinet? The photo-electric cell has a silvered lining, and one wire is connected to the lining. Is this wire positive or negative? Does the voltage to the photo-electric cell cause a steady current flow? What and where is the grid leak in the amplifier? What is the function of the exciting lamp? What is the action of (a) the plate (b) the grid (c) the filament in a va- cuum tube? What might result from placing motor generator sets and batteries in the same room? Explain what a rectifying tube does? What is "specific gravity"? What are the causes of motor-boating? Why does the needle on the disc travel from the centre of the disc to the out- side? On Vitaphone disc, is the sound rec- orded on the bottom of the track or groove, or is it cut into the walls of the groove? What apparatus "do the "H" batteries supply with current on W. E. and N. E. equipment? Should all motor generator sets be grounded? If so, state why. What is a prismatic condenser? When using a prismatic condenser, will the condenser be closer to the aperture than if you used a piano condenser? Can a prismatic condenser be used when showing slides? When using a Cinephor condenser sys- tem, is accuracy in the focal distance of much importance, and why? Can a cracked mirror or condenser be used with mazda projection? "What will be the result on the screen? What is the average amperage on (a) high intensity (b) reflector arc (c) fal- low arc? If the voltage drops, what effect will the cutting out of resistance have? In an electric arc circuit, what various things offer resistance to the flow of current? What is the standard aperture size? Why does a cracked condenser show up when projecting slides and not when projecting film? Define the following: collector lens, piano lens, meniscus lens, converging lens, condensing lens. What is absorption of light? What is the optical axis? What causes film to buckle, and what effect has this on the screen? Which make of projector has an actual faster movement — that is, the movement of the intermittent from full rest to full rest? All of the 542 Canadian examination questions, with several hundred others, are answered for you in this new book. The subject of Sound Motion Pictures fully explained in an "easy-as-A. B. C" manner. 240 PAGES— OVER 1,000 EXAMINATION QUESTIONS WITH ANSWERS— PRICE $3.50 CAMERON PUBLISHING CO. Woodmont, Conn. Here is my Three dollars fifty cents, send me my copy of QUESTIONS AND ANSWERS ON SOUND MOTION PICTURES. Name Address I. p. June 1932 INTERNATIONAL PROJECTIONIST PROJECTIONISl Edited by James /• Finn Volume 2 JUNE 1932 IS umber 4 Monthly Chat 5 Testing for 'Shorted' Filter Condensers 7 A. C. SCHROEDER 31st I. A. Convention at Colum- bus 9 Convention Arrangements Com- mittee 10 Convention Delegates 11 Convention Sidelights 12 Motion Pictures in Relief 13 Sound School Mail Fraud Im- prisons Two 14 James J. Finn P. A. C. Welcomes Hausner in Miami 15 Practical Problems of the Pro- jectionist 16 Theatre Problems of the Release Print 18 A Tribute Well Earned 19 Rectifier Power Supply for Sound Systems 20 B. F. Heyer and W. F. Bonner Philosophic Background of Unions 22 Sumner H. Slighter, Ph.D. Notes From the Supply Field 23 News and Views 24 Miscellaneous Items News Notes Technical Hints Published Monthly by JAMES J. FINN PUBLISHING CORP. 1 WEST 47th STREET, NEW YORK, N. Y. West Coast Representative Hallett E. Cole, 218 Haas Building, Los Angeles, Calif. ('Phone: Tucker 6428) Subscription Representatives Australia and New Zealand: McGills, 183 Elizabeth St., Melbourne England and Dominions: Wm. Dawson & Sons, Ltd., Pilgrim St., London, E. C. 4. ■ Yearly Subscription: United States and possessions, $2 (two years, J3) ; foreign countries, S2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Entered as second-class matter February 8, 1932, at the Post Office at New York, N. Y. under the act of March 3, 1879. Entire contents copyrighted 1932 by James J. Finn Publishing Corp. International Projectionist is not responsible for personal opinions appearing in signed articles in its columns. MONTHLY CHAT OUR belief that International Pro- jectionist is a great craft publica- tion was confirmed at the I. A. Conven- tion held in Columbus. One who never forgot sales for an instant in Columbus mounted the rostrum of the Convention and proceeded to define a craft publica- tion. We were amazed to hear a certain publication which purports to serve the projectionist craft described as strictly non-partisan, wholly technical in nature and absolutely uninterested in pohtics and policies — not to mention person- alities. I. P. wasn't mentioned by name but by implication. Not that we care a whoop, but. . . . We can't let pass the opportimity to castigate this fellow who thought to in- gratiate himself with the officers and dele- gates by baring his breast and showing the imprint thereon: "Safe and Sane." We can think of many arguments in sup- port of the contention that any paper which professes to shun politics and policies, and to avoid personalities, is simply taking money from its advertisers and subscribers on a sneak-thief basis. Probably the best argument again*.' these whimpering publishers who seek to curry favor (and dollars), by the cry of "Safety First" was that loosed recently by Mr. G. B. Parker, editor in chief of the Scripps- Howard newspapers. Said Mr. Parker: "There are two kinds of newspapers. Both print news. Both have editorial pages. But there the similarity cease,-. For, on the editorial pages of the one kind you will find opinion. In the other you will not. "In the first you will learn what tlie editor thinks, for example, about the mayor, or the administration in Washing- ton, or the tariff, or the League of Na- tions, or prohibition. You may not agree with the editor,. But at least you will know where he stands. "From the other kind of editorial page you will find, instead of opinion, merely emasculated reading matter. Non-provo- cative subjects such as fresh air, spring and sunshine will occupy the columns. Occasionally the editor may go on record in behalf of good heahh and against disease. But he will not be so explicit as to offend. Perhaps he will oppose war, but no particular war. In one of his bolder moments he may declare against the smoke nuisance. But he will never pick on any specific chimney. "Both kinds of newspapers are useful. But the first, in my opinion, is infinitely more useful than the second — and I am sure it is more interesting." MODEL R PROJECTOR REGULAR PROJECTOR "NEGLECT IS FALSE ECONOMY" REAL ECONOMY IT PAYS TO USE TRADE MARK REG'O. PROJECTORS IT PAYS TO KEEP YOUR PROJECTORS IN GOOD REPAIR AT ALL TIMES WITH GENUINE TRADE MARK nee'D. PARTS BETTER PROJECTION PAYS INTERNATIONAL PROJECTOR CORPORATION 90 GOLD STREET NEW YORK INTERNATIONAL PROJECTIONIST VOLUME II NUMBER 4 JUNE, 1932 TESTING FOR 'SHORTED' FILTER CONDENSERS A. C. Schroeder MEMBER OF LOCAL UNION 130. LOS AJVCELES. CALIFORNIA FILTER condensers are used to filter or "smooth out" the current before it reaches the plates of the ampli- fier tubes. They remove the hum which would be present if the supply were to be used just as it comes from the recti- fiers. They also act as a reservoir to store current and keep it in readiness so that it can be used for peak loads, which occur when the reproduction is very loud, especially on the lower frequencies. When one of the filter condensers punctures, the show stops; or should we say when the show stops, how do we know if the trouble is a filter condenser? If the condenser shorts completely, the sound will stop at once. The reproduc- tion will be good until the last. It will not first become distorted, nor will the volume drop gradually. In this instance there is no indication that the trouble is a condenser or something else. If the set has a plate current meter it will read zero on the faulty amplifier. Circuit Similarity Glancing quickly at the tubes we wiU see that they are lighted, showing that the trouble is not a blown fuse. At the same time we will notice that the plates of the rectifiers are red hot. An over- heated plate means that there is an ab- normal current flowing in the plate cir- cuit, and a shorted filter condenser would cause such a condition. Looking at Figure 1 we see part of the wiring diagram of the 42-A amplifier. This portion of the 43-A is practically the same as in other makes ; in fact there are many amplifiers of different makes that have practically the same or very nearly the same wiring. Any amplifier and current supply can be divided as shqwn in Figure 2. There is one excep- tion, and that is when batteries are used. Even then it is sometimes required that filters be used, but usually for a dif- ferent purpose. The dotted lines in Figure 1 divide the apparatus of the 42-A amplifier into three divisions. In the amplifier there is actually no division of parts, nor are they partitioned off. The dotted lines serve only to show the similarity of each section to corresponding sections in other amplifiers, as is shown in Figure 4, which is part of the wiring of one type of RCA amplifier. Tube Current Check While the components in any or all three of the divisions may vary in differ- ent amplifiers, they perform the saine functions and are subject to the same trouble which can be diagnosed in the same manner. The filter may have one, two, or three banks of condensers ; it may have one or more chokes. In some cases there is also a voltage divider, which really forms a fourth division, but this unit need not concern us here. [7] When no meter is present in the plate circuit we must ascertain if cur- rent is getting to the tubes by some other method, such as a voltmeter hooked from the plate to the filament terminals of the socket. If the plates of the amplifier tubes are red hot, it is sufficient indica- tion that there is a flow of cur- rent and that the condensers are not shorted, for it they were, the current could not get as far as the amplifier tubes. This can be seen in Figure 1 and in Figure 4. When one of the filter condensers is shorted, the current flows from the recti- fier filament through the plus wire on the left, up to whichever condenser is shorted, then back to the negative wire, to the high voltage transformer, and so back to the plates and the filaments of the rectifier tubes. It cannot get up to the amplifier tubes. When the condenser becomes only "partially shorted" the action is different There is not a steady flow of current through the punctured spot, but instead the current flows intermittently. This can be seen by observing the plate cur- rent meter, which will be jumping back and forth quite rapidly. The sound will have dropped to a low level and will be very distorted, sounding fuzzy and whiskery, somewhat like a person with a very hoarse throat. When the meter is seen to act as de- INTERNATIONAL PROJECTIONIST June 1932 305 Filter Condensers AMfTiJ Vim 250 f 250 Bleeder Resistance Filter Condensers __/VvVVVV\_ FILTER RECTIFIER uUmmflMfiJ looooooppJ FIGURE 1 FIGURE 4 Fig. 1 shows the wiring of part of a W. E. amplifier; Fig. 4 shows the wiring of the corresponding parts of an RCA amplifier. Since there are but slight differ- ences between those two equipments, the trouble testing and remedial m.easurei are the same for both. The only difference in the rectifier is the positive lead: In Fig. 1 it is connected to the central tap of the filament transformer ; in Fig. 4 it is connected to one end of the winding. Fig. 1 has a choke in the positive leg; in Fig. 4 this choke is in the negative leg. RCA outfits have a bleeder re- sistance across the output of the B supply. In the amplifier proper, W. E. has another choke and a meter in the plate circuit. scribed in the above paragraph, it is nearly positive proof that a filter con- denser is punctured; no time need be wasted looking for trouble elsewhere. We must determine which is the defective condenser. Condenser Arrangement Figure 3 shows the arrangement of the condensers in the 43-A amplifier, and also shows the wires connecting them to the choke, LI in Figure 1. Wire No. 1 corresponds to the wire marked No. 1 in Figure 1. Wire No. 2 is also the same in both drawings. The negative wire. No. 3 in Figure 1, has not been included in Figure 3. To locate the faulty condenser, break wire No. 1 where it is soldered to the first condenser, thereby cutting out all 9 condensers connected in the circuit at this point. Wire No. 2 could have been unsoldered just as well. This would have cut out the 9 condensers to the right. After the wire has been discon- nectid, bend it so that it does not touch anything, then turn on the amplifier to see if the trouble has been cleared. Assuming that the meter now shows normal plate current we know that the shorted condenser is in this group. Turn off the amplifier again and break wire No. 3 at Y. Reconnect wire No. 1 and try the set again. If everjrthing is normal, it shows that one of the con- densers marked X is shorted, since these four were cut out when No. 3 wire was broken. Leave them out of the circuit and start the show. After the perform- ance a little further testing will show just which condenser is shorted; and it should then be replaced by another and the wiring re-connected as it was in the first place. Should the trouble still exist after No. 3 wire has been opened, then open wire No. 4, also at point Y, leaving No. 3 dis- connected. Turn on the set. Supposing that this cleared the trouble, we know that one of the three condensers in the center row is bad. Solder the loose ends of Nos. 3 and 4 together, but do not solder them to the condenser. This Left: Figure 2 Right: Figure 3 leaves the three center condensers out of the circuit but again puts the condensers marked X back in. Start the show and replace the bad condenser immediately after the show. If the trouble had still been present v/ith wires 3 and 4 disconnected, it would have indicated that one of the two top condensers was bad. Leave No. 4 wire loose, reconnect No. 3 at Y and also bring No. 1 over and connect it at Y. You may have to splice a wire onto the No. 1 wire to make it reach point Y. The procedure outlined above will locate the trouble and get the show go- ing again in the shortest time possible. It can be done in as short a period of time as it would take to disconnect the 43-A and to connect the output of the 42-A to the 200-A panel. Should it happen that the "short" is still present after removing No. 1 wire ai; the start of the test, the trouble is in the group at the right. Reconnect wire No. 1 and then disconnect No. 5 at Z. Ill is not necessary to break lead No. 2, since we already are quite certain that the trouble is in this group. Now continue the test in a man- ner similar to that outlined for the group of condensers at the left. In the event that the trouble still exists after wires No. 1 and No. 2 have both been disconnected, it shows that the plus wire in Figure 1 or some of the parts connected to it are grounded. In the case of a system having three or more banks of filter condensers, they must all be disconnected before it can be decided that some other portion of the equipment is grounded. If your amplifier is of a different type, it would be a good idea to look over the wiring to see what the most rapid method of repair would be. The wires could be marked with small price tags numbered 1, 2, 3, etc. The numbers would show the order in which the various wires should be disconnected in testing. In Figure 3 the group to the left would be numbered 1, 2, 3. The group to the right would also be numbered 1, 2, 3. If there were a third bank of condensers, they would also be numbered starting at 1 and continuing. Of course, the num- bering would be carried on beyond 3 if the wiring were such that more than three of them had to be removed to locate the faulty condenser. #1 ^ RECTiriER FILTER AITPLIFIER 31st I. A, CONVENTION AT COLUMBUS Election of officers and change in permit system are salient features of meeting. No change in officers. Press reports of conflict false. Strong attack on permit system James J. Finn ELECTION of officers, particularly to the Presidency, which hereto- fore has been almost a perfunctory affair, and consideration of and action on what has come to be known as the "per- mit system" featured the International Alliance Convention held in Columbus, Ohio, June 6 to 9. The Convention registered the largest number of delegates in the history of the Alliance — 824 delegates from 665 local unions being accredited by the Creden- tials Committee. Thirty-one locals were not represented at the time the report was read. Unfair Press Reports If ever any convention was subjected to unfair treatment by the press — both public and trade — that convention was the I. A. gathering in Columbus. Papers within the motion picture industry have long been known to garble news relat- ing to the I. A., and in some instances even to go out of their way to misrepre- sent the facts of certain happenings throughout the year. But it was some surprise to read in the public press highly colored statements of "gangster activi- ties" in and about the Convention, the asking for police protection by Conven- tion officials, the necessity for a "strong armed guard" about the Convention hall, and the "terrific conflict" which was be- ing waged by opposing forces at Con- vention meetings. Columbus papers ap- peared to be the sponsors of this distor- tion of the facts, a portion of which was released to all newspapers over national press association wires. It can be said at this time that none of the foregoing quotations from the pub- lic or trade press is true. While it is only natural that in an organization like the Alliance there should exist certain differences of opinion as to policies which would be reflected in vigorous verbal at- tack and counter-attack on the conven- tion floor, the Columbus I. A. Convention might well serve as a model not only for labor organizations but for all large or- ganizations having a national member- ship. There were no "gangster activities," no appeals for police protection, no "strong armed guards" about the Convention hall and, as it appeared to this writer, the sessions were distinguished by a surpris- ing air of placidity. All Officers Re-Elected The table accompanying this article sIjows that the entire pre-convention slate of officers, with one exception, was re- elected. The exception was the election of R. E. Morris as International Trustee in place of Walter S. Croft. All other office-holders were returned for another term. Contests for all offices were con- ducted in an eminently fair fashion and strictly on the merits of the individual contestants. Distribution of unsigned literature at- tctcking S'am Kaplan, President of the New York City Local 306, by his local opponents, and the appearance on the streets of Columbus of two trucks bear- ing placards which emphasized the sa- lient points contained in the pamphlets, were the only disturbing notes. Obvious- ly a New York local matter, these oc- curences were merely incident to and not a part of the Convention. Local Autonomy An important feature of the President's Report was the re-statement of the policy of the General Office to confer on local unions full authority, under the grant of local autonomy, to negotiate for terms and conditions. Another pronouncement as to policy stated that two-man sound projection shifts were deemed necessary, and any local union affecting a reduction in manpower did so at its own risk and expense. Various other important matters were discussed in the report. Consideration for and cooperation with the stagehand was requested of projectionists' locals. Terms and conditions of the new Road Scale agreement, effective to September [9] President William C. Elliott Cincinnati, Ohio General Sec-Treas. Fred J. Dempsey Boston, Mass. 1st Vice-Pres. John P. Nick St. Ijouis, Missouri 2nd Vice-Pres. William P. Covert Toronto, Canada 3rd Vice-Pres. William J. Harrer Ardmore, Penna. 4th Vice-Pres. Joseph C. Campbell Oklahoma City, Okla. Sth Vice-Pres. William T. Madigan Minneapolis, Minn. 6th Vice-Pres. Floyd M. Billingsley San Francisco, Calif. 1th Vice-Pres. Harland Holmden Cleveland, Ohio Trustees William C. Scanlan R. E. Morris John McCarroll A. F. L. Delegates William H. Clendening James F. Burke Delegate to Dominion T. and L. Congress William B. AUen 1, 1933, were promulgated. The strict necessity for observance of the I. A. rule that all amplifying equipment employ a card man was stressed. Efforts to secure legislation compelling two-man sound projection shifts were commended and the recommendation made that renewed vigor go into such work. Internal dissension in local unions was condemned as conducive to destroying the morale of the Alliance as well as of the local union involved. All local unions were urged to observe the recom- mendation of the Cleveland Convention that a reserve defense fund be estab- lished. High praise was paid the West Coast studio locals for their fine work in connection with the renewal of the Basic {Please turn to page 11) 10 INTERNATIONAL PROJECTIONIST June 1932 Cantyeniian Arranyewncnts Cawnwnittee WALTER WRIGHT Sec.-Treas. Local No. 386 Committee Secretary GEORGE LINGO Business Agent Local No. 12 LARRY BUCK President of Local No. 12 Advisory Chairman CHAS. E. PRATT Local No. 12 Convention Chairman HERBERT SCHELL Sec.-Treas. Local No. 12 Committee Treasurer EVERETT JAMES Vice-President Local No. 386 HARRY COLEMAN President Local No. 386 iita June 1932 INTERNATIONAL PROJECTIONIST 11 Studio Agreement, effective until March 14, 1934. Prominence was given to the present status of the jurisdictional differences now existent between the I. A. and the I. B. E. W. Certain units of the Alliance, notably those on the West Coast, experi- ence no little difficulty as a result of these differences. It was stated in the Presi- dent's Report that the experience of I. A. men in show business was a valuable asset in the campaign to keep this work within the Alliance. Responsibility of local unions to wage intensive combat against dual organiza- tions was emphasized. It was pointed out that dual unions, if permitted to grow strong locally, would eventually reach out and seek to add more and more terri- tory. The "Permit System" was ' de- scribed as the main source of supply for dual unions. To the American Federation of Musi- cians went the thanks of the Alliance membership for efficient cooperation in many trying situations. 'Permit System Action Probably the most important work of the Convention was to effect a change in the "Permit System", so named because of the custom of some local unions to issue a working permit to men who, while not, card holders, are bound by the rules of the local and must contribute to its support. This topic was not confined to the sub- mission of resolutions, of which there were many, but was brought right to the Convention floor and provided the basis for the sole "contest" of the sessions. Opposition to the "Permit System" was pronounced among stagehand locals and the smaller projectionist locals, the con- tention being that card-men applying for work at the larger locals invariably were discriminated against in favor of the non- member permit man. The action taken by the Convention provides that in future a per capita pay- ment on all permit men must be made to the General Office and in the same amount as for a card-man. The effect of this action will probably be to lend im- petus to the movement which has been gaining favor for sometime now, and that the establishment of "apprentice men" or "junior members" of the locals in order to distinguish the card-men. Allegations of discrimination in New York City against the card man from outside the city in favor of the man work- ing under permit were made by J. Bren- nan of Local 1. A reply to this charge was made by Sam Kaplan, who as President of Local 306 has conducted the work of providing a supply of men for sound jobs. Kaplan contended that the "Per- mit System" was the result of necessity and not of choice. Further, he contended, stagehands now were displaying interest in projection work that should have been apparent when appeals for added man- power were made four or more years ago. Another interesting phase of the Con- vention was the reinstatement of Charles C Shay as a member of Local 1, New York City. Shay, a former President of the Alliance, was stricken from the Alli- ance rolls at the Cincinnati Convention in 1924. Messrs. Dunn and Donnelly, ex- pelled members of Minneapolis Local 13, were also reinstated in the Alliance. Education Ignored Anyone who expected that the Colum- bus Convention would interest itself in the educational activities of the various local unions was doomed to disappoint- ment. Not one resolution was offered, not one speech was made in favor of official I. A. approval to the furtherance of a national educational society among projectionist locals. Moreover, not one word was uttered bearing on the desir- ability of the various locals participating in any educational activities for their own members. One technical session was held throughout the entire Convention week, and to St. Louis Local Union 143 must go the credit for providing the quarters and aiding in the holding of this single session. But then, St. Louis always did have superior projectionists. The desire of the friends of educa- tional for a pronouncement by the Con- vention in favor of such activities is readily understandable. It is understood by the friends of education that any movement looking toward the establish- ment of a national educational society must necessarily have the approval of the Alliance — without which it would be use- less to make much effort toward the establishment of such a society. The Convention did go on record, how- ever, as favoring the repeal of the Eighteenth Amendment to the Constitu- tion of the U. S. Splendid Arrangements The members of the two Columbus local unions are deserving of the highest praise for the manner in which they made arrangements and conducted Convention matters in general — and this despite their very meager resources. Hard work and lots of it went into the 31st Convention arrangements, and locals 12 and 386 have earned the appreciation of the entire Alliance for the way they handled the job. International Projectionist is glad of the opportunity to reproduce elsewhere in this issue a page of photos of the men who did all this work. Opening day was marked by the usual number of addresses by distinguished visitors, notable among which were the talks given by Governor White of Ohio and Rabbi Jacob Tarshish. The latter made a stirring appeal for a wider dis- tribution of the country's wealth, par- ticularly among the laboring class which cieates the wealth, and discussed the re- lationship existing between the Church and Labor. Special W. C. Representative In future the West Coast studio locals will have the benefit of an International Representative who will handle studio work exclusively, according to a resolu- tion adopted by the Convention. The studio situation has proved a severe strain on the International President, and it was deemed better to have one repre- sentative devote his entire time to this work. Appointment has not yet been made to this post. A list of the delegates accredited to the Convention by the Credentials Com- mittee is appended hereto: Local City and State Delegates 1 New York, N. Y John F. Casey AI. Gardner Harold Williams Edward P. Gately Joseph L. Magnolia Harry A. Sheeran John C. McDowell Louis Yeager James J. Brennan Sam Goldfarb 2 Chicago, 111 Richard J. Green John McCloskey Arthur Morrison James T. Ryan Mark Morrison Larry Cassidy Frank C. Olsen George E. Browne 3 Pittsburgh, Pa Robert Ellison James N. McGrath, Jr. 4 Brooklyn, N. Y Linford Risley Richard Walsh Thomas Murtha Bernard Ryan 5 Cincinnati, Ohio Edmund Callahan Andy Bolan 6 St. Louis, Mo C. O. Newlin William Nick William Wiggins 7 Denver, Colo George W. Bray field Frank G. Lemaster 8 Philadelphia, Pa Michael J. Sweeney William Mooney George W. Peterson John J. Shanahan 9 Syracuse, N. Y Joseph Flaherty 10 Buffalo, N. Y William Burke Edward Burke 11 Boston, Mass James H. Duffy James J. O'Brien James Hayes Samuel E. Horton William F. O'Brien 12 Columbus, Ohio Herbert Schell Larry Buck 13 Minneapolis, Minn. . .Roy Weir Fred Ebert 14 Albany. N. Y John B. Sample 15 Seattle, Wash Earnest A. Clark 16 San Francisco, Calif. .Joseph Roberts George Ward 17 Louisville, Ky Phil Green berg Mike Joseph 18 Milwaukee, Wis R. A. Scheffing Jack Worner 19 Baltimore, Md David E. Crow Jerome E. Buckingham 20 St. Paul, Minn Joseph H. McHugh 21 Newark, N. J Arthur F. Post Thomas V. Green 22 Washington, D. C Daniel V. Peck George Donaldson 23 Providence, R. I Joseph A. Prew Fred W. Newcomb 24 Toledo, Ohio John J. Russell 25 Rochester, N. Y Ben Connolley Michael J. Mungovan 26 Grand Rapids, "Mich. .L. W. Leland 27 Cleveland. Ohio Manus McCaffery John Fitzgerald 28 Portland, Ore Don Dumas Charles M. Campbell 29 Troy, N. Y James Lemke 30 Indianapolis, Ind Carl Tangeman D. R. Barnecio 31 Kansas City, Mo Felix D. Snow Harry W. Moody 12 INTERNATIONAL PROJECTIONIST June 1932 Local City and State Delegates 32 Duluth, Minn J. P. Shanahan 33 Los Angeles, Calif J. J. Riley E. H. Neff S. B. Newman H. B. Gregg Carl G. Cooper 34 Springfield, Ohio Peter Gaughan 35 Saginaw, Mich Alex Wineki 36 Lowell, Mass 37 Hollywood, Calif Lew C. G. Blix James E. Shaw Leland S. Armstrong Harry Hodgins Joseph M. Donnelly Edward J. Heim Charles J. Ferguson Raymond C. Morris 38 Detroit, Mich Alexander K. Oear E. Clyde Adler Joseph T. Finnigan 39 New Orleans, La E. J. Mather James Dempsey 40 Sioux City, Iowa Franlc J. Colbert 41 Atlanta, Ga Cliff Clower 42 Omaha, Nebr Harry H. Bushey 43 St. Joseph, Mo Walter Hay 44 Paterson, N. J John J. Lawler 45 Newburgh, N. Y John LaMont James D. Tweed 46 Nashville, Tenn Walter A. Craddock 47 Pueblo, Colo Dan Rush 48 Akron, Ohio Frank M. Gruber 49 Terre Haute, Ind . . . . Carl E. Braun 50 Sacramento, Calif. . . .William Deegan 51 Houston, Tex H,arry L. Spencer 52 New York, N. Y John Flaherty Arthur Gerson John W. Murphy S. J. Scoppa Charles J. Maguire 53 Springfield, Mass Michael J. Casey Daniel A. Haggerty 54 Binghamton, N. Y. . .Floyd C. Merrill 55 I^anoke, Va E. B. Brown 56 IiKintreal, Canada. . . .F. W. Cooper 57 Fall River, Mass William A. Dillon 58 Toronto, Canada Alfred E. Jackson 59 Jersey City, N. J James A. Walsh John J. Walsh 60 Pensacola, Fla Henry Brown 61 Canton, Ohio Charles Schumacher 62 Colorado Spgs., Colo. .Louis Ziman 63 Winnipeg, Man., Can. Norman W. Code 64 Wheeling, W. Va Frank J. Carney Theodore Bowers 65 Galveston, Tex Ed. Pye 66 Dayton, Ohio Joseph W. Boulie 67 Des Moines, Iowa. . . . Sidney A. Searles 68 Scranton, Pa Lawrence J. Campbell 69 Memphis, Tenn David Rosenthal 70 Youngstown, Ohio. . . . fc-. J. Tinney 71 Newark, Ohio Richard A. Thompson 72 Norfolk, Va James W. Simmons 73 Lynn, Mass Harold Hunt 74 New Haven, Conn. . .John S. O'Connell Herman G. Hegewald 75 Peoria Pekin, 111 Fred G. McLinden 76 San Antonio, Tex. . . .Eddie Galan 77 Atlantic City, N. J. . .William H. Clendening 78 Birmingham, Ala E. J. Lother 79 Massillon, Ohio Ira E. Dietz 80 Elizabeth, N. J Golie B. Hagin 81 Tacoma, Wash Roscoe C. Swindells 82 Wilkes Barre, Pa John McGeady 83 North Adams, Mass. .James Henderson 84 Hartford, Conn R. K. Lewis H. F. Sweet 85 Davenport, la. Mo- fine, 111 Glade W. Norney 86 Fitchburg, Mass George Lester Greene 87 Richmond, Va W. D. Anderson 88 Waterbury, Conn .... John M. Fitzgerald 89 Holyoke, Mass James Kennedy 90 Stockton, Calif Henry DeWitt Colestock 91 Boise City, Idaho. . . .W. E. J. Rose 92 Montgomery, Ala. . . .Lilliard T. Farris 93 Spokane, Wash Chester R. Cook 94 Butte, Mont Joe Levesey 95 Ottawa, Canada Romeo R. Marcil 96 Worcester, Mass John C. Ryan John E. Hauser 97 Reading, Pa Frank Porter 98 Harrisburg, Pa. .... . .WiUiam S. McKay, Jr. 99 Salt Lake Citv, Utah. Oscar Phirman 100 Parkersburg, W. Va. .Charles W. Miller 101 Newcastle, Pa P. F. Miller 102 Evansville, Ind Edward J. Moskowitz 103 Dubuque, Iowa Thomas S. Smith 104 Zanesville. Ohio John E. Fluke 105 London, Canada P. W. Rehder 106 Marion, Ind Clarence V. Covalt 107 Oakland, Calif William Daul Frank C. Casey 108 Geneva, N. Y Gerald L. Fowler 109 Bridgeport, Conn. . . .William Belden 110 Chicago, 111 Thos. J. Reynolds Thos. E. Maloy Hal Johnstone Benj. Hannaberg Jack Wolfberg Arthur Lyons John C. Mulvaney (Please turn to page 1.5) Convention Sidelights • Red Dowling of Easton, Penna., had the reddest hair of any Convention man. His partner, S. A. S'eifert,. had the low- est golf score — indoors! • Sands, of Los Angeles L.U. 150, didn't have a chance to ballyhoo California sun- shine. The first two days of the Con- vention had "official" mercury readings of 95 and 100. • Some of the West Coast camermen brought along their midget cameras, and some mighty fine pictures resulted — views of the buildings, of the parks, of Ohio State University (and of the St. Louis projectionists' headquarters). • Incidentally, the palm for the best all- around open house and a superior brand of hospitality must go to St. Louis L.U. 143. Starting well in advance of the Convention, the 143 boys kept everlast- ingly at it to the end. A fine bunch. Messrs. Kleintopf and Stone gave advice at the critical moments. • In the same breath we hasten to un- load the news that it was in the 143 quar- ters that the only technical (that is, strictly technical), session of the Con- vention was held. Dr. Brown, of erpi; P. A. McGuire, of the P.A.C., and one or two lesser lights expounded before an awed group of novitiates. Oscar Kleintopf, m.c. • Hurd and Klafiki of 659 ( W.C. camera- men), didn't seem to be having a good time. Evidently too busy running from Conference No. 38 to No. 39. •Thad Barrows, President of 182 (Bos- ton), and chief factotem of the P.A.C., was a visitor in Columbus while the Convention was in progress. • Billingsley, San Francisco L.U. 162, appointed an LA. v.p. last year, had his first taste of running a committee assign- ment. Everybody agreed he made a smooth job of it and bit his initials into the I. A. • The 4th District threw so many meet- ings that Lawrence Katz decided to re- main in bed and hold them in his room. • The 306 (N. Y. City) delegation put on the mystery act. Between Convention sessions nobody saw much of them — although it is safe to say that plenty of people heard from them. • They still continue to read the official list of delegates. This job requires about 2 hours fiat. Somebody ought to move that the printed list be thrown at the delegate and a request made for correc- tions, if any. • Those first day's speeches were simply terrible. Rabbi Tarshish had rather an effective mode of delivery, else even his remarks would have rated zero. Dick Greene, of L.U. 2, made a "hello" talk that should be officially adopted as a model. • Yager, of Salt Lake City L.U. 250, had more dope on various interesting angles of running a labor organization in the face of stiff opposition than have any three Internationals in the country. Good stuff, too. • Jim Shaughnessy and Arthur Martens, of 650 (Westchester County, N. Y.), shadowed each other continually. They didn't get a chance to put in a plug for Westchester real estate. These two men have done a whale of a job with 650; and they added to their reps in Colum- bus. • Joe Engle, prexy of 640 (Long Island), gulped down a ton of informa- tion without once committing himself. He probably got the most out of the Convention. • When that LA. bunch finally cleared out of the Neil House the management might just as well have taken a few sticks of dynamite and blown up what was left. • The smart boys who checked into the Deshler-Wallick were probably more sen- sible than the fellows at the Neil — yet they practically missed the Convention. • The oratory on the Convention floor anent the "permit system" was confined to the representatives from one town. New York hogged the show in this re- spect. • These newspaper reports about "gun- men" and "armed guards" were made to look foolish when on election day the contestants for office were seen disport- ing themselves at the rear of the hall, One expected them to play leap-frog next or call for a set of quoits. • Bill Kunzmann and Don MacRae were very much in evidence. Kunzmann was so busy crabbing about the merits of National carbons that several times he was left at the table talking to himself — and with the checks, of course. • Harland Holmden and Victor Welman were the Cleveland L.U. 160 big-wigs present — probably offering up thanks that it wasn't Cleveland tbat had to do the honors for the mob. • A Kansas delegate who came to the Convention suffering from an infected leg was suddenly rushed to the hospital for an emergency operation. The news was passed about the Convention hall on election day (with not more than a quar- ter of the delegates present), and $400 popped into a hat so fast that one would think it grew there. These LA. guys are given to long speeches — but they always pay off! • It was a close race for the best- dressed man prize between Madigan of Minneapolis and Maloy of Chicago. De- cision reserved until both contestants, submit to an inspection in pajamas. • So many members of Pittsburgh L.U. 171 were in attendance that one expected Mellon to be nominated. Brown, Free- man, Shawkey, Dietrich, and Criswell were spotted at various time.s. • Kalkoff of Milwaukee L.U. 164 had a speech prepared advocating the return of Schlitz beer. He tore up the speech after one tour of inspection. MOTION PICTURES IN RELIEF ik THE projection of motion pictures in relief, visible to a group of observ- ers occupying a wide range of positions with respect to the screen, but demanding no special spectacles or other apparatus at the eyes, has been experi- mentally realized in the Bell Telephone Laboratories according to disclosures made recently before the National Academy of Sciences by Dr. H. E. Ives. This extension of Dr. Ives' three-dimen- sional work from still pictures to mo- tion does not employ the conventional celluloid film, but harks back to a toy which the older generation will remember in which a series of pictures are mounted on a revolving wheel. Although the action lasts only a couple of seconds be- fore it repeats, the spectator sees a true motion picture which has all the depth and roundness of a stereoscope view. The cumbersome wheel is thus far essen- tial because of the high degree of ac- curacy of position needed to project the picture on a special screen, and serves to emphasize Dr. Ives' caution that com- merical application seems remote. Basic Principles To understand his latest development, one must first recall that seeing anything stereoscopically means that one sees it with each eye from a different viewpoint. The brain then interprets the slight dif- ferences in the two retinal images as meaning that the scene has depth. In the familiar parlor stereoscope, each eye sees a different photograph, the pair hav- ing been taken initially through cameras about three inches apart. If motion pictures are taken in a simi- lar manner, and viewed in such a way that each eye sees only the picture meant for it, there will be an illusion of depth in the picture. So far, the successful methods of doing this have involved the projection of the pictures alternately or in two complementary colors for the two eyes, and either a rotating shutter in front of each person or a pair of spec- tacles, colored red and green, to prevent the eyes seeing any but the appropriate picture. Dr. Ives' developments break away from using anything on or near the beholder; apparatus ends at the screen. The Screen The screen is one of the basic ele- ments of the system. It is made up of vertical celluloid rods, about a quarter- inch wide, and ground to accurate cylindrical curvature at front and rear. The curvature of the front face of each rod is such that rays of light starting fiom an elemental segment of the rear Probably the most important contributions to the art of three-dimensional motion pictures have been made by Dr. H. E. Ives of the Bell Telephone Laboratories. Recently Dr. Ives compiled a gargantuan paper which set forth in detail the results of several years of work in the art. Out- side of filling space, there appears to be no good reason why such detail should appear herein; and it is considered that the following concise article, prepared at, and appear- ing herein through the courtesy of. Bell Laboratories will best serve the interests of our readers. — Editor face are refracted in a narrow parallel beam toward the observer. By impressing successive elements of the picture, in the form of vertical lines, 01! the back of successive rods, the whole picture is built up for the observer. The picture on each successive element of a rod is refracted in a slightly differ- ent direction, so that the two eyes of each observer will see different pictures, as built up by two different series of picture elements. Since these two pictures are appropriate for left and right eyes re- spectively, a stereoscopic image is seen. To place the picture elements on the rear surface of the rods, the latter are given a frosted finish, and a lantern slide is projected on them. Making this slide is, however, a difficult proposition. Plurality of Views Since the ultimate spectators, if there be any considerable number of them, will probably be spread over an angle of thirty degrees on each side of the audi- torium, or a total angle of sixty degrees, the original picture has to be made from a series of view points extending over an arc of sixty degrees around the object. One way to do this would be to take a series of pictures, either successively by a single camera, or simultaneously by a group of cameras arranged along the arc of a circle and pointing toward the ob- ject at that circle's center. These schemes are, however, cumbersome and expensive. It is desirable to make the pictures v/ith apparatus employing a single photo- graphic exposure. In order to accom- plish this. Dr. Ives had recourse to a con- cave mirror four feet in diameter. Light rays from the object placed at the focus of the mirror would be reflected back to a focus at their origin, were it not for a semi-transparent plane mirror which re- flects them off at right angles. At the new focus of the mirror which has been thus established, a group of images of the object are formed, one for every pos- sible viewpoint around the concave mir- ror. These images are superposed, but it is possible to disentangle them, since the rays which form each one differ in the direction from which they approach the focal plane. The discrimination between images is effected by interposing a glass screen of fine concave grooves. This breaks up each image into a series of lines spaced regularly across a photo- graphic plate. In the space between adjacent strips of one view appears, in order, a strip from each other view, so that if one eye of the observer could see but one family of strips, it would perceive the picture Projector and screen devel- oped . by . Dr. Ives for show- ing motion pic- tures in relief. The wheel car- ries 32 succes- sive pictures which make up Dr. Ives' brief 'movie'. Behind it in the other wheel is th-? aperture ivhich admits a flash of light as each picture reaches the projectio/i point [13] 14 INTERNATIONAL PROJECTIONIST June 1932 'SOUND SCHOOL' MAIL FRAUD IMPRISONS TWO Federal Court sentences F. A. Jewell to 3 years and L. A. Smith to 2 years in Atlanta prison. Many I. A. victims. Internationed Projectionist exposed trio James J. Finn IN a courtroom packed with former "pupils" (victims), Fred A. Jewell, conductor of a "projectionist sound school" in Easton, Penna., and two co- workers, Lester A. Smith and Eric E. Mackey, were sentenced on June 20 in New York by Federal Judge Patterson for using the mails to defraud. Jewell was sentenced to 3 years and Smith to 2 years in Atlanta Penitentiary. Mackey also received a 2-year sentence, operation of which was suspended during good behavior. In addition, fines of $1,000 each were levied, but suspended, against the Electrical Sound Institute, parent company; the National Sound Service Bureau, Inc., and the Photo-Elec- tric Research Laboratory, Inc. The activities of Jewell were first brought to the attention of the writer three years ago by Easton Local Union 203, to the members of which credit is due for uncovering his fraudulent inten- tions. Since that time the writer has hammered away consistently against the activities of Jewell and many others of his kind — with Jewell's trail finally lead- ing him to the penitentiary. 'Students' Victimized During these three years Jewell vic- timized thousands of "students" who were induced to pay exorbitant "tuition rates" for a meagre amount of information, much of which was incorrect. So many Alliance members were duped by Jewell that former President William F. Cana- vana, at the instigation of the writer, issued a general ban against him throughout the Alliance. Offers of high- salaried positions upon "qualification" invariably were included in all the Jewell advertising matter. At one time Jewell offered the writer a "cut" on all students secured for his school through his sponsorship and back- ing. This offer being declined in what Jewell termed was "abusive language," the writer was threatened with a suit for defamation of character. Finding the organized projectionist field closed to his school, Jewell estab- lished headquarters in New York and became the head of three companies: Electrical Sound Institute (the "school") ; National Sound Service Bu- reau (the job outlet for "qualified stu- dents" ) , and the Photo-Electric Research Laboratory — the latter being sponsor for the "truly amazing" invention named the "Photo-Graver" which was reputed to make line cuts by a photo-electric proc- ess. This invention was proven a fake by the writer who cited references dated 1884 bearing on a similar process. The Chain During the life of this three-company set-up, more than 2,000 men, many of them practically destitute, enrolled for the course. The idea was sold to the victims in a most highly colored fashion, the promoters holding out that the Photo- Graver would soon establish a world monopoly and net huge returns to all concerned. More than 40 branches were established in as many cities all over the country and high-pressure salesmen were engaged to secure students on a 50 per cent commission basis. A sample of the type of promotion literature put out by this combine is appended to this article and is indica- tive of the tactics employed by this group. To make their offer doubly at- tiactive, assurances were given of a tie- up with a major sound equipment manu- facturer which would enable placement of hundreds of "graduates" of the school. Other Schools Operating Thus ends the story of Mr. Jewell and his associates. But the story of sound as viewed from one point on the concave mirror as though seen through a grille of thin vertical wires. Precisely this effect is achieved by making a lantern slide from the plate and projecting it upon the back of the rod screen de- scribed in an earlier paragraph. Two Separate Views It will now be understood why each eye of the ultimate beholder sees a dif- ferent picture, the difference being that of beholding the original scene from two viewpoints a few inches apart. Stereo- scope vision is thus attained, and those who have seen Dr. Ives' laboratory set- up have reported that the effect of depth is well marked. To make a motion picture, it is neces- sary to project successively varying pic- tures on the screen. It will be appre- ciated that the minute accuracy neces- sary to register a fine structure of lines exactly upon a series of rods can only be secured by glass plates firmly but ad- justably mounted on a rigid moving sup- port. Dr. Ives therefore affixed his series of 32 transparencies to a rotating disc so that each plate could be separately orien- tated in the optical system. Since the pictures do not halt in the projection gate, it was necessary to flash a light through each as it reached the projection point. All in all, the size and delicacy of the apparatus emphasize Dr. Ives' caution as to the remoteness of commercial applica- tion while the lifelike quality of the mov- ing image is convincing evidence that an- other milestone has been passed in the development of motion picture relief. The projected re- lief pictures as viewed from ttiree directions w w M ■1 ■ ■ ■■^^■i IPIIBHIIIII Ht'" """ " '' !•' ^imi^^^^^^l m^^^ jtn^SMtHtiL! i } JK \f k^HHHHi ■^^yyi I'^'rlij E I ^ \ '¥ "T*?! ■1 1 l^nbl .....i II i' l| , '^H WKm^i 1 E^ 1 1 m^^ June 1932 INTERNATIONAL PROJECTIONIST 15 Sample of ^Bait' Used by Jewell Associates There are going to be more ten and fifteen and twenty and twenty-five thousand — yes — and even fifty thousand dollar a year jobs with our asso- ciated corporations, than there are warts on a frog's er - rear end, and some of you fellows who are reading this now, are going to be in these jobs. All of you who are reading it have a chance top of it and we have got it by the tai for them. We have been and are going to continue to grow faster than any other corporation in Amer- ica. We are going to get so doggone big and have so damn much money that the United States Gov- ernment is going to have to build new mints, and we are going to have to open up our own banks just to have a place to keep the money — the ones they have now are not big enough. No matter how wild a dreamer you are, or how vivid your imagination is, or how many shots in the arm you can take, you can't realize what a chance you have here. Our, big jobs are going to be filled from the ranks of the men holding the little ones now, and if you are anything more than the dumbest guy in the world, you want to get sold on that idea and then go out and sell the world on it — for the world is our meat and we are sitting on So get your coat off — give us every ounce of "guts," brains and energy that you have, and if you can find any place that you can use them that will bring you bigger, quicker returns, I am a cock- eyed hump-backed Chinaman. So let's go — let's hit that old ball — let's triple the pace and boy, oh boy, we will start believing in Santa Claus again — we will begin to pity Rockefeller's pov- erty and you'll know that God is in his old Heaven and there are more blessings there than there are brickbats in hell — so altogether now^ — HEADS UP CHIN OUT FORWARD HO— WE'RE OFF!! projection schools is not ended. Even now there are sound projection schools in operation all over the country. The "courses" offered embrace a wide range of prices and instruction — from "10 Easy Lessons for $25" to courses of six months and more for $150. Many such schools operate within the law, but their services are pretty much of the same unsatisfactory pattern. In- struction sponsored by the Local Union has been demonstrated to afford the best service and greatest protection to mem- bers of the organized craft. International Projectionist derives particular satisfaction from the Jewell conviction, inasmuch as it exclusively brought to the attention of the craft the fraudulent activities of this three-com- pany combine and lent its services in opposing its operations. CONVENTION DELEGATES (Continued from page 12) Ltical City and State Delegates Ul Lawrence, Mass Maurice A. Fitzgerald •.V2 Oklahoma City, Okla.John B. Campbell lis Erie, Pa Terrence Cunningham 114 Portland, Me Frank J. Jackman 115 Jacksonville, Fla Ralph M. Toy 116 Trenton, N. J Stephen J. Connelly 117 BelHngham, Wash. . . .Albert W. Bostrom 118 Vancouver, Canada.. .Harry Pearson 119 Auburn, N. Y James J. Gallery 120 Pittston, Pa Norman J. Saunders 121 Niagara Falls, N. Y.. .William H. Colquhoun 122 San Diego, Calif Carl B. Callahan 123 East Liverpool, Ohio. .William Hemphill 124 Joliet, 111 William G. Brown 125 Bay City, Mich Walter R. Richardson 126 Fort Worth, Texas . . . Linton W. Burke 127 Dallas, Tex H. W. Flovd 128 Utica, N. Y Donald R. Rood 129 Hamilton, Canada... .Earl Jack 130 Altoona, Pa Charles E. Brunner 131 New Bedford. Mass . . 132 Warren, Ohio Clarence W. Otto 133 Hammond, Ind William J. Schulte 134 San Jose, Calif John F. Faull 135 Sedalia. Mo Earl E. McMillin 136 Hamilton. Ohio Neal Johnson 137 Springfield. Mo Joe Roberts 13S Springheld. Ill William A. Schafer 139 Schenectady, N. Y . . . Harrv A. Engle 140 Chattanooga. Tenn. ..R. H. Mills 141 LaCrosse, Wise Paul Spettel 142 Mobile. Ala R. E. Morris 143 St. Louis, Mo Oscar Kleintopf A. L. Stone 144 Memphis, Tenn William H. Holland 145 Lakewood, N. J Richard S. Harrison 146 Fort Wavne, Ind Bud Berger 147 East St. Louis, 111. . . .Clyde A. Weston 148 Logansport. Ind D. H. DeHaven 149 Brockton, Mass John H. Kenny 150 Los Angeles, Calif. . . .F. A. Sawyer T. W. Armentrout R. L. Haywood C. C. Harden M. J. Sands E. W. Apperson 151 Lincoln, Nebr Malcolm F. Dewey 152 Hazelton, Pa George A. Gicking 153 El Paso, Tex Komer F. Bowington 154 Seattle, Wash James McNabb Charles Crickmore 155 Piqua, Ohio Joel W. Hixson 156 Danville, 111 Georger Hamer 157 Allentown, Pa Stanley M. Moyer 1.58 Fresno, Calif E. J. Knobloch 159 Portland, Ore J. S. Haughey J. T. Moore 160 Cleveland, Ohio Victor A. Welman Jacob Fried Charles S. Bullock 161 McKeesport, Pa Louis McMillian 162 San Francisco, Calif. .Anthony L. Noriega James Luther 163 Louisville, Ky Robert L. Hulett Edward W. Klapheke 164 Milwaukee, Wis Glen C. Kalkhoff Elmer A. Klase 165 Cincinnati, Ohio Harry Schwartz William Hahn {Continued on page 26) 'RAIN' IS FIRST W.E. WIDE RANGE RECORDING "Rain," which is now being produced at the West Coast by United Artists, is the first talking picture to use the new Western Electric Wide Range Recording. The advantage of this new recording sys- tem in extending the frequency range of sounds that can be recorded and re- prciduced are specially evident in the exterior scenes of this story which are being filmed at Catalina Island. During the steady downpour of rain, an essential part of the story's atmos- phere, the moving coil microphone dem- onstrated its superiority, and the ability of wide range to record sounds with greater naturalness and increased free- dom from distortion has facilitated the task of obtaining faithful recording in several difficult shots of the production, particularly in the constant dripping of the rain, and in the recording of sound in a narrow corridor scene where a floor ceiling and two walls made intelligible audition difficult. In both instances excel- lent results have been obtained. Wide Range Advantages ' ^ The essential changes in Wide Range Recording consists in the use of moving coil microphones to the exclusion of all other types and in the introduction of three simple electrical networks which re- sult in flattening the over-all frequency characteristics from the output of the microphone to the input of the scanning slit in reproducing. The highest order of fidelity is obtained up to approximate- ly 8,000 cycles, an increase at the high end of more than half an octave over previous recording limits. P. A. C. Welcomes Hausner in Miam,i ^C TANISLAUS HAUSNER, Polish-American, and member of Local 306 of *^ the International Alliance, who was rescued in mid-Atlantic after his plane failed him on a projected flight to Warsaw, arrived in Miami, Florida, on June 23. Despite a late arrival, thousands of Miamians were at City Yacht Basin and the Olympia Theatre to greet him. At the Olympia repre- sentatives of various organizations extended their greetings and felicitations and the Gold Cross of Merit was presented. The welcoming ceremonies, par- ticipated in by a representative of Governor Doyle E. Carlton, Mayor R. B. Gautier, Thaddeus Zazulinski, First Secretary of the Polish Legation, and others, were held at the Municipal Airport. Speaking briefly from the Olympia stage, Hausner, while declining to tell of the days on the floating plane, said he was in the air 28 hours before his plane failed and estimated he covered 2,890 miles. W. S. Roberts, regional Vice-President of the Projection Advisory Council, read from the stage the following telegram to Hausner: ON BEHALF OF WILLIAM C. ELLIOTT PRESIDENT OF INTERNATIONAL ALLIANCE OF THEATRICAL STAGE EMPLOYEES AND MOTION PICTURE MACHINE OPERATORS OF THE UNITED STATES AND CANADA AND THAD. C. BARROWS PRESIDENT OF THE PROJECTION ADVISORY COUNCIL EXTEND CORDIAL WELCOME HOME AND EXPRESS ADMIRA- TION FOR YOUR ENTERPRISE COURAGE AND ABILITY WHICH RE- FLECTS CREDIT ON ALL PROJECTIONISTS WE KNOW YOU WILL TRY AGAIN AND ARE CONFIDENT YOU WILL SUCCEED - P. A. McGuiRE, Executive Vice-President, Projection Advisory Council. PRACTICAL PROBLEMS OF THE PROJECTIONIST NO method has heretofore been made available which would per- mit the testing of the idle pro- jector for output level while performance was being conducted on a second pro- jector. In the event that a difference in output level between projectors de- veloped, it was necessary to wait until the end of the day's run before checking and correcting trouble of this nature. Meanwhile, the projectionist was obliged to compensate for inequality of sound level between projectors each time a change-over was made. As a result of this procedure, faulty control of sound volume occurred in a great many cases. The Committee realizes that some means should be provided which would permit this inequality of volume output to be corrected immediately after being discovered, and would also enable a check to be made at any time that the existence of this trouble is suspected. A brief description of a device for this purpose follows: Output Level Indicator The general wiring of the output level indicator circuit is illustrated in Figure 1, which shows a jack A bridged across the output of one projector A, while a jack B is bridged across projector B. This arrangement can be extended to include three or more projectors. At- tached to the output indicator is a plug to be inserted in the several jacks and also a plug to be connected to 110- volt A. C. circuit. Figure 2 gives the details of wiring of a vacuum tube voltmeter and an asso- ciated amplifier. At the left is shown the power transformer and rectifier tube and filter. For use with the output indicator, the Committee recommends that several lengths of test film carrying 1,000-cycle, 90 per cent modulated sound track be furnished to each projection room as a part of the regular equipment, to be kept Harry Rubin 'T'HE accompanying article is based on the report of the Projecdon Practice Committee to the recent Spring Meeting of the S.M.P.E. The report is divided into four sections one of which, "Theatre Problems of the Release Print," was presented as a separate paper at the Theatre Operation Sessions of the meeting. The sections are: 1. A description of a method of testing the output level of several projectors during the performance for the purpose of maintainiing them in an equalized condition. 2. A description of a method of checking the continuity of the speech circuits of individual speaker units during the performance. Such an arrangement can also be used for equalizing the sound volume before each performance. 3. A study of "Theatre Problems of the Release Print" contained in a paper that deals with: Processing of Film Buckled Film Dense Positive Prints Uniform Volume Level Film Cutting for Change- The S.R.P. over Purposes 4. The Committee's comments on projection problems and on the importance of competent supervision of projection, dealing with the inain- tenance of quality of performance and the effecting of economies in operation. Committee members: Harry Rubin, Chairman J. O. Baker Thad Barrows ( G. C. Edwards Sam Glauber J. H. Goldberg Chauncey Greene Herbert Griffin Jesse J. Hopkins on hand at all times. These lengths can conveniently be attached to the begin- nings or the ends of the reels or run separately on the idle projector, thus affording a check on the output whenever desired during the performance. Speech Circuit Check With regard to the second question mentioned above, a method is desired of determining the continuity of the speech circuit of each individual horn receiver during the performance. The speech coil in certain types of loudspeakers is a deli- cate piece of equipment and is subject to occasional breaking down ; and when this occurs, the distribution of sound in the theatre may be noticeably affected. This condition requires immediate correction. A device, such as is shown in Figure 3, may be used to provide the projection- ist with a ready means of determining which of several loudspeakers is inoper- ative owing to a defective speech coil. Each speech coil circuit is provided with a jack placed in one side of the line between the output of the horn panel and the loudspeakers backstage. This per- mits plugging an A. C. milliameter in series with each speaker. A zero reading [16] W. C. Kunzmann R. H. McCullough P. A. McGuire Rudolph Miehling F. H. Richardson Max Ruben P'. T. Sheridan L. M. Townsend on the meter indicates an open circuit. This equipment can also be used to check the equalization of projectors by plugging the A. C. milliameter into one of the speech coil circuits, and running the 1,000-cycle test film in each projector while noting the meter deflection. Screen Visibility There are several factors which adv- versely affect screen and sound results. At the present time the projectionist has a far less critical view of the screen than anyone else in the theatre. He should be provided with facilities to enable him to see the picture as plainly as the pa- trons in favorable locations so that he can discover and remedy visual defects and not be dependent upon observations made by others. The projectionist should be able to hear the reproduced sound as plainly as anyone in the audi- ence. Assistance in the solution of the problem of improving the projectionist's reception of reproduced sound in the theatre is urgently requested. Any prac- tical ideas along this line will be grate- fully received and carefully studied by the Committee. These problems naturally present tech- June 1932 INTERNATIONAL PROJECTIONIST 17 Figure 3 n'cal and commercial difficulties but are sufficiently important to merit intensive study for the purpose of improving pres- ent conditions, which impose a severe handicap upon projectionists in the pre- sentation of sound pictures. In the in- terim, before high quality sound can be provided in the projection room, volume indicating instruments should be fur- nished as a partial substitute. The Committee has received the co- conditions and in a flawless manner, as the projected picture and sound are the closest contacts the public has with the industry. This is best accomplished through supervision by qualified men who have familiarized themselves with the many projection problems through years of theatre contacts. Supervision includes instructions to projectionists as to the proper presenta- tion of the productions ; the proper hand- operation of one manufacturer, who is Ung of the film in order to reduce dam- attempting to improve the visibility of the screen from the projection room. As a temporary measure, the Committee ad- vocates the use of a high-powered glass so as to bring the screen apparently with- in twenty feet of the projection room. Projection Supervision The Committee wishes at this time to stress particularly the need of competent supervision of projection. This need has existed since the first pictures were shown, but its importance has been underestimated. Competent supervision is even more vital to the industry under present con- ditions. There has never been a time when the "sales resistance" of the public has been as great as at the present, or a time when its critical faculties were so highly developed. It is doubly important, under such circumstances, that enter- tainment be presented upon the screens of the theatres under the most favorable age and degree of wear of prints and thus to extend their useful life; the in- stitution of working routines to provide for smoothest performance; the provision of instructions relating to the uses of equipment to obtain various projection effects for the purpose of enhancing the entertainment value of the performance; provision for periodic inspection of pro- jection equipment, including the check- ing for proper adjustments, so as to pre- vent film damage; making correction of possible sources of trouble before break- down occurs with consequent possible in- terruption of show; and the training of projectionists to acquaint #iem with methods of handling emergency situa- Q i=a= ^ O Q COt/TWL INDlCf\TOfK o VOLUME CONTROL tions, instructions for quickly locating any source of trouble and the methods of making repairs. Supervisor s Advantages The supervisor is in close contact with practical projection problems in the thea- tres and is able to seek out remedies for the correction of difficulties encountered, and to initiate or aid in the development of new appliances to this end or to ac- complish improved or more economical operation. He is also able to pass upon the necessity of making repairs, and is often able to point out a more economical method of making them. He is familiar with the methods of testing under practical operating condi- tions the many appliances offered to the theatres. He is frequently able to sug- gest methods of improving such devices, making them more valuable to the theatre. As an example of the need of super- vision, a recent court decision ordered an exhibitor to pay more than $200 damages to a film exchange for injuring a print while in the possession of the theatre. The amount awarded was based upon the actual footage that was scratched at the rate of 3%c per foot. It is quite prob- able that such a decision might lead to similar actions against exhibitors in the future. Even when exhibitors are not ordered to make direct payment to exchanges, the industry is obliged to absorb the cost of all film damaged through mishandling, most of which could be prevented. The Committee directs attention to the fact that many large companies have in the past few years enormously improved projection and sound results in their theatres by providing competent super- vision. Supervision of projection pro- vides the only means by which economy and high quality results can be effected. Lack of proper supervision in projec- tion has already accounted for a sub- stantial loss of money to the industry, and this waste will continue until the importance of competent supervision is realized. K <^=!5> OUTPUT FIGURE 2 Oy.put indicator for use on A.C. power supplies FIGURE 1 Outline drawing of theatre equipment, showing the use of an output indicator for equalizing the outputs of two or more projectors. 18 INTERNATIONAL PROJECTIONIST June 1932 THEATRE PROBLEMS OF THE RELEASE PRINT This paper was prepared by the Projec- tion Practice Committee of the S.M.P.E. and was originally intended to form a portion of the Committee's report to the Spring Convention. It was deemed advisable, hoivever, to present this par- ticular section at the special Release Print Session in order that it might have the benefit of consideration and discus- sion along with related problems of the production and distribution branches of the industry. THE problems of the release print as they affect the theatre, although comparatively few, are nevertheless of the utmost importance in attaining a high degree of excellence in screen re- sults. The Projection Practice Committee has, in its previous reports, called atten- tion to the shortcomings of the various methods of treating finished positive prints to facilitate transit of film through the projector under ordinary projection conditions. The Committee has also di- rected attention to the problems of film buckling, film mutilation, the responsi- bility of the projectionist in handling prints and the responsibility of the thea- tre manager in reporting faulty prints. Film Processing In respect to the problem of processing film, the Committee has found that some of the methods employed were not en- tirely satisfactory, inasmuch as in some instances emulsion continued to accumu- late on projector parts during the early showings of the film, and in other in- stances the preparations used in the processing methods accumulated in the projector and caused faulty sound. From practical experience and tests, the Projection Practice Committee has found it undesirable to apply even minute amounts of wax or oil preparations to the film, and has also found that the use of unprocessed film is undesirable. The Committee advises against the foregoing methods; but is in favor of a process whereby the emulsion is hardened suffi- ciently to avoid the difficulties en- countered in early projection of film. Such a process has now been in use for the past several months by certain pro- ducers and has been found entirely satis- factory. Buckled Film Buckling film prevents proper visual and sound presentation. This problem v/as a serious one until very recently when complaints of this nature became less frequent. Apparently some improve- ment has been made in the film or in the laboratory methods which accounts for the elimination of these difficulties. The Committee recommends that a con- stant check be maintained on this point in order that the present improved prod- uct may be continued. Prints are sometimes received in thea- tres which are printed too densely for best results. This may have been caused by the density of the print having been judged in a studio where it was projected on the screen, the illumination of which was in excess of that which can be ob- tained in the average theatre. On the other hand, prints are occasionally re- ceived which are too light in density, causing a lack of proper contrast. The Projection Practice Committee is at the present time taking readings of illumination screens in various theatres and it is hoped that a recommended level for screen illumination can thus be ar- rived at and the studios requested to de- termine best print density under such conditions. Occasionally, it is impossible to make proper visual and sound change-over be- tween reels, due to the fact that the sound essential to the action continues up to the last frame of the outgoing reel and begins with the first frame of the in- coming reel. Due to the displacement of the sound track in relation to the corre- sponding picture, such cutting of film re- sults in loss of or confusion in sound. The Committee recommends that, in determining the beginnings and endings of reels, a point be selected for change- over which will be satisfactory from a visual and sound standpoint, and further recommends that suitable leeway be al- lowed so that sound essential to action should not occur at the extreme end or the beginning of a reel. Uniform Volume Level At the present time theatres frequently receive film with widely varying level of recorded sound within single reels, a greater variation between reels of the same picture and still wider variation between subjects. Under such conditions if is difficult to maintain the proper sound level in the theatres. Since the theatres are continually striving to main- tain their several projectors and their sound equipment in an equalized con- dition for presentation of sound pictures at the proper level, it is highly desirable that the producers and laboratories co- operate in providing film which is free from wide variations in recorded sound level which are not intentional. The objects of the Standard Release Print are to reduce film mutilation, which occurred through the punching of film by individual projectionists for change-over purposes, and also to permit accurate change-overs between reels. To be prop- erly effective, it is necessary, first, that the indicating marks for motor starting and film change-over be accurately placed, both with respect to end of reel and with respect to individual picture fiame; second, the indicating marks should be sufficiently conspicuous to be conveniently noticed by projectionists. This second point is made for the rea- son that in a good many instances a black spot without the surrounding white circles appears upon a dark background. This seriously reduces the visibility of the indicating marks when viewed from the projection room and thus contributes to uncertainty of the projectionists in starting motor and in making film change-over. It would be better to have a white circle surrounding the black spot. The Committee feels that only by rendering the indicating marks reliable in one hundred per cent of the cases can the element of uncertainty be removed and the punching of film by individual projectionists be eliminated. The Committee is of the opinion that the new reduced size of the indicating marks is an improvement over the origi- nal size, and where this present size of black mark is applied on a light back- ground, the reduction in size has not affected the visibility. [Note: One suggestion as to a means for overcoming this lack of visibility is tc apply a narrow concentric ring of opaque material around each indicating mark on the negative film. This would result in a narrow white circle around each black dot on the positive print, which indication should be visible against a dark background. This ring might be stamped on with the same operation as that now performed in punching the negative.] Projection Practice Committee,. Harry Rubin, Chairman. Editor's Note: Another improvement in the S.R.P. has been suggested by several readers of International Projection- ist. This has to do with the placing of the signal dot in such a way that it ap- pears on a character in the picture who is moving from right to left in the scene. When the signal dot is so positioned, the- eyes of the projectionist instinctively fol- low the movement of the character and ignore the dot — often ivith serious trouble ensuing. It has been suggested that when the proper positioning of the dot would place it directly upon a character in motion, it be moved either higher or lower so as to appear on the stationary set background. A TRIBUTE WELL EARNED JUST how important is the work of the Projection Practice Committee to the S. M. P. E. and to the indus- try generally is evidenced by the ac- companying letter received from Dr. A. ISI. Goldsmith, President of the Society. Even more significant is the fact that a large majority of the members of this Committee are Alliance men, and their fine work for the Society cannot help but win prestige for the entire Alliance with- in the Society and throughout the industry. It is pretty generally agreed that the work of the Projection Practice Commit- tee within the past year represents the finest contribution on practical projec- tion work made to Society records in the past ten years. Dr. Goldsmith's letter itself bears out the truth of this estimate. It is to be regretted, however, that so few realize the splendid work done by projectionist members of the S'. M. P. E. and only an extremely limited number have the faintest understanding of the sacrifices made by members of this Com- mittee. A prophet is not without honor save in his own country; and a hard- working projectionist member of the S. M. P. E. Projection Practice Commit- tee gains recognition and earns the thanks of all save those members of his own craft, most of whom apparently are too busy with other things to care much about the matter. "• The high regard of- Dr. Goldsmith for the work of this particular Com- mittee is evidenced by the fact that he was a regular :< attendant at all of its meetings. The Committee meet- ings usually were called to order about 7:30 P. M., and it was frequently after midnight before ad- journment. Throughout the sessions various sub- jects were brought up for consideration and debate and no action was taken or decision made which was to be incorporated in the report without pains- taking thought and full discussion. The notes of each meeting were care- fully gone over by Jesse Hopkins, Committee sec- retary, so that typewrit- ten reports of each ses- sion could be sent out to each member prior to the drafting of a final report. It should be borne in mind that this work by projectionist members was in addition to their regular daily work. No extra compensation was received for this arduous toil and no cheering multitudes were expected to be on hand at the read- ing of the final report. These men worked for their craft and for every member thereof. How many projection- ists ever took the time to think about the sacrifices ef these men whose efforts meant better work and increased pres- tige? Not many, it is safe to say. The work and responsibility of this Committee was assumed almost entirely by Harry Rubin, the Chairman, and Jesse Hopkins, the Secretary. This is not said in any sense to discredit the other mem- bers of the Committee, all of whom would be glad to substantiate this statement. Projectionists derive great benefit from the work of the men who comprise this Committee and other progressive projec- tionists who are interested in the ad- vancement of their craft. It is to be sincerely hoped that the projectionists v/ho are prevented from joining in or- ganization activities of an educational nature will at least be willing to give others credit for what they accomplish absolutely without any financial com- Officm Society of Motion Picture Engineers Board of Governors GENERAL OFFICE June 2nd, 1932. Mr. James J. Finn, James J. Finn Publishing Corp., 1 Best 47th St., Nen Jfork City. Dear ^ir. Finn: Permit me to compliment you on the excellent material contained in the May, 1932 issue of "International Projectionist" relative to the activities of the Society of Motion Picture Engineers. I particiilarly appreciated the comments made on page 5 under the heading of "Monthily Chat". As I said on the occasion of the Convention, the Society is proud of its projectionist membership, regards this group of members as a most valuable asset, and leans heavily on them for information and practical guidance in matters involving their craft. The Projection Practice Committee is one of the most active Committees of the Society and has, as you have correctly pointed out, contributed substantially to the ad- vancement of the art. I hope that thp Society may continue to enjoy the help of the projectionists so that the engineers may be kept well informed relative to practical problems of theatre operation. Sincerely yours. pensation and frequently without any re- ward. Fortunately for the craft, there are such men who are willing to make the sacrifices which result in the col- lection of accurate technical information which may be passed along to all mem- bers of the craft. International Projectionist stands squarely back of the idea that the dif- ference between an "operator" and a projectionist lies solely in the difference between the indifferent individual and the man who is willing to do his bit toward raising the general level of projection work. We repeat: anything that adds prestige to the craft as a whole is of benefit to the individual member thereof. Only by being ever ready to con- tribute to the general craft welfare can the projectionist hope to gain recogni- tion from fair-minded executives. No commercial organization, no mat- ter how powerful it may become, can con- tinue indefinitely to lower the quality of its merchandise and increase the price. We say with equal positiveness that pro- jectionists, as a whole, must make the same effort to maintain the quality of their work. The value of organization is freely acknowledged, but every crafts- man must endeavor to render a service to those who employ him which ivill reflect credit upon the organziation to which he belongs. These projectionist members of the Projec- tion Practice Committee, through their unselfish- ness, through their sense of responsibility to the or- ganization to which they belong and in their desire to raise the standards of their profession and help their fellow-craftsmen — these men, who sought neither money nor cheers, should serve as a shining example of the type of craftsman wanted in the projection field. No scroll will be struck off to pay honor to these men for their work, no extra coins will jingle in their pockets as a result thereof. But — they will feel amply repaid, we are sure, if the general level of projection work has been raised through their efforts. After all, if not this, then for what else did they have to work? [19] RECTIFIER POWER SUPPLY FOR SOUND SYSTEMS B. F. W. Heyer and W. F. Bonner THE low voltage D.C. power re- quired for operation of sound re- producing equipment varies with the equipment but, generally speaking, in a typical theatre installation it is neces- sary to have a 12-volt source supplying approximately 8 amperes for the 2 ex- citer lamps, 41/2 to 12 amperes for the loudspeaker fields, and in those systems having amplifiers using filament type cathodes, filament current must be sup- plied. Some systems require, in addi- tion, several amperes for the pilot lights, relays and announcing system. Thus, from 10 to 25 amperes at ap- proximately 12 volts represents the low voltage power demand of the usual sound system which must be supplied from rec- tifier power units when applied to present installations as battery replacements and to new installations as a primary source of low voltage current. The first major consideration in the design of a rectifier power supply unit is the supression of the A.C. component to rectified current. To arrive at the ripple voltage requirements, the follow- ing factors must be considered: Amplifier Gain The gain of the amplifiers must be considered because the hum introduced in the photoelectric cell and amplifier from excessive ripple voltage in the ex- citer lamp will be increased in the same proportion as the reproduced speech. In making the tests to determine the allow- Rectifier power supply units, to replace storage batteries, are now available, through ERPI, for all Western Electric sound systems. First public announcement of this new unit was made at the S-M.P.E. Spring meeting through the medium of the accompanying paper. able ripple voltage in the exciter lamp circuit, it will be noticed that the pres- ence of film in the projector reduces the hum originating in the exciter lamp. However, the hum introduced from the exciter lamp will always be fixed with reference to the sound introduced by the sound track on the film, and for that reason it is preferable when determining ripple voltage limits for the exciter lamp to make these tests without film in the aperture. In systems having amplifier tubes with filament type cathodes which must be supplied from the power unit, the hum introduced in the photoelectric cell ampli- fier will be constant but will be increased with the reproduced signal in direct pro- fiS • • Q P S 20 0 >■ 16 a ' D E K"' < N 0^^ -^ ^BULH RI 1 RECTIF raOLATIO ft lER N C TO I C TO I ) 97i. : 93^. ~ ' ~7 — ^ D ->__ E ^DRY RE DISC RE :gulatio It CTIFIER N C TO I C TO I ) 89^. : 855^. • ■ L 2 S 4 5 6 7 8 AMPERES D.C. LOAD REOHLATION CURVES OF RECTIFIERS portion. In addition, where filament cur- rent is used for C bias, the ripple volt-v, age in the filament supply will directly excite the grids. This necessitates a fila- ment current extremely free from ripple, if annoying hum is to be kept out of the system. The hum introduced in an amplifier* being supplied with filament current from the power unit where the amplifier is located in the system after the volume control, will be introduced in the system as a constant level for all gain settings. In determining, therefore, whether a certain ripple voltage in the exciter lamp and the amplifier filament circuits is satis- factory, it is advisable to increase the gain in the system until the loudspeaker is being energized at a maximum, with no film in the aperture. Having established a satisfactory hum to signal level ratio by the original test on one loudspeaker, this permissible voltage can then be applied to the sys- tem, regardless of the number of speak- ers operating; although the volume of the sound will be increased to meet the requirements of a larger auditorium, the amplitude of the hum on the system will not increase appreciably with relation to the signal. Response of the System at 120 Cycles Should the sound system have a rela- tively low response at 120 cycles, it must be taken into consideration at the time the power unit is being designed, as, otherwise, future modifications, either in the amplifiers or loudspeakers which will improve the response, may also raise the hum to an objectionable level. The effect of system noise introduced by the photo-electric cell and amplifier tubes >vas very considerably masked with the earlier types of film recording, as the noise inherent in the recording itself was relatively high. This ground noise also has a masking effect on hum introduced in the system through the ripple voltage from a power supply unit. This must be considered at the time the tests are made to decide the ripple voltage limits, for in the event that these amplifier and photo- electric cell noises are subsequently re- duced through improvements in the sys- Figure 1 * Referred to as "System Amplifier" through- out this article. [20] June 1932 INTERNATIONAL PROJECTIONIST 21 jrr* ■ ■ FIGURE 2 Output voltage control resist- ances of a rec- ti f ier power supply unit tern, a hum previously completely masked may become annoying during the quiet sequences of the film. Accumulative Effect of Ripple Voltage in System The accumulative effect of ripple volt- age from the components of the system must also be considered in the design of a power unit. For example, while a hum originating in the exciter lamp, amplifier or loudspeaker may be below audibility when considered separately, the hum in each of these components may be addi- tive, and therefore may reach an unde- sirable value. This necessitates keeping the allowable ripple voltage for each cir- cuit below that actually necessary so the hum in the system will still be within the noise to signal ratio considered satis- factory for operation on present-day sound systems. The circuits operating the signal lights and relays in sound systems designed for battery operation are usually so wired that unfiltered direct current cannot be applied to them without introducing hum in the system. For that reason it has been found necessary to filter this circuit not only to prevent inductive interference with the sound system but also to pre- vent chatter of relay armatures. Load Regulation The second major design consideration i-3 load regulation. By load regulation of a rectifier power supply unit is meant the effect on voltage supplied to any part of the sound system of load changes made either purposely or accidentally on other parts of the system operating from the same power supply source. This prob- lem is practically non-existent Avith a lead storage battery since the terminal voltage variations over the current range required in sound reproducing equip- ment is so slight that it can be neglected. However, both rectifier and filter cir- cuits have certain regulation character- istics giving rise to voltage variations under load changes that must be given careful consideration. For example, in actual operation the exciter lamp is fre- quently turned on or off. thus changing the load on the system by approximately Trrr 4 amperes. When this takes place, it must not interfere with the satisfactory operation of the other parts of the system operating from the same power supply. To determine the permissible limits of such load changes, it is necessary to con- sider the circuits of all the sound sys- tems with which rectifier power supply is to be used. In some cases, minor changes in switching or circuits must be made to adapt the system to the load regulation characteristics of the power supply unit. Where such modifications are deemed inadvisable from an engineer- ing, operating, or economic standpoint, the power unit must be designed to meet llie requirements of the sound system. Unless a careful analysis is first made of all systems with which the power unit is to be used, it is impossible to design a unit that can safely be put in the field v/ith the assurance that it will give the service expected. To determine load regulation char- acteristics of a rectifier power supply unit, it is necessary first to determine the toad regulation of the rectifier to be used, and then that of the filter required. Fig. 1 shows load regulation curves of the two main types of rectifiers, bulb and dry disc. These curves were made with the rectifiers connected for full-wave rectification. A dry disc rectifier, due to its regula- tion characteristics, is not satisfactory for parallel operation of filters. Separate rectifiers and filters must be provided tor each load circuit in order to obtain the required regulation. An alternative method can be employed, this consisting of relays and substitute load resistances. Due to the inherently good regulation characteristics of the bulb rectifier, in practically all cases it is not necessary to compensate for the possibility of dis- connecting certain portions of the load from the filters, although in a few in- stances it may be desirable to use a compensating resistance and a relay. Output Voltage The third major design consideration is that of output voltage. There are naturally many more factors entering in- to the manufacture of a rectifier power supply unit which may result in a wider variation in output voltage than obtains with lead storage batteries. With proper design, these voltage variations may be restricted to narrower limits than a bat- tery of proper ampere-hour capacity, and as a consequence, require less attention from the projectionist for rheostat read- justment. Fig. 2 shows the output voltage con- tiol resistances of a rectifier power sup- ply unit having five separate filter cir- cuits. Readily adjustable tapped re- sistances are used rather than rheostats as proper adjustment may be made at the time of installation to bring the out- put voltage within the range of the equip- ment rheostats. The resistance of the filter system* should be kept as low as possible, as otherwise the change in D.C. resistance of the filters due to heating during oper- ation may be sufficient to cause a varia- tion in output voltage beyond the range of the equipment rheostats and will also necessitate constant readjustment while in operation. With proper design, re- adjustment need be made only once or twice during the first two hours and pos- sibly one more adjustment when the temperature reaches a constant value. Load Regulation Requirements of a Typical System Satisfactory load voltage regulation must be maintained to keep the correct volume level and to prevent burn-outs of vacuum tube filaments, overloading or distortion in the amplifiers. The most important point in the cir- cuit for proper maintenance of the volt- age is that at the exciter lamp. Any current change in the lamp, however slight, is greatly amplified in its effect on the volume level of the system. The FIGURE 5 Shotving a tivo-projector power unit mounted on a wall 22 INTERNATIONAL PROJECTIONIST June 1932 FIGURE 3 View of lower section showing shielding FIGURE 4 Inside view of 2-projector power unit showing reactances and relay voltage on the amplifier filaments, while ol less importance, must be maintained well within 5 per cent of normal voltage. Shielding In a grouping of rectifiers and filters in one case it is necessary to carefully consider inductive effects of the react- ances, both internal and external to the power unit. Obviously when any filter circuit in a power unit is connected or disconnected, a powerful field is created around the reactances. This may cause a disturbance either in other filter cir- cuits, or directly in the sound syslem amplifier circuits. To eliminate inter- ference all resistances must be shielded. Fig. 3 shows a method used in mount- ing and shielding the resistance of the amplifier filament and signal current sup- ply circuits, which eliminated all trouble- some inductive effects. The sound system will also be com- pletely free from clicks or disturbing noises when the output circuits of the filters are correctly wired for satisfac- torily low rectifier hum. Installation The power unit shown has been de- signed for wall mounting and is of mini- mum practical width and depth to make best advantage of the space available in or near the projection room. The large unit is divided into upper and lower sec- tions to facilitate mounting and handling within the theatre. As it is desirable to have the leads as short as possible, the best locations for the power unit is in the projection room. To this end all rectifier tubes are pro- tected against physical contact and the cutside temperatures of the cases meet the requirements for equipment in the room. It is often possible and practical when making replacement installations to locate the power units in the former location of the batteries or the battery charging panel, using the existing wires and add- ing only those wires necessitated by the modification. Where possible, it is de- sirable to locate the units in the projec- tion room, as the equipment is then cen- tralized and under constant observation of the projectionist, as well as leaving all space outside of the room available for other purposes. Combining Units To facilitate installation and to minimize wall space required, it is de- sirable to combine a number, of rectifier and filter circuits. Figs. 4 and 5 show a unit which includes circuits for two p.e.c. amplifiers with their exciting lamps, one system amplifier, three loudspeaking re- ceivers, and current for auxiliary circuits. PHILOSOPHIC BACKGROUND OF UNIONS Sumner H. Slichter, Ph.D. QUITE a large number of labor unions — the machinists' union, the electricians', the sheet metal workers', the boilermakers', the blacksmiths', the carmen's, the maintenance-of-way men's, the printing pressmen's, the photo-engravers', the textile workers', and the clothing workers' — have demonstrated not only their will- ingness to cooperate with managements in solving problems of operation, but their ability to make an important contribution. Needless to say, these organizations are not willing to cooperate on any terms and conditions. Naturally and properly they put the interests of their members ahead of the interests of the stockholders for whom they work. The fact remains, however, that ingenious and far-sighted leaders on both sides who possess the will to cooperate have succeeded in discovering a basis on which management and labor can join to promote the interests which they have in common. Cooperation or Bitter Class Struggle Whether or not the dominant note in American industrial relations during the next generation will be union-management cooperation or bitter class struggle depends upon the leaders in the industries which are now unorganized — iron and steel, automobile, electrical equipment, meat packing, rubber, telephone, petroleum, agricultural implements, and others — persist in their uncompromising opposition to the efforts of wage earners to join the other organized groups in the community. My prediction is that the policy of union-management cooperation will prevail, because I am confident that there is enough industrial statesmanship among American business men for them to realize that the policy of suppressing organiza- tion is the policy of sitting on the safety valve. June 1932 INTERNATIONAL PROJECTIONIST 23 NEW SYNCROFILM PORTABLE SOUND PROJECTOR AN- NOUNCED BY WEBER THE Syncrofilm Portable Sound Pro- jector was developed for profes- sional and non-professional use for all purposes where permanent equipment cannot be maintained. It is the result of many years of development work by en- gineers thoroughly qualified in the field of projection and film sound reproducing equipment, and is manufactured by Weber Machine Corp., of Rochester,, well known in the professional sound field. The Syncrofilm Projector was designed not only for the dual purpose of sound reproduction and projection performance of the highest class, but for simplicity in set-up, operation and transportation. It is a complete unit, incorporating all of the most desirable features known in both sound and projection. Attachments Unsatisfactory Through the rapid and unforseen growth of sound pictures, many manu- facturers were forced to face the prob- lem of re-designing and re-tooling their silent projectors or engineering an at- tachment to fit their product. Those familiar with sound reproduction will un- derstand the difficulty of designing satis- factory attachments of this nature. Prac- tically all of the silent type of portable projectors were designed for operation at 60 ft. per minute; while sound film requires a constant speed of 90 ft. per minute. It is necessary to maintain this speed to close limits without waver or fluctuation. Syncrofilm engineers were in the for- tunate position that they did not need to consider large inventories of parts and equipment which may be made obso- lete through any radical changes in de- sign. They were enabled to make a new start, thus availing themselves of all the latest developments in the art of pro- jection and sound. That they have taken advantage of this opportunity to its full extent will be quickly realized upon in- spection of this new equipment. All ProfesMonal Features The new Syncrofilm Portable Sound Projector incorporates many of the most desirable standard features embodied in professional projectors, and, at the same time, lightness and portability has been included. It is truly portable in every sense of the word, weighing only 60 lbs. The newest developments of Mazda pro- jection lamps have been adopted. The lamps used in Syncrofilm projectors equal the results obtained with carbon arcs, without the difficulty to maintain or the skill required to operate. The projection lenses used are of very high grade, manufactured by one of the lead- ing manufacturers of projection lens sys- tems. They are also interchangeable with standard lens systems, used in the- atre projection equipment. Latest Sound System The sound and amplification system proves that advantage was taken of the extensive experience Weber had in the NOTES from the SUPPLY FIELD * building of sound systems. The optical system is designed to reproduce the high- est frequencies recorded, every unit being set and tested to cut a minimum of 8,000 cycles. The Syncrofilm all electric amplifier is one of the latest developments in the art, combining all of the advantages of the new tubes and circuits available, making it possible to reproduce faith- fully the latest full-range recordings. Syncrofilm is a high grade sound projec- tor, up to date in every way, producing clear, steady pictures, and faithful reproduction of sound. Better projectors are not made, regardless of price, is the Syncrofilm claim. SPECIFICATIONS Case Suitcase type, cast aluminum, size 81/2" X 21" X 21". Black crackle fin- ^ ish. Weight Projector complete, 60 pounds. Frame Aluminum alloy machine moulded castings. Intermittent Hardened and ground, star wheel and cam, same size and design as used in popular theatre projectors, easily adjusted to take up wear. Light Mazda pre-focused base, 500-, 7.50-, or 1,000-watt, 500-watt furnished with standard euipment. Projection Lenses 4" Focal length of same type used in theatre equipment. Other sizes can be furnished, if desired. Reflector Ground and polished optical glass, heat-resistance coated. Condensor System Two 3" dia. ground and polished piano convex. Motor l/'20 h.p., 110- volt, 60-cycle constant speed, with highest grade precision balanced armature. Bearing Special alloy bearing bronze. Shutter Two-point rear shutter designed as partial fan to ventilate gate and aperture plate. Ventilation Fan attached to motor shaft, de- signed to furnish a large volume of air to cool projection lamp. Drives Round belts, which facilitates a slow even start and prevents excessive shock on mechanism and film. Sound Mechanism Is an integral part of the projector, designed to drive and operate in conjunction with projector mechan- ism. Parts Has fewer parts than any sound pro- jector developed up to the present time. Exciter Lamp Standard 8V2-volt, 4 ampere, bay- onet base. P. E. C. Standard U. X. Base, caesium type, of highest quality obtainable. Amplifier Push-pull pentode type incorporating latest and best features. Tubes: one 280, one 224. one 227 and two 247. Speaker Dynamic Cone Type, perfectly matched with amplifier. Current 110-volt, 60-cycle A.C. Aperture Recent standard for sound prints. Strippers All driven sprockets are provided with strippers. Framing Framing lever is easily accessible at back of case, and is positive in action. Lubrication A centralized lubrication system is provided so that all parts may easily be oiled from one point. Take-Up Easily adjusted, smooth in operation, cannot chatter or seize. 24 INTERNATIONAL PROJECTIONIST June 1932 NEWS and VIEWS A collection of random thoughts, and some not so random; fact, fancy and opinion pertaining to the projectionist and pro- jection matters. The free-for-all forum. SEVERAL unions, harrassed by com- petition, have rushed into print in defense of their organizations. Letters to the editor and paid display advertise- ments extolling the organized labor body are appearing with increasing frequency. That which we said in our October, 1931, issue still holds good: people don't want to buy the Union, but they are customers for that which the Union should repre- sent— quality work and safety guaranteed by a responsible organization. Newspapers seldom, if ever, attack a labor organization as such. They can't afford to, circulation figures being what they are. Usually the press rails against the direction of a labor body, and a so- called browbeaten minority is induced to bear testimony against their own brother members. The point of this item is that Unions should be particularly careful in dis- tinguishing the focal point of any attack by the press — whether it be against the organization (which seldom is the case), against the individual or the directing group. Naturally, advertising copy in- tended to offset unfavorable publicity should be based on the point or points at issue. Otherwise, advertising money is wasted. • The few copies of I. P. which go to France each month have already gotten in their deadly work. News Item: "Mo- tion picture machine operators here (Paris), have formed an organization known as the Association des Operateurs de Projection Sonore." Two organizers, please. • Magnascope (enlarged screen), is old stuff. Yet, this is the one projection "stunt" that always draws the "Ohs" and the "Ahs" from any audience. Perhaps the foremost exponent of Magnascope is Harry Rubin, of Publix Theatres. As these lines are written Rubin is employ- ing Magnascope in two Broadway thea- tres with marvelous results. One of the pictures, "The Doomed Batallion," is en- hanced in entertainment value by about 25 per cent (in our estimation), through clever employment of Magnascope. Great Care Necessary The use of Magnascope calls for the utmost discretion and faultless execu- tion. Sloppy use of the idea, or bad spotting within the feature, can do more harm than good. While we are on the subject, Rubin deserves much credit for the splendid special projection and effect work he employs to set off the Jesse Crawford organ presentations at the Paramount. When in New York don't' fail to catch some of this work. • Bausch & Lamb Optical Co. are sup- plying a zippy catalogue of their pro- jection lenses which contains valuable in- formation for the projectionist. The screen image table on p. 11 should be ignored in view of the new standard aperture dimensions. A note to 691 St. Paul St., Rochester, N. Y., will do the trick. • It probably isn't news any longer to many Alliance members, but we men- tion the resignation of William F. Cana- van as a member of the staff of Publix Theatres Corp. Future plans not an- nounced. NOW that the social season for Local Union parties is over, the truth can be told. We have numerous letters from projectionists which tend to prove that our estimation of organization affairs as strictly members' parties is correct. Evidently some of the boys have long had in mind the idea which we spilled herein recently — that such affairs have been "packed" with outsiders and that much harm resulted therefrom. We just can't help it if we have the power to read the boys' minds. • Our erstwhile "boy friends," Messrs. Fred A. Jewell and Lester A. Smith, who for the past three years have been in- terested in "educating" the projection- ist via Projectionist Sound Institute, of Easton, Penna. ; Electrical Sound Insti- tute, National Sound Service Bureau, Photo-Electric Research Laboratory and a few other Sound-this and Photo-thats, have just been convicted in New York Federal Court of using the mails to de- fraud. Our first foray against Jewell, et al, was three years ago, and we wound up our campaign against him in our November, 1931, issue. Then came the "'pinch." We don't know how much money we have saved members of the Alliance by our devotion to duty in this campaign, but certainly all locals should vote us a small donation apiece. On the right, please. Incidentally, Mr. Jewell (himself), who tried first to bribe us and finally to punch us, is now on his way to At- lanta— glorious spot. Merry Xmas, Mr. Jewell — covering all three years. IT doesn't require much neck-craning to discern the renewed interest in rear projection in this field. Most of the inquiries come from exhibitors who naturally are interested in the process because it appears to hold promise of a reduction in manpower. They're for it. Anyone who has watched the progress of the intimate newsreel theatres which Trans-Lux has spotted about the country will have noted a marked improvement in the quality of rear projection. There is nothing mysterious about rear pro- jection. Regular Simplex mechanisms are used (although it is rumored that Trans-Lux is building its own mechan- ism ) . The Trans-Lux screen is neither metal nor cloth; it has a gelatine base. The Trans-Lux Lens For years Trans-Lux has enjoyed a monopoly (through patent rights), on a special wide angle lens with prisms which gives a foot in picture area for every foot the projector is removed from the screen. Conversely, one could get a 2-foot picture at a 2-foot distance, a 5-foot picture at 5 feet, a 10-foot picture at 10 feet, etc. Considerable trouble was experienced with this lens at first (mostly a "lens spot" in which most of the available light would be concen- trated), but this difficulty has been overcome and even illumination is now obtained. It is doubtful if Trans-Lux will con- tinue to enjoy a monopoly in the rear projection field, as good screens for this work are now available and Bausch & Lomb has recently developed a lens which also gives a so-called 1-to-l effect. WARNING ! INTERNATIONAL PROJECTIONIST has no Subscription Agents ONE J. J. Farrell, representing himself to be an authorized sub- scription agent for INTERNATIONAL PROJECTIONIST has been operating in Eastern states — notably in New York, New Jersey and Connecticut. This man, and all others making similar claims, are fakes, irrespective of how many "authorizations" or "introduc- tions" they exhibit. LP. has no subscription agents, and all sub- scriptions should be made direct to the publisher. All readers, and particularly Local Union officials, are requested to be on the lookout for these fake agents and to report their whereabouts immediately to INTERNATIONAL PROJECTIONIST. juiw ^9•^?. INTERNATIONAL PROJECTIONIST 25 What does Television mean to You? fl. ERE is a new book that gives all the facts about this new and amazing offspring of radio. Avoiding technical terms it follows the development of television right up to date, explains principles, methods and apparatus, and weighs for you the problems, possibilities and probabilities of television as a commercial tool and a form of entertainment. Just Published TELEVISION by EDGAR H. FELIX Radio Consultant 276 pages, 5^x8, illustrated, $2.50 HAS television arrived at last? Can present broadcasting and receiving equipment be adapted to television? Will television of the future come by air or wire? This book from beginning to end was written expressly to supply reliable answers to these and hundreds of other questions you may have asked regarding television. With many explanatory illustrations and diagrams it gives a thorough background of technical facts — then makes plain their importance from the standpoint of the experimenter, the commercial operator, the broadcaster, the "listener-in." Order from INTERNATIONAL PROJECTIONIST Covers television such as: topics 1 Wesi 47th Street New York, N. Y. ^— lias Television really arrived? the HOW and WHY of Television. ^—unsolved problems of Television, ——possibilities of 100-Hne system, —latest syncbronizing methods, "—the human eye in Television. ^— will future programs come by air or wire? —new developments affecting receiver design, —future progress of Television. 24 experts explain sound" re cor ding and projection HERE is a book needed by every man connected with the practical side of the talking picture industry, in theatre or studio. Written by the men who taught the screen to talk it covers every phase, both technical and practical, of sound recording and reproduction. Recording Sound for Motion Pictures Published for the Academy of Motion Picture Arts and Sciences Edited by Lester Cowan 404 pages, 6x9, 229 illustrations, $5.00 Answers many questions on: — practical technique of recording — booms, blimps and microphones — recording systems — film laboratories — assembling the talking picture — reproducing systems —practice and problems of sound projection TWENTY-four sections, each written by a recognized authority and specialist in his field, present an authoritative description and ex- planation of the fundamental principles involved in recording and repiro- ducing sound for motion pictures and their practical application in the studio, on location and in the theatre. Everything essential or important is covered, from the fundamental nature of sound, down to the practical aspects of volume control, theatre acoustics, and other everyday problems of sound projection. Order from INTERNATIONAL 1 West 47th St. PROJECTIONIST New York, N. Y 26 . INTERNATIONAL PROJECTIONIST June 1932 CONVENTION DELEGATES 181 Baltimore, Md . Samuel Isaacson David Silverman 201 202 (Continued from page 15) 182 Boston, Mass . Thad C. Barrows 203 John H. Fullick 204 Local City and State Delegates 183 Beaumont, Tex James F. Burke . L. A. Beller 205 206 166 Gales burg. Ill . Mart J. Neylon 184 Porterville, Calif . Christa Muggleberg 207 167 Oshkosh, Wis . Roy Cleaveland 185 Spokane, Wash . C. S. Alderman 208 168 Victoria, Canada .... .Edward Abery 186 Springfield, Mass. . . .John F. Gatelee 209 169 Oakland, Calif .E. H. Bishop 187 South Bend, Ind. . . .William Richardson 210 Cleve Beck 188 Kalamazoo, Mich . . .Harold D. Wallace 211 170 Kansas City, Mo .Robert R. Dillon 189 Alliance, Ohio .Frank Reardon 212 Frank Dowd 190 Wichita, Kans .Joseph H. Crane 213 171 Pittsburgh, Pa . Ben Brown 191 Cedar Rapids, Iowa .Paul Hunter 214 R. C. Freeman 192 Findlay, Ohio . Charles Tisdale 215 C. A. Dietrich 193 Bloomington, 111. . . . Fred E. Shoup 216 172 Jackson, Mich . Earl Ramsey 194 Indianapolis, Ind . . . .Arthur W. Lyday 217 173 Toronto, Canada . Samuel Wells John O. Benner 218 Arthur Milligan 195 Manchester, N. H . . .Samuel F. Cooley 219 Charles A. Dentelbect 196 Salem, Mass . Benj. H. Chatel 174 Lafayette* Ind .Fred Browning 197 Knoxville, Tenn . . . ■ Gus Kelly 220 175 Tacoma, Wash .O. M. Jacobson 198 Bangor, Me .Albert E. Pierce 221 176 Joplin, Mo .John H. Rogers 199 Detroit, Mich ■ Gilbert E. Light 222 177 Connellsville, Pa. . . .Harry C.Wilson James P. Murtagh 223 178 Salisbury, N. C .C.J. Ritchie M. A. Hawkes 17<> Williamsport, Pa. . . .Joseph Engel Frank Kinsora 224 180 Everett, Wash .M. B. Hake 200 Norristown, Pa ... . . Edwin F. Bale Flint, Mich George S. Robertson Waterloo, Iowa James A. Seese Easton, Pa S. A. Seifert Little Rock, Ark E. H. Billingsley Austin, Tex Clyde J. Barr Topeka, Kans Fred W. Rausch Freeport, 111 William B. Jury Uniontown, Pa T. E. Lawson Carbondale, Pa AI John Farrell Edmonton, Alta., Can. Oliver Lynn Belleville, III John Keifer Calgary, Canada Ken S. Davidson Great Falls, Mont. . . .John H. Case Sandusky, Ohio George Ladd Bakersfield, Calif Harry W. Scribner Marys ville, Calif Joseph Apathy Rockford, 111 William Yalden Pottsville, Pa George H. Fey Minneapolis, Minn . . . Ray Gulleckson Charles R. Wells Sioux Falls, S. D Harry B. Manning Aurora, 111 Thomas E. Morrissette Shreveport, La John F. Elzey Providence, R. I Herbert F. Slater Edwin W. Anthony Washington, D. C DeForest L. Ormes Thomas A. Reed A imouneiiig f^omplete f or table I^OUIld and W ISUal Jr rojector $485.00 Complete With Amplifier and Speaker ^T^HE manufacturers of SYNCROFILM are pleased to announce a A complete Portable Sound-on-Film and Visual Projector for 35 mm. film incorporating all of the latest development in both sound and pro- jection, at a price within the reach of all. This projector features simpli- city of design, rear shutter, latest type 500- or 1,000-watt Mazda lamps, and straight line film travel. Easy to thread and easy to set up. All parts aluminum alloy castings and not stampings. WEBER 59 RUTTER STREET Prices f. o. h. Rochester, New York MACHIIVE CORPORATION ROCHESTER, NEW YORK Export Office: 15 Laight Street, New York Qty Cable Address: Romos, New York .. June 1932 INTERNATIONAL PROJECTIONIST 27 Local City and State Delegates 225 Atlanta, Ga William P. Raoul 226 Waco, Tex E. A. Harrell 227 Ponca City, Okla. . . .Arthur H. Erwin 228 Toledo, Ohio R. O. Sheats 229 Fort Collins, Colo. . . .Lloyd Seibert 230 Denver, Colo Edward A. Roegner 231 Grand Forks, N. D . . . Richard J. Treacy 232 Northampton, Mass. .James B. O'Neill 233 Buffalo, N. Y Bernard N. Pinzel Albert F. Ryde 234 Walla Walla, Wash. . . Frank E. Wright 235 Fond du Lac, Wis. . . William Rieder 236 Birmingham, Ala John P. Amberson 237 Racine, Wise John Chmelik 238 Muscatine, Iowa Arthur C. Arbogaat 239 Fairmont, W. Va W. C. Davis 240 Billings, Mont L. G. Denayer 241 Vallejo, Calif Ernest H. McNair 242 Pittsburg, Kans W. B. Ketterman 243 Asbury Park, N. J. . .James Greig 244 Newark, N. J Louis Kaufman Harry S. Oppenheimer 245 Lynn, Mass Leo F. Barber 246 Muskogee, Okla Mile Miller 247 Lancaster, Pa W. W. Reading 248 Dayton, Ohio W. W. Hofferbert 249 Dallas, Tex C. E. Rupard 250 Salt Lake City, Utah. George A. Yager 251 Madison, Wis Frank M. Rogers 252 Sacramento, Calif. . . .A. M. Davis 253 Rochester, N. Y Carl J. Redfern Calvin W. Bornkessel 254 Yakima, Wash Leonard B. Hinds 255 Helena, Mont August J. McDonald 256 Lawrence, Mass Joseph Bell 257 Ottawa, Canada William H. York 258 Cumberland, Md Ernest V. Wolford 259 Chattanooga, Tenn...J. B. Lowry 260 Lake Charles, La Sidney Schmidt 261 Salina, Kans C.E.Adams 262 Montreal, Canada W. Hoffman C. Arless 263 Richmond, I.nd Walter M. Jellison 264 Newport News, Va.. .Steven V. Haigler 265 Greens burg. Pa Harry W. McKnight 266 Jamestown, N. Y. , . .Charles Hemphill 267 Tiffin, Ohio Delbert J. Henninger 268 Alton, 111 Arthur Van Collie 269 Lawrence, Kans Phillipp M. Saunders 270 Clarksburg, W. Va. . .Dallas D. Cornell 271 Charleston, W. Va. . . E. F. Davis 272 Cortland, N. Y Robert C. Griffin 273 New Haven, Conn. . . Philip R. VanArsdale 274 Lansing, MSch John P. Fitzgerald 275 Pittsfield, Mass Clifford E. Williams 276 Urbana, Ohio 277 Bridgeport. Conn. . . .James V. Fensore 278 Asheville, N. C E. M. Harrell 279 Houston, Tex Edward J. Miller 280 Denison, Tex W. H. Russell 281 Paducah, Ky 282 Middletown, Ohio. . . . Ben Francis 283 York, Pa William J. Donsen 284 Wilmington, Dal Alfred M. Cole 285 Troy, N. Y Harry M. Brooks 286 Des Moines, Iowa. .. .George A. Hartnett 287 Beaver Falls, Pa Alix O. Denhart 288 East St. Louis, III. . . .Ray McNickle 289 Elmira, N. Y Tracy C. Mann 290 Gloversville, N. Y. . . . J. W. Newkirk 291 Grand Rapids, Mich. .Jack O. Bogardus 292 Muncie, Ind John Snell 293 New Orleans, La Arthur Chateau Willie Breitenmoser 294 Phoenix, Ariz Curtis Hayes 295 Regina, Canada H. O. Rennebohm 296 Warren, Pa Howard D. Putnam 297 San Diego, Calif Albert F. Stoll 298 Shreveport, La Tom Hasty 299 Winnipeg, Canada. . . . A. J. Wishart V. Armand 300 Saskatoon, Canada. . .John Wright 301 New Britain, Conn. . .George C. Dunigan 302 Calgary, Canada Duncan B. Mackenzie 303 Hamilton, Canada. . . . Fred Ward 304 Waterbury, Conn .... Frank J. Brown 305 Galveston, Tex Carl H. Mahlitz «06 New York, N. Y Sam Kaplan Abe Brenner Frederick E. Castle Isidore R. Cohn Frank R. Day Chas. F. Eichorn Max Feinberg James V. Lefante William Paster Edgar T. Stewart Jacob S. Winick Morris J. Wolheim 307 Philadelphia, Pa Abbott Oliver William Friedman Horace B. Johns Louis Krouse 308 Dunkirk, N. Y John Schmitz 309 Newport, R. I Edward Patrick 310 Atlantic City, N. J. . .Augustus Hilton 311 Middletown, N. Y. .. . 312 Enid, Okla Herbert G. Creekmore 313 Amsterdam, N. Y. . . .William Green 314 Schenectady, N. Y. . .John T. Sauerborn 315 Steubenville, Ohio. . . .T. P. Caniff 316 Miami, Fla George E. Raywood 317 Waukegan, 111 Benj. R. McMahon 318 Lockport, N. Y Edward A. Baes 319 Mansfield, Ohio Russell Lutz 320 Savannah, Ga M. H. Addie SUPER INTENSITY AUTOMATIC PROJECTION LAMP H. C. 10 Super Intensity Lamp The Lamp With Accurate Arc Regulation and Arc Focusing by Means of the Heat From the Arc Itself H, C. 10 Features: . Self-Starting . Self-Focusing . Independent Negative Feed Regulation . Magnetic Stabilization . Better Arc . Self -Lubricating Bearings . Weston Ammeter . Carbon Indicator . Forced Air Cooling . Correctly Shaped Hood . No Feed Rollers . Full 22-inch Trim Descriptive booklet on request. Write for it to HALL & CONNOLLY, Inc. 24 Vandam St., New York, N. Y. 28 INTERNATIONAL PROJECTIONIST June 1932 Hat?c your screen re-surfaced MR. PROJECTIONIST by the Schacht Process When you have your projection screen resurfaced by the Schacht Process — the only absolutely dependable method — ^you get a guar- antee of Clarity of Outline, Original Newness, Lasting Quality Hundreds of exhibitors have taken advantage of this economical method of improving projection — to the satis- faction of the progressive projectionist. . . . Why not you? Service is now Available throughout the United States and Canada! Write today for further information. SCHACHT MOTION PICTURE SCREEN CO, 2849 Sheffield Ave. Chicago, III. How Manj? Was this copy dog-eared when it came to you? How many men read it ahead of you? You would receive a clean, fresh copy if you had a personal subscription — and you wouldn't have to wait — you would be first to read it. Use the coupon below. INTERNATIONAL PROJECTIONIST 1 West 47th Street, New York, N. Y. Enter my subscription for n 1 year —12 issues— $2.00 n 2 years— 24 issues— $3.00 Name Address City State Local Local City and State Delegates 321 Tampa, Fla W. E. Sullivan 322 Charlotte, N. C Wm. H. Fowler 323 Springfield, 111 Chas. E. Horn 324 Albany, N. Y Andrew J. Antoinette 325 Wilkes Barre, Pa John B. Mitchell 326 Hot Springs, Ark Chas. S. Phillips 328 Pine Bluff, Ark Victor Vincent Vaught 329 Scranton, Pa John De Peep Lester De Vol 3.30 Fort Worth, Texas . . . Dan W. Gould 331 Temple, Tex Hallie A. Gee 332 Clinton, Iowa Claus Rief 333 Charleston, S. C Fred Randall 334 New Bedford, Mass. .Walter England 335 Bradford, Pa Robert W. Iver 336 Council Bluffs, Iowa. .Julius Lapidus 337 Utica, N. Y Glen Humphrey 338 Watertown, N. Y . . . . Henry Armstrong 339 Missoula, Mont Richard J. Hale 340 Nassau and Suffolk Counties, N. Y Louis Popiel 341 Oil City, Pa . W. A. McCIaren 342 Butler, Pa Paul E. Smith 343 Omaha, Nebr Howard A. Jackson .344 Olympia, Wash Boyd Andrews 345 Brockville, Canada. . C. J. Ford 346 Lexington, Ky E. B. Bush 347 Columbia, S. C Carroll L. Addy 348 Vancouver, Canada.. .Frederick G. Graham Locksley Clark 349 Lima, Ohio Harry Myers 350 Meriden, Conn Thomas J. Shea 351 Anacortes, Wash Thomas Watters 3.52 Springfield, Ohio R. W. Mills 3.53 Port Jervis, N. Y. . . . 3.54 Tulsa, Okla M. E. Hauptman 3.55 Sioux City, Iowa J. R. Marksbury 356 St. Paul, Minn Roy W. Moore 357 Kitchener, Canada . . . Harry Peer 3.58 Ogden, Utah Oliver Wheelwright 359 Trenton, N. J James Fee 360 Edmonton, Canada.. .William B. Allen 361 Kenosha, Wise Richard Schnell 362 Paterson, N. J Walter J. Penney Edward McGrath. Sr. 363 Reno, Nev 364 Akron, Ohio Harry Jones 365 Crawfordsville, Ind. . .Theodore Johnson 366 Westchester County, N. Y Nathan Storch Joseph Monaco 367 Evansville, Ind Otis Potter 368 Hutchinson, Kans Albert F. Weber 369 Huntington, W. Va.. .John A. Pfau 370 Richmond, Va H. L. Jarvis 371 Defiance, Ohio Howard R. Ward 372 Vincennes, Ind Frank Sparrow 373 Terre Haute, Ind .... Burton Steinhauser 374 Joliet, 111 Oscar Gardner 376 Syracuse, N. Y Harry Burgess 377 Ithaca, N. Y S. J. Klinko 378 Wichita Falls, Tex ... J. Max Ealy 379 Perth Amboy, N. J. . .Anthony Mazzeo 380 Oklahoma City, Okla. J. L. Bollman 381 Haverhill, Mass Fred Penwell .382 Holyoke, Mass David Taylor 383 Texarkana, Tex Clair Mozingo 384 Hudson;County, N. J . Edward J. Heyden Anthony Boscarelli 385 Burlington, Iowa Roy Standard 386 Columbus, Ohio Harry E. Coleman 387 Lawton, Okla Don Harvey .388 Youngstown, Ohio... .Jos. M. Steadman 389 Fort Dodge, Iowa. . . .John McCallum 390 Lynchburg, Va J. M. Burnett 391 Port Arthur, Tex Robert D. France 392 Kewanee, 111 Edward Lams .393 Mexic Corsicana, Tex.J. D. Walker 394 Appleton. Wis Julius Griem 395 Ann Arbor, Mich 396 Binghamton, N. Y. . .Henry Hudson Cole 397 Haverhill, Mass Jonathan A. Godfrej- 398 Meadville, Pa August Bodish 399 Bartlesville, Okla Floyd B. Blackman 400 Alexandria, La Ivy B. Jones 401 Centralia, Wash W. A. Kirkpatrick 402 Torrington, Conn. . . .William B. IngoIdsb\- 403 Sunbury, Pa Donald Treon 404 Topeka, Kans W. W. Reid 405 Knoxville, Tenn William M. Morton 406 Moose Jaw, Canada. .Walter Clarke 407 San Antonio, Tex. . . .William B. Keeler 408 Camden, N.J John McGinnis 409 San Mateo, Calif Warren H. Tillson 410 Manitowoc, Wis Elmer Erdraann 411 Williamsport, Pa Robert S. Mix 412 Bradentown, Fla James A. Scobie 413 Gadsden, Ala S. V. Bacon 414 Wicliita, Kans Frank E. Welsh 415 Tucson, Ariz Spiro E. Kontas 416 Rocliester, Minn Walter Ilesley 417 Durham, N. C Wm. D. Byrd 419 Decatur, III W. F. Arnold 420 Santa Ko,sa, Calif. . . .Wilfred J. LaCliapelle 421 Herrin, III Tony Malandrone 422 Ashtabula, Ohio E. Cecil Jones 423 Albuquerque, N. M.. .Lloyd Clark 424 Fall kiver, Mass Thomas Burke 425 Kankakee, III Oscar H. Sclimidt 426 Casper, Wyo E. R. Trollope 427 Rome, Ga M. B. Esserman 428 Stockton, Calif. . : . . . J. W. Soutliwick 429 Aberdeen, Wash Harry A. Thomas 430 Eureka, Calif Merv. K. Wagner 431 San Jose, Calif C. H. Tillson 432 Peterboro, Canada. . .Thomas J. Steiiton June 1932 INTERNATIONAL PROJECTIONIST 29 Local City and State Delegates 433 Davenport, Iowa Ross E. Huglies 434 Peoria, 111 John Wald 43.5 Salt Ste. Marie, Oan . . H. M. Ransonie 430 Winona, Minn Raymond Dexter 437 Brockton, Mass John L. Creed 435 Sherbrooke, Canada. .Arthus P. Dion 439 t»Jew London, Conn.. .Winslow \V. Lucas 440 St. John, N. B., Can... 441 Ottumwa, Iowa Francis Frederickson 442 Santa Barbara, Calif .. George Dalton 443 Jefferson City, Mo. . .Tom Menteer 444 New Kensington, Pa.. William Bordonaro 445 Bremerton, Wash. ... 1. .A. Chapman 446 .Astoria, Ore E. T. Edison 447 Springfield, Mo L. E. Glennon 448 Pueblo, Colo Robert G. Beecher 449 Stamford, Conn Nicholas Trimboli 4.50 Mason City, Iowa. . . .Frank E. Cawley 451 Sharon, Pa Norman Free borne 4.52 Pittsfield, Mass George H. Bissell 4.53 Willimantic, Conn John P. Moran 454 .Attleboro, Mass 4.55 Fort Smith, Ark H. Gratten 450 McKinney, Tex J. O. Belden, Jr. 457 Superior, Wise Erving G. Austin 4.58 Portland, Maine John A. Russell 459 Norwich, Conn Timothy J. Murphy 400 Racine, Wise S.J. Thomas 461 St. Catherines, Can.. .Fred Smee 462 Vineland, N. J John F. Rhodes 463 Pocatello. Idaho Joseph Arza Roskelley 464 El Dorado. Kans Harold Dull 465 Joplin, Mo Bert R. Carpenter 466 Fort Wayne, Ind Cliarles O. Smith 467 Fort William, Can Owen F. Beatty 46S Sherman, Tex Wm. R. Mereditli 469 Amarillo, Tex Solon May 470 Henryetta, Okla Barney H. Jameson 471 Okmulgee, Okla J. E. Shirley 472 Flint, Mich Paul Ricketts 473 Wilmington, Del Albert Williams 474 Rome, N. Y Lonnie Mason 475 Eau Claire, Wise Flovd E. Garton 476 Chicago, 111 Wm. Schraut 477 , Green Bay, Wise Richard O. Meister 4t8 Bethlehem. Pa . Charles Beyea 479 Norwalk, Conn Walter Blauvelt 480 Corning, N. Y 481 Lewiston, Mont Chester L. Palmer 482 Champaign Urbana, 111 J. E. Fruitt 483 Elgin, 111 Frank Stickling 484 Olean, N. Y 485 Union County, N. J. .George F. Gushing 486 Hartford, Conn Lazaro H. Stagg 487 Virginia, Minn Charles Essellstrom 488 Harrisburg, Pa Lawrence J. Katz 489 Gary, Ind George \'aicliis 490 Elkhart, Ind Fred R. Edwards 491 Parsons, Kans O. W. Mcintosh 492 Battle Creek, Mich. . .Harry M. Sloat 493 Janesville, Wise Carl E. Bunee 494 Frankfort, Ind Lester R. Jackson 495 Junction City, Kans. . 496 South Bend, Ind Lowell P. McGirr 497 McAlester, Okla 498 Kansas City, Kans. . .C. C. Bretz 499 Poughkeepsie, N. Y. .Edward M. Batey 500 Charleston, W. Va. . .J. G. Haley .501 Chico, Calif John H. Vaughan 502 Morris County, N. J.. Ira Troast 503 Mitchell,' S. D W. F. Voght 504 Santa Ana, Calif George B. Vest .505 Waltham, Mass P. J. Doheny 506 Anniston, Ala James T. Flanagan 507 Macon, Ga James O. Morgan .508 Oneida, N. Y 509 Duluth, Minn W. C. Kitzman 410 Fargo, N. D E. J. McCannell 511 Jacksonville, Fla John N. Spearing 512 Spartanburg, S. C. . . . Robert Shufford Beam 513 Tulsa, Okla Charles Hathaway 514 Bellefontaine, Ohio. . .Harry Chas. Johnston 515 Shamokin, Pa Jolin D. McAllister 516 Chester, Pa William Katz 517 Sapulpa, Okla William Rogers 518 Taft, Calif P. L. Owen 519 Mobile, Ala Henrv H. Link .520 Wilmington, N. C H. Clvde West .521 Long Beach, Calif W. E. Swank 522 Quincy, 111 Truman W. Vollmer .523 Quebec, Canada Jacques Berthiaume 524 Glens Falls, N. Y Ralph Guy 525 Aberdeen, S. D R. ^V. Merrifield .526 Orange, Tex AUie W. Barron 527 Marshalltown, Iowa. . Bruce Lowney 528 Kingston, Canada. . . .James Arthur Whitty .529 Long Branch, N. J . . .Lawrence J. Hines 530 Bristol, Tenn Lawrence D. Lowe .531 Petersburg, Va William E. Butler 532 Oswego, N. Y Alec Michalski 533 Frederick. Md Al. H. Stine .534 New Brunswick, N. J . Robert J. Richardson 5.35 Johnstown, N. Y William B. Miller 536 Red Bank, N.J Lester Burnette Davis 537 Talladega, Ala L. L. Cole .538 Westerly, R. I Gerald H. Payne 539 Anderson, Ind Chas. H. Hartley .540 Baton Rouge, La Oscar F. Rabenhorst .541 Elyria, Ohio .542 Marinette, Wise William H. Potter .543 Marietta, Ohio R. A. Skipton 544 Kokomo, Ind Fred C. Blacker 545 Miami, Fla James C. Noonan 540 Lowell. Mass Sidney LeBow 547 Florence, Ala J. M. Stutts 548 Greenville, Tex C. K. Peters, Jr. 549 Taunton, Mass George B. Bignell For More Light And Better Sound USED BY PARAMOUNT PUBLIX R. K. O. UNITED ARTISTS INTERNATIONAL VARIETY ETC. IT'OR every theatre there is one type and make of sound screen which will produce better results than any other. The length and breadth of the auditorium, the angle of reflection, the type of arc employed — all of these determine the kind of screen. But no matter what the shape and size of the theatre auditorium, there is one best sound screen to use — and ive have it • for you. Better pictures, greater attendance, and lower current costs follow the installa- tion of a VOCALITE or CHROMOLITE screen. SOUND SCREEN \i bcaliie Sound Saeen The Rrfef 1 Scm-n i-pvc and Ear w Roosevelt, New York _ SmmaScreen- Non-Glare -Diffusive Leadership is Progress NATIONAL Projector Carbons hold recognized leadership for all types of projection equip- ment. They keep pace with the progress of the Motion Picture Industry. They meet or anticipate each new demand. The new National S R A Carbons and Pre-Cratered High Intensity Carbons are recent improvements making possible better projection and steadier screen illumination. Use National Projector Carbons in yoiu" theatre. You will find the steady brilliance of screen illumi- nation pleasing to your audiences and a source of increased patronage. ON PROJECTOR CARBONS . . . Sold exclusively through distributors and dealers, I^ational Carbon Company will gladly cooperate with the producer, exhib- itor, machine manufacturer or projectionist on any problern involving light, NATIONAL CARBON COMPANY, INC. Carbon Sales Division • Cleveland, Ohio Unit of Union Carbide jim and Carbon Corporation Branch Sales Offices: New York, Pittsburgh, Chicago, San Franci 'co 550 Norfolk, \'a Frank M. Sutton 551 Shawnee, Okla C. R. Yowell 552 St. Petersburg. Fla. . .Jos. J. Johnson 553 Albany Decatur, Ala.. 554 Lebanon, Pa Ira J. Early 555 Atchison, Kans Coyte Wells 556 Sioux Falls, S. D Clayton W. Akin .557 Salem. Ohio James B. Engle 558 Daytona Beach, Fla. .Otto P. Forsyth .559 St. Joseph, Mo S. A. Wag>- 560 Richmond, Calif William E. Horton 561 Johnstown, Pa Ralph W. Briney 30 INTERNATIONAL PROJECTIONIST June 1932 International Photographer Is a finely printed and beautifully illus- trated monthly magazine owned by the West Coast Cameramen's Union In all matters concerning the profes- sional motion picture photographers of the country it is the official organ It is designed to appeal to amateur followers of 16mm. cameras as well as to the most advanced technicians The columns of the magazine recog- nize the close relationship between the photographer and sound recorder If your news or kodak dealer does not carry the magazine on its coun- ters write for a sample copy to INTERNATIONAL PHOTOGRAPHER GEORGE BLAISDELL, Editor 1605 North Cahuenga Avenue, Hollywood, Calif. 25 cents a copy $3 the year Local City and State Delegates 587 562 Hannibal, Mo 588 563 Danville, Va . Everett Haley 589 564 Modesto, Calif .Paul Aus brook 590 565 Centralia, 111 .Oscar Baker 591 566 McKeesport, Pa ... . .E. A. Barnes 592 567 Boone, Iowa .Erwin Kemble 593 568 Columbus, Ga . E. L. Gullatt .594 569 Douglas Bisbee, Ariz. .J. M. Claypool 595 570 Michigan City, Ind. . .8. C. Blande 596 571 Portsmouth, Ohio. . . . Berry L. Bellamy 597 573 Moberly, Mo . Don E. Mahoney 598 574 Greensboro, N. C . . . .Samuel P. Kersey 599 575 Pottstown, Pa .WiUiam J. MUler 600 576 Mansfield, Ohio .H. L. Straub 601 577 San Bernardino, Calif. Carl R. Douglas 602 578 Mbrgantown, W. Va . .C. P. DeFere 603 579 Woonsocket, R. I . . . .Alphonse Beaudoin 604 580 Windsor, Canada . . . . William D . Hawthorn 605 581 Batavia, N. Y . Harold M. Harris 606 582 Brantford, Canada. . .E. J. Harrington 607 583 St. Cloud, Minn. . . . 608 584 Abilene Breckenridge 609 Tex .H.:D. Hill 610 585 Allentown, Pa .LeRoy F. E. Rau 611 586 Columbus, Nebr. . . . .Floyd L. Kerwood 612 Marshall, Tex Elmer C. Ward Muskegon, Mich L. B. Wallace Jackson, Miss Joe A. Kuriger Greenwood, Miss George R. Lehr Hagerstown, Md John Slack Saratoga Spgs., N. Y.William J. Carroll Creston, Iowa Chas. F Craig Nanty Gl, Pa Maurice Fruhlinger Carthage, Mo Rex. B. Mealey Greenfield, Mass Leslie Pervere Waco, Tex Carl R. Lemke Marion, Ohio Fresno, Calif W. H. Lingle La Salle, 111 Vincent F. Daniels Benton Harbor, Mich. Kenneth F. Brown Trinidad, Colo Robert Micek Raleigh, N. C Arthur Pakula Corpus Christi, Tex. .C. L. Nelson Visalia, Calif Arthur I. LeCavalier Wausau, Wise Woodward Bierbrauer Kittanning, Pa Blair T. Anderson Boulder, Colo Ernest Grain Caywood Little Falls, N. Y . . . . Benjamin O'Donnell Fort Madison, Iowa. .L. F. Schulte Watsonville, Calif. . . .James W. Wilson Franklin, Pa Myrl D. Wilson 613 Salem, Ore . Rodney Martin 614 San Bernardino, Calif.Jasper E. Cline 615 Hattiesburg, Miss. . . .H. W. DeWitt 616 Meridian, Miss .Frank Forten berry 617 Greenville, Miss .Wilbur G. Dawson 618 Bloomington, Ind . . . .Ed. Parham 619 Alexandria, Va . 620 Pontiac, Mich . Earl Ross 621 Erie, Pa .L. D. Smith 622 Port Huron, Mich. . . .Lowell G. Keeslar 623 West Palm Beach, Fla.John W. Cummings 624 Lewiston, Me . Carleton C. Coffin 625 Tyler, Tex .W. W. Renfro 626 Nashville, Tenn . Robert E. Fowlkes 627 Washington, Pa .Everett W. Seal 628 Charleroi Monessen, Pa .James A. Woods, Jr. 629 Idaho Falls, Idaho.. .L. F. Collins 630 Peru, Ind . Claude McElheny 631 Orlando, Fla . Bryan McGee 632 Fort Scott, Kans .Ted R. Jeffries 633 Cambridge, Ohio . C. E. Lyne 634 Sudbury, Canada. . . .Harry L. Walker 635 Winston Salem, N. C.Paul Peddicord 636 Lewistown, Pa , 637 Kingston, N. Y . Frank A. Hopper 638 Carbon County, Pa. .Andrew F. Hammel 639 Jackson, Tenn .Paul Burke 640 Nassau and Suffolk Counties, N. Y. . . .Joseph W. Engle 641 Arkansas City, Kans .ChariieH. Gresty 642 Bergen County, N. J .Lester Clutterbuck 643 Lakeland, Fla .Lee Gregg 644 New York, N.Y.... .F.Walter Strange O. V. Johnson 645 Rockland rCounty, N. Y .Joseph A. McGlynn 646 Fort Lauderdale, Fla ..A. L. Cash 647 Cheyenne, Wyo . Roy Crawford MH Provo, Utah • Earl Graham 649 North Platte, Nebr.. .8. Schmalzried 650 Westchester County, N. Y . James J. Shaughnessy Arthur Martens 651 Wenatchee, Wash. . . .William Harrison Hauber 652 Dodge City, Kans... .La Verne Davis 653 Lorain, Ohio .Thomas M. Smith 654 Minot, N. D • John S. Ceglowski 655 Sheboygan, Wise .Thomas Kernen 656 ElCentro, Calif . George Abrams 657 Leavenworth, Kans. .Ernest J. Lord 658 Jacksonville, 111 , 659 Los Angeles, Calif. . . . Jackson Rose Frank B. Good Paul Perry Roy H. Klaffki J. P. Whalen Irving Auerbach Raleigh B. Nicholas Alvin Wyckoff Howard E. Hurd 660 Huntington, Ind . . . .Malcolm Yarger 661 Reading, Pa .LeRoy Talbot 662 Danbury, Conn . Irving C. Lown 663 Lewiston, Idaho .Hobart D. Burns 664 Prince Albert, Can . . Robert Evan Price 665 Toronto, Canada 666 Chicago. Ill . Eugene J. Cour William H. Strafford Charles N. David 667 Lethbridge, Canada . . Percy N. Morris 668 Monroe, La .Wm. Walter Veach 669 New York, N. Y. . . . . Saul E. Harrison John Hans 670 Goldsboro Wilson, N. C . Robert B. Best j 671 Canton, Ohio . Ray A. Bederman J 672 Klamath Falls Med ] ford. Ore .John Widner 1 673 Lubbock, Tex .Kenneth R. Brock 1 674 Biloxi Gulfport, Miss .William E. Sexton i 675 Eugene, Ore .Louis Gibbs 676 HorneU, N. Y 677 West Warwick, R. I. .Lester P. Slater 678 Laredo, Tex . J. L. McElyea ; 679 Miami, Okla . Ray A. Riddle 1 680 Halifax, Canada . . . .Arthur M. Crowell 681 Gillespie, 111 .John Peart 682 Lancaster, Pa .Cecil Patterson 683 Los Angeles, Calif. . . . Carl J. Kountz Gervase Maguire Thos. C. Bryan Theo. Sullivan Thomas Malloy Hugh H. Gwynne 684 Mankato, Minn .Anthony J. Koll 685 Concord, N. H .Bradley Callahan 686 Sussex County, N. J. 687 Beatrice, Nebr .John I. KeUy 688 Harlingen, Tex . Ray Wilson 689 Grand Jet., Colo . Chas. P. Webber 690 Iowa City, Iowa .... . George Harry Bleeker 691 Salem, Mo .George R. Hart 692 Latrobe, Pa .John E. Packerene 693 Brownwood, Tex. . . . .Howard E. Reed 694 Beaver Dam, Wise. . .Lee J. Favour 695 Hollywood, Calif. . . . .Dean C. Daily Karl E. Zint Al. Blodgett Harold V. Smith Neil P. Jack 696 Newcastle, Ind .Geo. R. Mattox 697 Greenville, S. C . Hembry L. Machen 698 Bismarck, N. D .H. J. Franek 699 Johnson City, Tenn . .H. B. Crowe II TWO NOTEWORTHY ACHIEVEMENTS IN PROJECTION EQUIPMENT Complete rear shut- ter attachments show- ing framing device, shutter adjusting de- vice, framing light, hinged eye shield, cooling plate, fire shutter lever and gate opening device. New Low Price: $85 B. & S. Rear Shutter reduces aperture heat by 70%, minimizes effect of warped and buckled film, and keeps film free from dust and dirt. Exclusive blade feature of this shutter keeps hot air from film and insures constant supply of cool air around the aperture. The results of a test by the Massachusetts Department of Public Safety in a Boston theatre on Janu- ary 19, 1930, are as follows: Without B. & S. Rear Shutter Aperture Heat: 1250° F. With B. & S. Rear Shutter Aperture Heat: 340° to 350° F. Installation can be made in one hour on any single- or double-bearing projector mechan- ism, without any cutting or drilling. Periodic oiling is the only maintenance requirement. Rear shutter equipment includes cooling plate, framing device, shutter timing adjust- ment, and a framing light. A hinged eye shield permits easy accessibility to the me- chanism. ♦ B. & S. Change-over consists of two shutter blades contained in a housing de- signed for attachment to the cone of the lamphouse and operates on either A.G. or D.G., at 110 to 125 volts. Novel design eliminates any possibility of double exposure on the screen, and makes the change invisible to the audience. B. & S. Change-overs operate efficiently on either A.C. or D.C., but coils for the proper current will be supplied on specification. Coils of the B. & S. Change-over will stand up under heavy overloads and will not burn out. The constant arcing in an ordinary change-over switch soon causes the metal contacts to burn and corrode. All B. & S. switch contacts are made of carbon that cannot corrode. B. & S. unique design also prevents the flash from touching any part of the sw^itch. This switch cannot stick or bind and is positive in operation. B. & S. Change- overs have been used for many years in Publix, R-K-O, and other major theatre circuits. Write for particulars to BASSON & STERN For fifteen years manufacturers of high grade motion picture equipment 749 EAST 32nd STREET, BROOKLYN, N. Y. Ove 400 THEATRES USE Quality guaran- teed by seven years experience in the manutac- t u r e of Photo- electric Ceils. There's a Visitron for every make and model of sound-film equipment, including yours. Write us for details. Don't be misled by any "just as good" statements. Insist on Visitrons — look for the name on the metal plate. PHOTOELECTRIC CELLS Day by day, the number of yisitron users and boosters increases steadily. Extraordinary bril- liance and lasting quality of tone reproduction; absence of trouble and nninimum need for ad- justments and replacements have firmly estab- lished Visitrons as the outstanding photoelectric cell value. They cost no more in the beginning than other high quality cells, and decidedly less in the long-run. . . . "Install Visitrons and forget your cell worries", is the outspoken advice of one leading projectionist. Four thousand others agree with him. But, you don't have to take anyone's word for it — Try a Visitron, yourself — Today! ^ Manufactured by G-M LABORATORIES TnC. 1737 Belmont Avenue Chicago, Illinois Order VISITRONS by name from [ NATIONAL THEATRE SUPPLY COMPANY PROJECTIONIST £d/tecfby James J. Finn "Peak Grid Swixg'' and a GOOD SHOW Engineers in their labs and projectionists in their theatres deter- mine good tubes by different methods — and both put a big, hearty O. K. on DUOVACS. The engineer will chase electrons around the block and destroy their private lives. He wants good performance down on graph paper. The projectionist doesn't want to look sideways at his tubes every time he cuts nhem in. He wants good performance on the screen for the cash customers. A large and constantly growing group of projectionists who have to double as engineers are following in the footsteps of the big De Luxe chains and standardizing on DUOVACS — lower first cost; longer life; superlative, trouble free operation. ALL TUBES FOR EVERY MAKE OF FILM AND DISC APPARATUS A complete line of Duovac Tubes is available for every standard and special make of sound projection equipment. The Duovac staff of engineers is always ready to advise you without obligation on your requirements, no matter how small they may be at the moment. DUOVACS for EVERY SOCKET on EVERY SOUND CIRCUIT DUOVAC RADIO TTBE CORP. 360 FURMAN STREET BROOKLYN, NEW YORK > ol. 3. No. 1 Jiilv. 1932 ■BBMI A magazine devoted to heller visual and sound re^r^^wtiot^ 25c. a c< $2.00 a y TWO NOTEWORTHY ACHIEVEMENTS IN PROJECTION EQUIPMENT Complete rear sluii- ter attachments show- ing framing device MWm shutter adjusting de- vice, framing light, i -^ WBSItml^S^^^M hinged eye shield, cooling plate, fire shutter lever and gate opening device. M^^W^^SH H i(W HImMI^HI Mm Mm • % ^^n ^^u^ >-HI Hi: ' ^^H If ' rau^^^H t^ W^i P^vl^^^^HI E^ iS^^^^^HH ^S^^^^^^E imI^HK '1 '4 Hi •% I'V ^ji^Bf ■II .^^Ht •m^M ■■ppppup ^ I New Low Price: $85 B. & S. Rear Shutter reduces aperture heat by 70%, minimizes effect of warped and buckled film, and keeps film free from dust and dirt. Exclusive blade feature of this shutter keeps hot air from film and insures constant supply of cool air around the aperture. The results of a test by the Massachusetts Department of Public Safety in a Boston theatre on Janu- ary 19, 1930, are as follows: Without B. & S. Rear Shutter Aperture Heat: 1250° F. With B. & S. Rear Shutter Aperture Heat: 340° to 350° F. Installation can be made in one hour on any single- or double-bearing projector mechan- ism, without any cutting or drilling. Periodic oiling is the only maintenance requirement. Rear shutter equipment includes cooling plate, framing device, shutter timing adjust- ment, and a framing light. A hinged eye shield permits easy accessibility to the me- chanism. B. & S. Change-over consists of two shutter blades contained in a housing de- signed for attachment to the cone of the lamphouse and operates on either A.G. or D.G., at 110 to 125 volts. Novel design eliminates any possibility of double exposure on the screen, and makes the change invisible to the audience. B. & S. Change-overs operate efficiently on either A.G. or D.G., but coils for the proper current will be supplied on specification. Coils of the B. & S. Change-over will stand up under heavy overloads and will not burn out. The constant arcing in an ordinary change-over swtch soon causes the metal contacts to burn and corrode. All B. & S. switch contacts are made of carbon that cannot corrode. B. & S. unique design also prevents the flash from touching any part of the switch. This switch cannot stick or bind and is positive in operation. B. & S. Change- overs have been used for many years in Publix, R-K-O, and other major theatre circuits. Write for particulars to BASSON & STERN For fifteen years manufacturers of high grade motion picture equipment 749 EAST 32nd STREET, BROOKLYN, N. Y. July 1932 INTERNATIONAL PROJECTIONIST Defective Equipment Is A Serious Handicap To The Projectionist And Consti- tutes A Grave Fire Hazard Upon Request We Will Be Pleased To Send New Booklet Giving Full Particulars Regarding The New SOUND PROJECTOR INTERNATIONAL PROJECTOR CORPORATION 90 SOLD STREET NEW YORK, N. Y. INTERNATIONAL PROJECTIONIST July 1932 A NEW BOOK BY CAMERON QUESTIOIVS & ANSWERS (SOUND MOTION PICTURES) THE SUBJECT OF RECORDING AND REPRODUCING OF SOUND MOTION PICTURES COVERED IN QUESTION AND ANSWER FORM Here are 35 of the 542 questions that Canadian projectionists must be able to answer correctly to obtain a "grade A" card. HOW MANY OF THESE CAN YOU ANSWER CORRECTLY? If excessive plate current develops, what would you do? How is amplification accomplished? Would any kind of synchronized motor or constant speed motor do for sound projection? Why are all the wires carrying sound or speech, lead covered and again en- closed in conduit? What is the "gain" control, and what are its functions? What would a low plate reading on the panel indicate? How many tubes in a D. C. and A. C. motor control cabinet? The photo-electric cell has a silvered lining, and one wire is connected to the lining. Is this wire positive or negative? Does the voltage to the photo-electric cell cause a steady current flow? What and where is the grid leak in the amplifier? What is the function of the exciting lamp? What is the action of (a) the plate (b) the grid (c) the filament in a va- cuum tube? What might result from placing motor generator sets and batteries in the same room? Explain what a rectifying tube does? What is "specific gravity"? What are the causes of motor-boating? Why does the needle on the disc travel from the centre of the disc to the out- side? On Vitaphone disc, is the sound rec- orded on the bottom of the track or groove, or is it cut into the walls of the groove? What apparatus do the "H" batteries supply with current on W. E. and N. E. equipment? Should all motor generator sets be grounded? If so, state why. What is a prismatic condenser? When using a prismatic condenser, will the condenser be closer to the aperture than if you used a piano condenser? Can a prismatic condenser be used when showing slides? When using a Cinephor condenser sys- tem, is accuracy in the focal distance of much importance, and why? Can a cracked mirror or condenser be used with mazda projection? What will be the result on the screen? What is the average amperage on (a) high intensity (b) reflector arc (c) hi- low arc? If the voltage drops, what effect will the cutting out of resistance have? In an electric arc circuit, what various things offer resistance to the flow of current? What is the standard aperture size? Why does a cracked condenser show up when projecting slides and not when projecting film? Define the following: collector lens, piano lens, meniscus lens, converging lens, condensing lens. What is absorption of light? What is the optical axis? What causes film to buckle, and what effect has this on the screen? Which make of projector has an actual faster movement — that is, the movemeni of the intermittent from full rest to full rest? All of the 542 Canadian examination questions, with several hundred others, are answered for you in this new book. The subject of Sound Motion Pictures fully explained in an "easy-as-A. B. C." manner. 240 PAGES— OVER 1,000 EXAMINATION QUESTIONS WITH ANSWERS— PRICE $3.50 CAMERON PUBLISHING CO. Woodmont, Conn. Here is my Three dollars fifty cents, send me my copy of QUESTIONS AND ANSWERS ON SOUND MOTION PICTURES. Name Address I. p. July 1932 INTERNATIONAL PROJECTIONIST POECTION Edited by James /. Finn Volume 3 JULY 19 3 2 Number 1 Monthly Chat 5 Vibration: Relentless Enemy of Good Projection 16 Lubrication of Motion Picture R. G. Hess Film J. L Crabtree C. E. Ives 7 Electrical Reflections Data Com- piled at Bell Laboratories Exciter Lamp Life and Perform- 17 Special Projection Council Meet- ing in New York 10 ance Harold W. Watkins R. E. Farnham 18 Superior Craftsmanship is Best Jean A. Le Roy 20 Fire Insurance M. D. O'Brien 11 The Editorial Page Diseases of the Upper Respira- 21 "It Can't Happen to Me" 12 tory Tract Harry W. Brown, M.D. 23 Notes on the Auditory Response Change to New Aperture Shows of the Human Ear 13 Economies 23 The Question of Service for Sound Systems 14 Policies and Practices Occupational Hazards of the Pro- 24 James J. Finn j^ectionist Miscellaneous Items 25 Progress in the Motion Picture News Notes Industry 15 Technical Hints Published Monthly by JAMES J. FINN PUBLISHING CORP. 1 WEST 47th STREET, NEW YORK, N. Y. West Coast Representative Hallett E. Cole, 218 Haas Building, Los Angeles, Calif. (Thone: Tucker 6428) Subscription Representatives Australia and New Zealand: McGills, 183 Elizabeth St., Melbourne England and Dominions: Wm. Dawson & Sons, Ltd., Pilgrim St., London, E. C. 4. Yearly Subscription : United States and possessions, $2 (two years, $3) ; foreign countries, $2.50. Single copies, 25 cents. Changes of address should be submitted two weeks in advance of date of publication to insure receipt of current issue. Entered as gepojidpUs? matter February 8, 1932, at the Post Office at New York, N. Y. under the act of March 3, 1879. Entire contents coiSyrighted 1932 by James J. Finn Publishing Corp. International Projectionist is not responsible for personal opinions appearing in signed articlr* in its columns. MONTHLY CHAT WITHIN the confines of this issue appear many items which may best be described as "seasonal." The alert business agent will con the pages with shears in hand and should be able to glean therefrom a substantial addition to his larder. Catch on? ... or must we go into detail? THAD BARROWS, of Boston L.U. 182 and prexy of the P.A.C., may be blamed for this story about Stanislaus Hausner, member of L.U. 306, who re- cently was forced down in mid-ocean while attempting a projected flight from New York to Warsaw. It seems that Hausner, according to Barrows, was so interested in a copy of International Projectionist that he really didn't no- tice several ships that passed his floating plane. The fact is that the foregoing is an even better story than Barrows figured it to be: for when Hausner arrived back home in New York, he admitted that it was true. IN playing fair with our readers, we'll give our competitors (such as they are), a break. What everyone seems to want to know, but is having a devil of a time finding out, is just what equipment and how much adjustment and what is the total cost of adapting existing sound reproducing apparatus to the much-pub- licized but closely guarded "extended fre- quency range" system. If anyone should uncover any facts relating to this mystery, would they please be kind enough to notify either Western Electric Co. or RCA- Victor, Inc., or both. These companies likely will welcome such information themselves. OUR comment in the last issue anent rear projection stirred up a lot of interest in the projection field. Well, this month we unload ourselves of an- other burdensome question: Should film be waxed, and if so, how? Also, and between the same covers, we have our fling at the matter of servicing sound equipments. If we live out this month without suffering bodily harm, we shall feel reasonably sure that the so-called "freedom of the press" exists in fact as well as in fancy. ONE upstart projection supervisor has unburdened himself of the idea that "too much supervision, particularly by district men, is undesirable." We agree — particularly when the field men know more about projection than does the national supervisflr* INTERNATIONAL PROJECTIONIST July 1932 Strong Electric Change-overs FOR REAR SHUTTER MOUNTING The "Super" For mounting on a rear-shutter Simplex or at the port opening for use with any projector Specifications: Cast aluminum housing. Black crakle finish. Aluminum blades. Asbestos cover- ing. 110- volt coils (specify whether A. C. or D. C. wanted). Patented automatic current cut-off which cuts the current off the coils auto- matically. You Can't Burn Out the Coils Furnished with 5-foot lead wires and conduit. A space is provided to install op- tical glass when mounted at the port opening. $40 each FOR FRONT WALL MOUNTING The "Special" A new member of the famous Strong family of high-grade elec- trical projection equipment Exactly the same in every way as The "Super" except that it does not in- clude the automatic current cut-off feature. The greatest value in an electric change-over available today. All orders should specify whether for rear shutter or port hole mounting and whether A. C. or D. C. coils are desired. $30 each The name **Strong'* on a change-over has stood for precision projection work for more than 15 years. There is no substi- tute for a Strong Change-over. Sold and Serviced by All Leading Dealers. Manufactured by ESSANNAY ELECTRIC MFG. CO. 1049 No. Hermitage Ave. Chicago, nimois I INTERNATIONAL PROJECTIONIST VOLUME III NUMBER 1 JULY, 1932 LUBRICATION OF MOTION PICTURE FILM J. /. Crahtree and C, E. Ives*^ WHEN freshly developed or so- called "green" motion picture film is passed through a pro- jector, there is a tendency for an in- crustation to accumulate on the aperture plate and tension springs, which retards the free passage of the film through the machine. Chemical analysis has shown that this incrustation consists largely of gelatin with more or less silver, dirt, carbon dust, and oil, but it contains usually only a trace of the metal or alloy of which the gate is composed. The effect of the incrustation is two- fold, namely: (a) It increases the fric- tion between the metal parts of the gate and the gelatin coated surface of the film. This causes excessive strains on the edges of the perforations at the pull- down sprocket which ultimately results in torn perforations and, therefore, a diminishing projection life of the film, and (6) The film is no longer held flat in the gate but oscillates in and out of the focal plane, producing the well known "in-and-out-of-focus" effects. Also, since the film is in a condition of varying strain between the intermittent sprocket and the aperture, the projected picture is unsteady. A similar action at the sound aperture causes a flutter in the * Kodak Research Laboratories, Rochester, N. Y. volume and frequency of the reproduced sound. If developed motion picture film is examined under a microscope by re- flected light, it is seen that the gelatin surface is covered with innumerable ex- trusions (see Fig. 1, magnification 540), which impart a definite degree of rough- ness to the film. It is possible to smooth the film surface either by grinding away or burnishing down the minute projec- tions or by filling-up the crater-like de- pressions. The effect of filling-up the depressions with wax and then polishing is shown in Figure 2, the left-hand side of which shows the surface of untreated film (magnification 540), while the right-hand side shows the same film after applying wax and burnishing. The Burnishing Effect Tests have shown that the mere act of burnishing or polishing the film surface without the application of a lubricant, such as wax or oil, does not appreciably facilitate the passage of the film through the projector gate. It is well known, however, that film which has been pro- jected once or twice has a much less tendency to produce an incrustation on the gate than "green" film, and this is usually attributed to the burnishing or polishing action of the aperture plate or [7] pressure springs on the gelatin coating of the film. The burnishing effect produced by projecting film in a Simplex projector ten times is very slight as shown in Figure 3 (magnification 540). This is a photomicrograph of the film surface in the region between the perforations. The lower half of the figure shows a portion of the film surface which was in contact with the aperture plate, and it is apparent that the burnishing effect on the film surface was almost negligible. Effect of Oil It is considered that traces of oil which are transferred to the film surface during the first projection are chiefly re- sponsible for the increased ease of pas- sage of the film on subsequent projec- tion. It is obvious also that the moisture content and degree of hardening of the gelatin coating are important factors which determine the rate of form.ation of the incrustation on the gate. If the gelatin coating of the film contains an excess of moisture, it tends to soften and become "tacky" much more readily in the hot projector gate than is the case with dry film. This tendency of the gelatin coating to soften under the action of heat can be diminished by hardening 8 INTERNATIONAL PROJECTIONIST July 1932 during processing; but excessive harden- ing tends to increase the brittleness of the film and is not to be recommended. The following factors also determine the extent of the formation of the gate incrustation : (a) The Tension of the Gate Springs. This should be of the order of 8 ounces for each spring or a total of 16 ounces. The spring tensions should be adjusted individually at intervals by attaching a spring balance to the upper end of a narrow film strip placed at one side of the gate and increasing or decreasing the gate tension until the film just com- mences to travel upwards, when the spring registers 8 ounces with an up- ward pull. In a like manner, the ten- sion with full-width film should be ad- justed to 16 ounces. (b) The Nature and Smoothness of the Gate Surfaces. The nature of the gate material in contact with the film surface, providing it is of sufficient hard- ness, is of less importance than its de- gree of smoothness. Satisfactory ma- terials are cast iron or stainless steel, either plain or chromium plated. Corro- sion should be carefully guarded against and any gelatin incrustation removed with a soft metal scraper, such as a coin, so as not to scratch the polished surface. (c) The Temperature Existing at the Gate. As explained previously, the tendency of the gelatin to incrust on the gate springs, in the case of freshly proc- essed film, increases with the tempera- ture. Any means of reducing the gate temperature, such as by the use of heat- absorbing glass, a water cell, radiating fins on the gate, or a blast of air im- pinging on the gate, produced either by a separate blower or by fan blades on the rear shutter, are desirable. Methods of Facilitating the Passage of Film Through the Projector Even though a projector is in good mechanical condition and the foregoing requirements are fulfilled, there is in- variably a tendency for a gate incrusta- tion to form with "green" film. Numer- ous methods of treating film to offset this have been suggested from time to time, as follows: 1. By coating the entire surface of the film with a suitable lubricant. Ex- tensive tests have shown that of the various available lubricants, paraffin wax or machine lubricating oil are the most satisfactory lubricants for motion picture film. Only the merest trace of wax or oil, however, is necessary. This can be demonstrated readily by the following experiment : Place a piece of motion picture film, gelatin side upwards, on a flat table anc' scrape the surface with the edge of f Do Your Share I W/^ AXING of motion picture film long has been a contentious ▼▼ topic among projectionists, laboratory workers, exchange men arid theatre owners and managers. It is generally recog- mzed that fihn must be lubricated to assure unimpeded transit on Its first runs through the projector. Opinion is sharply di- vided, however, as to how best to accomplish this lubrication. Various methods of lubricating film are described in the ac companying article by Messrs. Crabtree and Ives. One of these methods, that of edge lubrication, is preferred— akhough the writers specifically cite the strict necessity for employment of the correct concentration of wax and proper equipment. Bearing oh this highly important question is the appended abstract of a discussion incident to the reading of the Projection Practice Committee report at the last meeting of the S.M.P.E. Comment by Messrs. Crabtree and Edwards is self-explanatory and reflects accurately the prevailing difference of opinion on this topic among research workers and projectionists — with the former being in the position of rolling the bullets, so to speak, and the latter having to fire them. It is of the utmost importance that a solution to this pressing problem be found. Calculable damage — film mutilation, damage to projector parts, and, frequently, fire loss— runs into many thousands of dollars annually. The loss occasioned by inferior projection — scratches, etc. — cannot, of course, be reduced to terms of dollars and cents. The question is: What is wrong with the present method of waxing film? This query involves considera- tion of (1) the method itself; (2) the application of the method in laboratories, and (3) the results obtained in theatres. The last-named is by far the most important consideration. Any waxing process that does not give good results in the projec- tion room is worse than useless: it is a positive menace to safety and a bar to good projection. The projectionist is best in a position to pass judgment on the merits or demerits of the waxing system as at present constituted. His is the experience that counts, that provides the answers to such questions as: To what extent is wax accumulating in the gates of projectors today? Does the accumulation consist of wax, dirt, gelatin, or a mixture of these? What is wrong with the present methods? The projectionist is strategically situated to render a great service to projection, to his craft and to the industry generally by contributing his findings to this symposium on present waxing conditions which will be conducted by International Projec- tionist with the cooperation of Eastman Kodak Company. Every projectionist who can possibly do so should contribute to this symposium. Opinions based on daily experience in the projec- tion room are desired. A majority of the opinions will be pub- lished in these pages. A sufficient number of contributions, if indicative of the need for a change, would pave the way toward the application of corrective measures. Address all communications to International Projectionist. coin. It will be noticed that the surface is very readily scratched. Now. pass the finger through the hair, rub across the surface of the film, and again scrape the surface of the film with the coin. It will now be noticed that the coin passes smoothly and easily over the film surface without producing scratches — as a result of the transferance of a small quantity of oil from the hair to the film surface. Surface treatment of the film with a suitable wax has several advantages as follows : (a) The film has much less tendency to become scratched; (b) The natural moisture in the gelatin tends to be retained, thus preserving the flexibility of the film; (c) If oil is splashed on the film, the oil spots are not visible on the screen, whereas with un- July 1932 INTERNATIONAL PROJECTIONIST FIGURE 1 FIGURE 2 FIGURE 3 Fig. 1 : Photomicrograph showing appearance of surface of motion picture film by reflected light. Fig. 2 : Photomicrograph showing (A) untreated film, and (B) effect of coating film surface with wax and then polishing. Fig. 3: Showing burnishing effect on film during projection. Upper half — unbumished; lower half — burnished treated film the oil spots are very objectionable on projec- tion; and (d) Extensive tests have shown that the film has a much less tendency to accumulate ground noise with use. If a soft wax coating such as paraffin is used for the surface treat- ment, it is apt to attract dirt; so it is preferable to use very hard waxes which, in turn, are not the best lubricants. The necessary lubrication is provided by applying a lubricating wax or oil to the edges as described hereafter. The above double treatment of film is relatively expensive, and due to the ad- vent of biased recording and the greater care with which film is handled, ground noise is not as serious a factor as was previously the case. Lubricating Film Edge 2. By treating the edges of the film with a suitable lubricant such as paraffin wax or lubricating oil. A number of years ago it was custom- ary to apply a thin line of wax along each edge of the film surface and be- tween the perforations by means of a S.M.P.E. Symposium on Waxing Mr. Crabtree: I noticed that the committee regards the waxing of film as undesirable. With the early method of \fraxing, when the film in the waxing machine became too cold, it accumulated on the blades and was ap- plied too thickly to the film. It then caused trouble at the projector gate. But I should like to recommend a change that has been made — to use a solu- tion of the wax, the concentration of which controls the amount of wax ap- plied, so that it is impossible to apply too much wax unless the solution is too concentrated. I made a survey of the different laboratories in New York, and found that 95 per cent of them are using a solution of wax for edge wax- ing. To what extent is wax accumulating in the gates of projectors today? Does the accumulation consist of wax, dirt, gelatin, or a mixture of these? What is wrong with the present method? Mr. Finn: It doesn't require extended research to uncover the fact that waxing of film is, to say the least, undesirable. I don't think it pre- sumptuous to state that a majority by far of projectionists do not desire that film be waxed — that is, as waxing is now done by certain laboratories. Mr. Richardson: The chairman of the Committee is a supervisor of projection, and everyone on the Committee engaged in practical projection made the statement that no method of waxing has yet been used that would not result in some deposit in the sound gate. Yesterday we were told that waxing of film to be used in the Navy's projectors is taboo. It was said that there is no waxing process that is not objectionable. Mr. Edwards: I agree with Mr. Richardson. Our experience in a first- run film house has shown that it is necessary to take out the sound gate and clean out the accumulation of wax after every running. If this is not done, we soon find that we have a "frozen" film in the gate. Mr. Crabtree: Yet 95 per cent of the laboratories are using this pro- cess of waxing. I feel that if trouble is being experienced, the laboratories are using a stronger solution of the wax than is recommended. Mr. Edwards: It is quite possible that the fault lies not so much in the process as in the application of the process. Probably as much care is not taken in applying the wax as was intended by the inventors of the system. We have to dig out the wax from the grooves in the rollers up to the tenth run. If neglected for one reel, we often find that the heat of the plate will melt the wax and the film will adhere to the gate. machine similar to that illustrated in Figure 4. This machine consists essen- tially of two parallel thin steel disks separated by a distance of 1 3/32" ro- tating in a vertical plane. The disks dip into a bath of molten paraffin wax and apply the wax to the film at their upper edge. The quantity of wax applied is controlled by the thickness of the disks, the temperature of the molten wax, and the rate of travel of the film. The above method of lubrication is entirely satisfactory, providing the wax is applied correctly. However, if the temperature of the molten wax is not sufficiently high during application, too much wax is applied by the disks and this does not solidify sufficiently before the film is rewound. This causes the wax to cement the edges of the film convolutions, so that on rewinding, particles of wax are torn away from the film and these tend to incrust on the picture area, causing spots and splotches on the film. Particles of wax also tend to lodge on the sound track with deleterious effects and they likewise accumulate in the re- producer aperture, thereby diminishing the volume of reproduced sound and, in some cases, cutting off the sound com- pletely. Another very serious danger resulting from the application of an excess of wax arises if the projector is threaded while hot with film coated with an excessive quantity of wax. As the projector cools, the wax solidifies and holds the film so tightly that on starting the projector, the intermittent sprocket may tear out the perforations instead of pulling the film down through the gate. Also, since the fire shutter opens immediately when the projector starts, more or less film is apt to be burned up if the film does not start to move down promptly past the aperture. Repeated tests have shown, however, that this trouble is not likely to occur 10 INTERNATIONAL PROJECTIONIST July 1932 unless the film contains five or six times the quantity of wax normally applied by the waxing machine. 3. A much more satisfactory method of edge lubrication consists of applying a solution of wax or oil in a solvent by means of the machine shown in Figure 4. The advantages of using a solution of wax in a solvent such as carbon tetra- chloride are briefly as follows: (a) No heating unit is necessary and thereby the fire hazard is removed. {b) Extremely small quantities of wax may be applied con- sistently. (c) The quantity of wax applied is independent of the temperature and is determined only by the concentration of the solution, the width of the blades, the speed of rotation of the blades, and the rate of travel of the film. If the correct concentration of wax is used, — namely, 5 per cent or 6y2 ounces of wax in 1 gallon of carbon tetrachlor- ide— this means that only 4 grains of wax are applied to each 1,000 feet of film, and with this quantity no visible accumulation of wax should occur in the projector gate even after projecting six or seven rolls of film. During a discussion on theater prac- tices at the recent convention of the Society of Motion Picture Engineers at Washington, D. C. Mr. G. C. Edwards', a supervisor of projection, stated that he had recently encountered difficulty due to the accumulation of an excessive quantity of wax in the projector gate. An investigation revealed that the labo- ratory which processed the film in ques- tion was using the solution edge waxing method, so that it could only be con- cluded that the laboratory was either using a solution of wax which was too 1 Brooklyn, (N. Y.) Strand. Past President, American Projection Society. FIGURE 4 Showing application disks of new East- man ' edge waxing machine which apply a 5 per cent solution of paraffin wax in carbon tetrachloride to the edges of the film. On evaporation of the solvent, only the merest trace of wax remains on the film; but experi- ments have shown that only 4 grains of wax per 1,000 feet of film are necessary to provide adequate lubrication concentrated, or the solution in the application pot had been allowed to concentrate by evaporation of the solvent in contact with the air. Practical tests have shown that a solu- tion having a concentration as low as 2 per cent of paraffin wax in carbon tetrachloride, in most cases, will give satisfactory lubrication. 4. Other miscellaneous methods of lubrication which have been proposed from time to time consist of the follow- ing: (a) The application of a lacquer over the entire gelatin surface of motion picture film. Such lacquer coatings are non-lubricating although they have the advantage that if oil has access to the fi.lm the resulting oil spots are not visible on the screen; (b) Super-hardening the gelatin with substances such as formalin. Although this method tends to retard the softening of moist gelatin in a hot projector, the ' proce6S is non-lubricating; and (c) A large number of solutions of unknown composition have been pro- posed from time to time, but to date no practical tests have been forthcoming which indicate that such methods lubri- cate film more satisfactorily than a thin coating of paraffin wax or lubricating oil. To Summarize: The method of lubri- cating film by applying a thin coating of a 5 per cent solution of paraffin wax in carbon tetrachloride to the edges of film after development and previous to pro- jection is considered satisfactory. With film treated in this manner no visible accumulation of wax should appear in the projector gate even after seven or eight 1,000-foot rolls of film have been projected successively. If a visible accumulation of wax forms in the gate, then an excess of wax has been applied to the film and the projectionist should make the recommendation to the ex- change that a more dilute waxing solu- tion be used. Under normal conditions, a soft dark colored deposit will form in the projector gate. consisting of fluff, dirt, carbon dust, silver, and gela- tin which, normally, is removed easily by wiping after projection. If the film was not lubricated sufficiently, a hard in- crustation forms on the gate or the ten- sion springs which can be removed by scraping with a coin but never with a steel or iron instrument. SPECIAL P. A. C. MEETING IN NEW YORK MANY projection problems were con- sidered at a special midsummer meeting of the Projection Advisory Council which was held in New York City during the month. In addition, ex- tremely important matters of Council policy were discussed and agreed upon. The session, which ran for more than four hours, was presided over by Presi- dent Thad Barrows, president of Boston L.U. 182. The meeting was opened by P. A. McGuire, executive vice-president, who gave a brief resume of the activities of the Council during the past few months. It was pointed out by Mr. Mc- Guire that despite the limited budget of the Council for the present period, much beneficial work had been accomplished — work which he cited as laying the groundwork for valuable contributions to the craft in the future. Mr. McGuire also read the agenda for the session which he had opened. A resolution adopted at the session ad- vocated a greater interest by the Inter- national Alliance as an organization in the purely technical aspects of projection work and requested President Barrows to confer with the General Office of the LA. on the matter. Harry Rubin, Council treasurer, sub- mitted a report of finances covering the past six months, which .was accepted by the Board. Larry Jones, secretary, read several communications from British pro- jectionists requesting information on va- rious projectionist activities. Projectionist Interest Sought P. A. McGuire stressed the need for a wider interest among organized projec- tionists in the work of the Council and cited the desirability of a greatly in- creased membership. James J, Finn was appointed chairman of a special commit- tee to devise ways and means of effect- ing a closer contact between the Council and projectionist local unions through- out the country. ' The next general meeting of the Coun- cil will be held early in October. SUPERIOR CRAFTSMANSHIP IS BEST FIRE INSURANCE M. D. O'Brien ASSISTANT DIRECTOR OF PROJECTION, LOEW THEATRES, INC. One of Americans outstanding projection supervisors holds that safety in the projec- tion room, and consequent protection of an audience, depends not on preventives and fire-fighting apparatus but on you, Mr. Pro- jectionist, who oversee the equipment and direct the performance. MILLIONS of dollars are expended annually for the upkeep and maintenance of fire-fighting apparatus throughout the United States, yet millions of dollars worth of property is destroyed in the same period. Thea- tres, factories, garages, stores and simi- lar public places are equipped with fire- fighting apparatus. The various insur- ance and protective companies demand that approved fire extinguishers and sprinkler systems be installed. City, county and state officials insist that proper precautions be observed — that a certain number of fire exits, prop- erly equipped and strategically located, be provided. Automatic fire alarms, manually-oper- ated alarms and other fire-detecting sys- tems are employed. Even public and private firemen are stationed about pub- lic places to assure ample protection to the public. But with all this equipment, with all the signals and alarms and sprinklers and other extensive apparatus that is used, in addition to the employment of special fire officers, there is really noth- ing that can be said to prevent fire — that is, nothing that operates mechan- ically. The tremendous expenditure for protection against fire serves only to de- tect and to fight fire. So-called fire pre- vention devices do not prevent, but mere- ly hinder the spread of, fire.. Who Is Responsible? Particularly is this true of projection work. The projectionist himself is the most vital link in the chain of fire pre- vention in the theatre. Given the most up-to-date protective equipment, a thea- tre still is almost wholly reliant upon the projectionist for an adequate meas- ure of security. In the projectionist's hands lies the security of a theatre audience. His watchfulness, care in handling inflam- mable and combustible materials and his ability to visualize the tremendous importance of his position are the meas- urements of the degree of protection against fire existing in his theatre. All the fire-fighting apparatus and safety appliances in the world cannot prevent a careless person from dropping a cigarette or lighted match upon or near combustibles. All the signalling systems and alarms combined cannot prevent the practice of permitting dirt and refuse to pile up to such an extent as to constitute a fire hazard. A theatre has that degree of protec- tidii against fire that is reflected in the alertness and carefulness of the pro- jectionist. He is the one definite safety factor within the theatre — the one man upon whom everyone else in the theatre must rely for protection against fire. - Defective Equipment A projectionist should formulate and then religiously adhere to a fixed routine relating to protective measures. First and most important is the strict neces- sity for the exercise of the utmost care in handling not only film but every piece of equipment in the projection room. Next in importance is his duty to keep his equipment scrupulously clean and free from any substance or refuse which might constitute a fire hazard. All equipment should be kept in a constant state of repair. Worn and de- fective parts constitute a major fire hazard, and the projectionist who knowingly works with defective equip- ment is perpetrating an injustice upon the audience, which is in his safe-keep- ing, upon his employer, upon himself and his organization. To the projectionist's care is intrusted the care and handling of a great amount [11] of machinery which in itself presents no particular fire hazard. He is also en- trusted with the care of thousands of feet of film which may be said to be nothing more or less than readily com- bustible gun cotton. The latter does present a very definite and extremely formidable fire hazard. In reflecting upon some of the occur- rences within projection rooms, I have concluded that a majority of projection- ists permit their tremendous responsibili- ties to rest too lightly upon them. It shapes up as just a case of never giving the matter a thought, and one might very easily become lax and careless. After a fire it is too late to think about what might have been done. It appears that many of us are only too willing to believe that 'Tt never could happen to me." It can happen to any- one ; and the fact that is does happen is demonstrated by advices from the Na- tional Board of Fire Underwriters which show that four or five film fires are re- ported to its offices daily. Just think! every day four or five possible sources Canadian Film Fires THE following information was gathered by the Dominion Fire Marshals and Dominion Theatre In- spectors of all provinces, covering theatre fires which occurred in Canada during 1930 and 1931. The records fail to show any case where a projec- tion room fire spread beyond the pro- jection room itself. 1930 1931 British Columbia 7 4 Alberta 1 2 Saskatchewan 4 1 Manitoba 6 3 Ontario 17 7 Quebec 2 1 New Brunswick 0 0 Nova Scotia 1 0 Prince Edward Island.... 0 0 38 18- Figures relating to theatre fires in the United States are not available, al- though the National Board of Fire Un- derwriters receive '"four or five theatre fire reports daily". 12 INTERNATIONAL PROJECTIONIST July 1932 Just one item in the long list of fire hazards — and the type of equipment that no self-respecting craftsman would permit to be used of tragedy. Our attitude should be: "Tomorrow it might be me." The nature and the extent of damage done by a given projection room fire is of secondary importance. The fact that a fire occurs is our primary interest. Today's small and inconsequential fire might be tomorrow's tragedy. Accom- panying this article is an abstract from a report of a fatal fire which occurred sometime ago in Utah. It might be, it could be you. Regular Safeguards Film should be stored in the proper type of enclosure to insure against its coming into contact with an open flame or any piece of equipment the tempera- ture of which may be above that of the atmosphere. Film which is carelessly left lying about may be ignited from such sources as short-circuited wiring, unprotected rheostats (it has been known to happen) ; by pieces of hot carbon dropping from the lamphouse and, the records show, by strong sun- light beating through glass. We re- serve for last mention of that superior being who can smoke a cigarette while examining film. Such an idiot is nothing less than a criminal. When a film fire occurs in a projec- tion room today there is a reasonable assurance that it can be controlled to the point which little damage beyond the destruction of a few feet of film! will result. But . . . the audience knows nothing of our control procedure, and one little flame, one whispered word can result in tragedy which no amount of afterthought or fire-prevention equip- ment can repair. The history of our business proves that there have not been more than a half dozen film fires originating in pro- jection rooms which have done material damage to the other sections of the theatre. But there have been hundreds of fires originating in the projection room which have been the direct cause of thousands of fatalities — which is the thought uppermost in the mind of every projectionist worthy of the name. Dam- aged film is expensive, true. But it shouldn't be mentioned in the same breath with damage to human life. How many projectionists gaze out of the room ports and, surveying the audi- ence, are struck by the overpowering force of the thought: "These people trust me. They must, else they wouldn't be here"? Try it sometime. It will do your sense of craftsmanship, if not your soul, good. What are the best means for provid- ing against possible projection room fires? The answer is: just a few simple rules. Prevention Requisites In addition to exercising extreme care in handling film, keep your projectors in such mechanical condition that you never have to worry about whether they are functioning properly. This can best be done by constant inspection of the various parts — yes, even a daily inspec- tion is advisable. Look at your sprockets daily. Inspect the film shoes and tracks at least two or three times a day. Watch the take-ups. Keep the entire projector sufficiently well-oiled to permit of mini- mum wear of the gears and spindles. Replace worn parts before they have deteriorated to the point where they will damage film. Worn parts are the worst reflection on craftsmanship. Remember that damaged film, occasioned by worn Hollywood Brains "We have about five men in Hollywood who have enough knowledge of music, drama, litera- ture and graphic arts, to start shooting a picture. (Names on application.) All the other direc- tors could go back to school or kindergarten, as the case may be. "The only men worthy of praise in Hollywood as a class are the technicians — photographers, sound men, electricians, etc. Technically the craftsmen are ten years ahead of the alleged creative workers." Eric Knight, Philadelphia Public Ledger. parts, is the most likely source of danger from fire. Yes, film still ignites when piled up in front of the aperture. Repair and replace defective parts. Replacing defective parts is the highest form of fire prevention. A true crafts- man will not tolerate worn or defective parts; but if the craft instinct is not sufficient to force you into action, you might remember the presence in the theatre of several hundred, or more, people who come to your theatre be- cause they trust you. In addition to assuring mechanical perfection of your equipment, observe a rigid routine in cleaning your equipment and the projection room. Dirty sprockets, tension shoes and tracks cause many breaks and tears in the delicate fabric of the film. Such breaks may run through once or twice but eventually *7t Can't Happen to Me" THE following is an excerpt from an article which appeared in a recent issue of International; Projectionist\ The statement quoted is a verbatim transcript of the testimony of a theatre usher made at an inquest held to ascertain the cause of the death of a member of the Provo (Utah), Local Union:: "I was the first one to reach the scene of the accident, being attracted to the projection room by an explosion. As I remember, the accident occurred about 8:00 p.m. I rushed to the projection room and found it full of smoke. When I got there the door was closed, and I could hear shouts from within calling 'Help! Help! Ican't see.' Graham (the projectionist), managed somehow to open the door just as I reached for it. "I rushed into the room and as I faced him I could see he was burned from head to foot. His clothing was burned from his body and he kept crying out that he couldn't see. I took my coat off and put it around him; but he threw it off crying that he couldn't stand it. By this time he was burned beyond recognition. I finally succeeded in getting my coat around him and, with the help of an usher, took him downstairs to Dr. Arnold Robinson's office which was adjoining the theatre. . . ." ^ "A Model Form of Propaganda for Projectionist Unions,' International Projectionist, December, 1931, p. 31. by George A. Yager; July 1932 INTERNATIONAL PROJECTIONIST 13 they "catch up" with the careless man. Torn bits of film deposited in the bot- tom of the mechanism or lying loosely around the room make for a fine film fire. Debris which is permitted to ac- cumulate on the floor and in the corners of the projection and rewind rooms are at once an indication of what type of craftsman works in a given room and a source of great danger. "It Might Be You" To itemize each and every detail con- nected with a projectionist's daily routine would require more space than is available herein. The "punch" of this article lies in the emphasis placed upon the statement that fire prevention in a projection room depends absolutely upon the projectionist and not upon any par- ticular departmental ideas on fire-fight- ing apparatus or preconceived notions governing fire-eliminating equipment. Let each projectionist pay strict at- tention to the handling of film and let him keep in mind the fact that a per- fectly operating projector kept up to the highest standard of repair is worth a ton of fire prevention equipment. In closing we revert to the statement that few fires spread beyond the pro- jection room. This is true . . . but the projection room, and not the stage, hap- pens to be where the projectionist is stationed, and any trouble that results will naturally be handed out in large doses to that man who is handy — to you, Mr. Projectionist. Notes on the Auditory Response of the Human Ear THE normal human e^r has a tre- mendous range of auditory response. Over the band of frequencies from 500 to 2,000 cycles it will respond to the almost unbelievable energy range of one hundred million million to one — equivalent to 140 decibels in telephone terms. This range is bounded at the lower level by the intensity of sound that is just audible, and at the upper, by the intensity that becomes painful. The sensitivity is not alike at all fre- quencies, however. If the upper and lower limits of hear- ing were plotted on an absolute pressure scale both would curve: the upper con- vex upward, and the lower convex down- ward. For the purpose of studying hear- ing loss, however, it is convenient to em- ploy a straight base line and to indi- cate the range of pressure to which the ear will respond at the various fre- quencies as the curved line shown on Figure 1. When a person is hard of hearing, the range of pressure that he can hear is decreased, and the amount it is de- creased at the various frequencies can readily be indicated on a chart like that shown. The same base line may be re- tained but a new line, representing the person's range of hearing, is plotted from data secured with an audiometer. Such a curve is known as an audiogram, and Figure 2 gives such an audiogram for the two ears of a person we may re- fer to as Mr. A. As shown by this curve, a sound of 1,024-cycle frequency, which could just be heard by a person of normal hearing, would have to be increased 60 decibels, or sensation units, to be audible to Mr. A. Lower frequencies require less am- plification and higher frequencies, more. The audiogram of a person totally deaf would be on or below the broken line representing total loss of serviceable hearing. Because of the great range in both pitch and intensity that the ear pos- sesses, a person may lose part of the ear and not notice it. Our ears may not respond to some pitch ranges or to some intensity levels that are easily heard by 0 NORMAL HEARING-A. \ \ 1 ; / HEART MURMURS \ / / WHISPERS 40 60 \ / \ \ / / / 80 SPEECH ORCHESTRAL \ \ / / MUSIC \ / 120 V = )ERVICEABLE HEARING ^^~ .^ GUN FIRE Independent Dealers To Meet in Chicago THE Second National Conven- tion of the Independent Theatre Supply Dealers Associa- tion will be held at the Stevens Hotel in Chicago August 12 to 14, according to a recent announce- ment by President Joe E. Robin. Invitations to attend have been ex- tended to all manufacturers of the- atre equipment and supplies, and ample space will be provided without charge to any manufac- turer wishing to distribute his products. A unique feature of the Conven- tion will be the privilege accorded all manufacturers or their repre- sentatives to address the supply dealers either publicly or in pri- vate. Under the very able leadership of Joe Robin the Independent The- atre Supply Dealers Association has become an important unit in the theatre equipment field. Mr. Robin's extensive knowledge of the theatre field, coupled with his fine engineering talents and the de- sire to improve the service ren- dered by independent dealers, is reflected in the fast-growing pres- tige of the Association. — J.J.F. others, and yet he may not be conscious of the fact. When the hearing loss is about 35 sen- sation units, it becomes noticeable in conversation, especially with a group, and difficulty is experienced in hearing at a theatre or in some similar situation. When the loss is appreciably more than this amount, we become definitely con- scious of lessened hearing acuity. In noisy places we may still fare very well, however, since all voices are being raised. These and many other interesting facts have been gleaned by the technical staff of Bell Telephone Laboratories in the conducting of experiments to produce a satisfactory hearing aid. Such data are of more than passing interest to all those interested in sound reproduction in the theatre. 512 1024 2048 4096 8192 16384 PITCH ! 0 NORMAL HEARING-M ?0 \ \ \ 1 / / 40 Si. < U- J> / fiO \ \ -~ >""^ ^ ^ 1 80 \ \ '-^ L LEFT EA R / / 100 \ s RIGHT EAR / / i?o TOTAL LOSS OF 1 / , -^ SERVICEABLE 1 / ^C HEARING y 140 '"'-- — - y 51? 1024 204.a 4096 6192 PITCH Fig. 1. The auditory area. The curved line represents the hearing loss necessary at various frequencies to produce total deafness Fig. 2. An audios:ram for Mr. A whose hearing loss runs from about 40 db at 64 cycles to 70 db at 5,000 THE QUESTION OF SERVICE FOR SOUND SYSTEMS James J. Finn THE amount and cost of servicing sound reproducing equipments in theatres is one subject which no publication has had either the cour- age or the inclination to discuss. The reason for this hesitancy on the part of those otherwise exemplary scissor artists is obvious ... or must we tell? Costs and quantity of servicing are inseparably joined. The projection field is vitally interested in the amount of service; but costs also must be con- sidered. Let's first look into this matter of costs. "A graft", "a steal" and "an easy way to pile up millions for the electrics" are some of the descriptive phrases applied to the service charge. Forgetting for the moment certain other aspects of the matter, let us suppose that the implications contained in the fore- going statements are true. One com- ment immediately suggests itself: "What of it?" Exhibitors long ago were taught by film distributors that a thing is worth what it brings. Picture merchandising is based on that premise. Why, then, insist upon a complete change of tactics on the part of the so-called electrics? Question of Profits The question of profits derived by the electrics from the lease or sale of sound picture equipments has absolutely no connection with the cost of servicing those equipments — even though the in- come from service operations goes to make up a portion of those profits. Equipments were and are sold and leased at a certain figure. Service charges are based on so much service for a given type of equipment. If the exhibitor does not approve of the terms of sale or lease of sound equipment, he may do without. Harsh words, it may be said; but none the less expressive of *he situa- tion. By what right, real or fancied, does Mr. Exhibitor proceed to dictate to the electrics the limits of their profits? Does Mr. Exhibitor deny the legiti- macy of exploiting the new or novel on any basis deemed fit and proper by the possessor thereof? Did Mr. Exhibitor contribute to the cost of research, de- velopment, manufacturing, patent pro- tection and, finally, merchandising the sound picture equipment? Not one cent, Does Mr. Exhibitor say that, being the possessor of a rare animal having a po- tential worth of many thousands of dol- lars, he would sell the animal to a zoo or a circus for one dollar, simply because he wanted to help amuse the children? Nonsense. The right of the electrics to make that profit which they deem proper is as un- questionable as is the right of the ex- hibitor to change his program at stated intervals and ask of the same group of people another admission fee. Profits simply do not enter into the matter of service charges — or, at least, they should not. Frequency of Service Frequency of service is a question on which the electrics themselves are split. One camp holds to a certain number of inspection calls a month; while another camp, yielding to exhibitor pressure, in- stituted a policy of less service for less money. Service charges are of interest to pro- jectionists only because of their direct tie-up with the amount of service. But the amount of service is of vital im- portance to projectionists. Servicing, as applied to sound picture equipment, has its origin in the eco- nomic axiom that it is cheaper and more effective to prevent trouble than to cure it. This is especially applicable to thea- tres, where equipment trouble means not only replacements and repairs but also losses arising from refunded admis- sions, postponed performances and a dis- gruntled patronage. The very nature of show business justifies the policy of service as a pre- ventive rather than a cure. Showman- ship demands that every precaution be taken in advance of any possible trouble rather than that efforts be doubled to apply a corrective after the emergency has arisen. Show business is as remotely differ- ent from coal mining as is black from white, yet those who hold to the princi- ple of as little service as possible place show business in the same category as, for example, coal mining. A break- down at a coal mine means that no coal is mined for one day, two days or for [14] the duration of the breakdown. But after repairs are effected at a mine, double shifts of men can be put to work to mine sufficient coal to make up for the lag of production. Show business is not that sort of business. Theatre Income The breakdown of equipment in a theatre means that whatever patronage is lost during the period of inoperation is irretrievably lost — never to return. One minute, one hour, one day — it mat- ters not the extent of the shutdown — that period's business is lost and can never be regained. The business of the next day, the next hour or the next minute is business secured during that period only and cannot be applied to any other time period. Smart showmen recognize this pecu- liarity of their business, and that is why they offer little, if any, opposition to ample servicing operations. Why quib- ble about service charges when a re- duction of service may effect a loss dur- ing one day totalling three or four times the cost of a year's service? Those who are loudest in protesting the cost and quantity of sound picture servicing usu- ally are the poor showmen. Who, in either the sound equipment business or in the exhibition field, is capable of stating with authority the exact amount of servicing necessary foi a sound picture equipment? Let us assume that Exhibitor A concludes that his theatre need be serviced only once a month. The chances are very good that he could run along on this basis for two months, three months or even six months without encountering an emer- gency situation. But when his luck ran out (as he likely would express it), the one emergency call might cost him for equipment in refunds, loss of patronage and damaged prestige several times the amount of increased servicing. Inspection to Emergency Ratio That regular inspection calls have a very direct bearing on the number of emergency calls for a group of average theatres has been proven conclusively by the experience of at least one sound company. This being so (and figures prove that it is so), what intelligent showman can read such figures and still July 1932 INTERNATIONAL PROJECTIONIST 15 I opixise the policy dictated by their figures? All the discussion In the world cannot alter the fact that trouble-prevention is the goal of adequate servicing, and that the yardstick of measurement should be an equipment's freedom from breakdown and emergency needs. In the conduct of an adequate servic- ing plan efficient equipment operation has been sought and watchfulness in anticipating trouble has been a watch- word. Ever increasing experience on the part of engineers, more comprehen- sive testing equipment, broadened pro- jectionists' knowledge, improved and simplified equipment and the ability through organized approach of the prob- lem to spread and apply the advantages gained from each passing month's ex- perience have been important factors in the development of the result. Let's consider another analogy. Let's forget about the term "servicing" and think of the operation as insurance. Where lives that man who can accurately forecast that death will not overtake him between the ages of, say, 24 and 45, and who therefore concludes that it is fool- ish to pay insurance premiums during that period of his life? That man, if he be sane, probably doesn't exist. Yet the campaign for reduced servicing of sound picture equipment is the product of a reasoning even less intelligent and logical. Less Service Harmful If service charges can be reduced and the frequency of service maintained, all well and good. Operating costs is the answer to this problem. But a reduction of service charges for a reduced amount of service is a policy which should de- lude nobody and which should be op- posed by every projectionist, every exhibitor and every executive in this business. International Projectionist has been, and will continue to be in opposi- tion to any plan which embodies a re- duction in the amount of servicing given to sound picture reproducing systems in the theatre. Reduced service charges which entail a reduction in the amount of servicing surely is the easiest but hardly the sensible method of handling the matter. The present tendency on the part of exhibitors to neglect not only the sound equipment but the projection equipment as well reflects a misunderstanding of the first principle of show business: the show must go on. Exhibitors may be duped by the argument of "less ex- pense," but the exhibitor who follows such a trail inevitably comes a cropper. International Projectionist urges projectionists to exert their utmost in- fluence in the maintenance of an in- telligent and showmanly service policy. PROGRESS IN THE MOTION PICTURE INDUSTRY An Abstract of the Report of the Pro- gress Committee of the S. M. P. E. WHEN the new high-speed pan- chromatic films were first intro- duced about a year ago, cameramen used them chiefly for interior work. During the past six months they have been adopted quite universally for making ex- terior shots, so that it can be stated that the bulk of the pictures being made at W. E. Presses Unusual Patent Suit THE question of whether a pat- ented article can be used without authorization from or com- pensation to the holder of the pat- ent is raised in an unusual suit that has just been brought by the Western Electric Company against the operators of the Gibbs Theatre, Youngsville, Pa.; in the U. S. Dis- trict Court, Western District of Pennsylvania. Under the terms of the W. E. contract the sound projection equipment is leased for a period of years to an individual theatre. A transferral of equipment to an- other theatre, according to the con- tract, can be arranged only by mu- tual consent. The suit that has just been filed arises from the fact that a West- ern Electric equipment was in- stalled in the Strand Theatre, Greensville, Pa. When the opera- tor filed a voluntary petition of bankruptcy, the landlord seized the equipment. It was sold to the landlord's trustee at a sheriff's sale to go toward paying arreas in rent owed by the theatre operator. Subsequently it was bought by A. W. Gibbs and installed in the the- atre he operates in Youngsville. Western Electric's suit claims in- fringement of 29 patents. It con- tends that the equipment was leased to the Strand Theatre and licensed for use in that theatre only and that its unauthorized use in another theatre constitutes a violation of the Western Electric Company's patent rights. The action is the first of its kind to which Western Electric has been a party and involves some distinc- tive legal points, so that its out- come will be watched with close interest both by the motion picture industry and by members of the legal profession. the present time in American studios are being photographed on the new im- proved films. Commenting on the im- proved films, Hall reiterates the opinions previously expressed by cameramen that the significant property of the product is not so much the increased speed but the "tremendous improvement in photo- graphic quality . . ." obtainable by using the new film. New Materials. — A recent addition to the group of films is the Pankine G-Anti- halo film supplied by Agfa. According to Schilling, this film is said to be fine grained and to possess greater senstivity to red, yellow, and green rays than the older Pankine F film. A bluish green anti-halation layer is incorporated be- tween the emulsion and the support, which layer is unaffected by the process- ing solutions and necessitates only a slight increase in the printing light. Cheap Metal Film According to D. C. Dunham, Herr Kupfer has completed the development of an aluminum motion picture film band. Because the base is metallic, light must be reflected from it. Refin- ing the clarity of the reflection and achieving in the emulsion combinations that would adhere to the metal have been the two greatest difficulties encountered in completing the invention. In project- ing pictures from this metal-backed film, light from the arc is reflected from a mirror to the metal film as it passes over the projecting slot, the light falling on the film at an angle of incidence of 45 degrees. It is claimed that the film itself cost between one-fifth and one-sixth of the amount for the celluloid film, and it is also claimed that the metal is more dur- able than celluloid, does not stretch, and will not break so easily. It is claimed that the new film has been per- fected for sound and color reproduction. One hundred and thirty patents covering the production and reproduction of pic- tures from this film have been taken out in the various countries of the world. The Eastman Kodak Company has classified its panchromatic materials into three groups, known as Types A, B, and C. Group A includes materials of the same type as those made prior to 1931 ; group B materials, known as "orthopan- chrornatic," have an extremely high color-sensitivity, corresponding approxi- mately to that of the eye: group C mate- rials called "hyperpanchromatic." have a high total sensitivity, and are extremely sensitive in the yellow, orange, and red portions of the spectrum. Eastman su- (Please turn to page 25) VIBRATION: RELENTLESS ENEMY OF GOOD PROJECTION R, G, Hess VIBRATION has long been recog- nized as a serious handicap to good sound reproduction and to perfect projection of the motion picture. In addition to interfering with quality presentation of sound and picture, vibra- tion is an aid to wear and tear of all moving parts of a given equipment. Vi- tration isolation cannot be termed a new science, but its application to projection vibration problems is a matter of com- paratively recent date. For many years cork has been utilized in all general vibration isolation installa- tions. It is not denied that cork has served well its primary purpose, which is to ease the vibration; but it may be said in all truthfulness that cork has been tested and found wanting for isolation work. The special problems which came into being with this fast-moving age of daily scientific advances proved conclu- sively that moving parts of an equipment which was designed for hair-breadth ac- curacy required something better than cork as a protective against vibration. Such a substance is now available and is being merchandised in America under the trade name of "Keldur." What Is "Keldur"? Keldur was developed in Germany in 1918 as a synthetic rubber. Keldur re- sembles rubber in general appearance and characteristics, but is radically dif- ferent in several of its properties. Un- like rubber, it retains its resiliency over long periods of time, it does not oxidize or harden, and it does not "go dead." Among its very favorable characteristics is the fact that it is not affected by oil. Another outstanding Keldur charac- teristic is its pronounced "damping factor," or "time lag," in its reaction to vibration impulses, and it is this fea- ture which is responsible for its extreme efficiency in the absorption of vibration — a single %" thickness being from 85 to 100 per cent more efficient in this re- spect than is a 2" thickness of the very best natural cork available. For maximum efficiency when used for large areas an edge surface should be provided to permit the material to "give" easily under vibration impulses, and this is accomplished by breaking up the area into strips or by perforating with holes comparatively close together over the entire surface, as is indicated in the ac- companying diagrammatic representa- tions of typical installations. A single thickness of Keldur is highly effective under loadings of from 1 to 30 pounds per square inch; and in a double thickness up to 50 pounds per square inch, under frequencies ranging from single impacts up to 1,600 cycles per second. The actual carrying capacity of Keldur is in excess of 200 pounds per square inch, insuring a large factor of safety, particularly in consideration of the fact that the average loadings met with in vi- bration isolation practice range from 1 to 20 pounds per square inch, including the allowance for impact. Projection Applications ■ Keldur is manufactured in sheets 36" square, standard thickness being %", although it is obtainable in i^" and i/^" thicknesses for special applications. In no branch of the theatre field is the need for a product such as Keldur more pronounced than in sound and mo- tion picture reproduction work. Ac- ceptable sound reproduction means the elimination of all harmful vibration, and projectionists long have known that good projection requires steadiness of a pro- jector to an extent best described by the term "rock-bottom". The illustrations accompanying this article represent typical Keldur instal- lations as they have been made in the- atres operated by such well-known cir- cuits as Warners, Fox, Loew's, Publix, Randforce and m'any others, and are exactly correct in detail covering the in- stallation in the new Warner Theatre in Ridgewood, N. J. One of the first in the projection field to recognize the worth of Keldur as a vibration isolation material was Mr. Frank Cahill, of Warner Theatres; and in this company's new theatre in Ridge- wood, N. J., all mechanical equipment is isolated with Keldur. The unusual free- dom from vibration, and consequent clarity of sound and picture reproduc- tion, enjoyed by this theatre lends more (7) Z~sizd o^concrsie or 2'mxxiiia/Uei Tviib level foio. £a.j/er qfJ^eldury^'ib!lcmAs otieren- lire ^ojr/izce tzl ri^rifez'z^le.s lo ®. Sfri/s (^.Xeldiir, e'/vlcfe « ^'i6/cf, le/^rlS/vise ^.sel^ f/vo of £6ese' jsarallel to eaoi> olAer^ spaced ^^ as sbomn. irz ^ide elevafzo/z, O UoodjilojiA /i' ibleA ''e';!!ide,resi- i/zf orz^eldur s/rz>ie, (S), as, 3£own in .^zde eleoalton. fl/otes :J^olor^enjeraJor . 5/?/ rests o^ijalanAs (2)