Motion Picture Herald (Jan-Feb 1936)

STARTLING IMPROVEMENT in SOUND is made by the NEW WRIGHT-DECOSTER Model 5900 Reproducer (formerly 309) with the revolutionary PAR/#CURVE in j/ \d HIGH FIDELITYX^ iIAPHRAGM • It eliminates sub-harmonics. • It helps eliminate high frequency can cellation. • It extends the range into the higher frequencies further than ever before possible. • Can be used with any equipment. Write for full information WRIGHT-DECOSTER, Inc. 2225 University Ave. St. Paul, Minn. Export Dept. — M. Simons & Sons Co., New York Cable Address: "Simontrice" Canadian Office— A. M. Flechtheim & Co., Guelph, Ont. THE MARK OF QUALITY GENUINE KAPLAN SURE-FIT PARTS have always been acknowledged the standard of quality and "interchangeable" with Simplex Parts. Their accepted superiority to other products lies in precision of manufacture. Write for catalog — All inquiries will be forwarded to our dealer in your territory. SAM KAPLAN MANUFACTURING & SUPPLY CO., INC. 729 SEVENTH AVE. NEW YORK, N. Y. managed and competently manned. Have heard hundreds of compliments expressed by regular customers and by transients during the years I have been connected with it, and that is, I believe, what tells the tale. We have Simplex projectors equipped with Strong reflector type light sources; RCA Photophone sound (PG-13) in a house seating 350. "As I said, this letter contains no questions. It is more in the nature of a letter of thanks or appreciation for the invaluable help your Comments and the Herald questions and answers have been to me. And now for another matter. "In the July 27, 1935 issue of Better Theatres, in your Comments, I read the announcement, made by 'Uncle Carl' Laemmle of Universal, that he would pay $50 for any suggestion from any projectionist that seemed to have value for improvement in Universal film. In September I had a brain storm, sent in a suggestion, and on November 10 back came a perfectly good check for $50 and a letter from Mr. Laemmle himself. And believe me, Mr. Richardson, I am certainly proud of that letter. As for the money, I feel that you deserve the credit more than I do and I wish I might adequately express my sincere gratitude. Words are not at all adequate, though, but maybe the Bluebook order will anyhow help a little." Brother, you owe nothing to me. I do my job and try to do it well. If you do your job well, as it seems you do, that is the best form of gratitude you can show me. It was you who had the energy and ambition to act on Mr. Laemmle's offer. SCREEN WIDTH AND GOOD VISION F. L. bryant of Durant, Oklahoma, writes, "In a recent discussion there was much uncertainty as to just what is best, so like the good parson turns to his Bible, we turn to you. The company we work for is building a new theatre in which the architect's plan calls for a screen 20x15 feet. Auditorium dimensions are 72 feet from screen to last row of seats below, and 92 feet to last row in balcony. Screen to front row of seats, 16 feet. Width of auditorium, 48 feet. Proscenium opening, 30 feet. "Possibly I am wrong, but according to my views a 20-foot screen is too large. It could and should be much smaller. Please set forth the dope in this matter. My heartiest congratulations for the wonderful work you are doing. May 1936 be even better to you than you hope for." Thanks, brother. Space is restricted, so let's get at the problem. You are perfectly right. Your company would do well to cut down the size (width) of that screen image to, at the very most, 18 feet. Sixteen would be still better. What sort of view is going to be had of a 20-foot screen image by people in those front seats — especially the end ones? And what purpose does this large size serve ? A well illuminated 16-foot screen image will be perfectly visible in all its details to all persons of normal eyesight at 92 feet, and it will appear very much better to those in the front part of the auditorium than would one 20 feet wide. The commonest kind of common sense should tell any one that a reduction . of size will improve the appearance of a . screen image from the front part of the theatre — any theatre. The only question, then, is can all picture details be seen from the rear seats, and you may take it from me they can in this case, always assuming the screen to be well illuminated — not overilluminated, but with, say, 13 foot-candles at the screen center. And is it not perfectly plain that with equal light on both, the 16-foot screen image will be far more brilliantly illuminated than would the 20-footer. Given a certain amount of total light, in one case it must be spread over a very much larger area than in the other. You can figure it out for yourselves. Architects, no matter how capable they may be in planning theatres, are expert in projection problems, yet they too often go right ahead and stipulate picture size, etc., which is often accepted and a great deal of damage done. OPERATION INDUCTION OF MOTORS JOHN C. BALLINGER of St. Paul, Minn., asks, "Will you be good enough to explain, in detail, the application of power by induction as applies to electric motors? I have examined electric text books, but find myself unable to understand the very complicated explanations therein contained." That is the trouble with too many text books. The book and its text usually is quite all right, but all too often of little or no value to any except men with technical training, which is something the great majority of theatre men lack. However, I fear the question you ask cannot be completely answered in any very simple fashion. Many different people have written complete volumes in explanation of the various characteristics of induction motors. It is therefore obviously quite impossible to enter into any comprehensive analysis of the matter in my Comments. Moreover I believe that did I attempt any such thing, it would only serve to confuse you and call down upon my head the very just criticism you have made of text books. I believe you come mostly into contact with Avhat is known as "squirrel cage" induction motors. I shall answer the question along the lines suggested by the Westinghouse engineering department, Pittsburgh, Pa. Whenever a voltage is impressed upon a coil, current flows in that coil, and that current causes a magnetic field to be produced. In polyphase induction motors the line voltage is connected to a series of coils in the stator, and these coils are so connected together and to the line that the resulting magnetic field tends to rotate around the rotor. If a magnetic field cuts or moves across 30 Better Theatres