International projectionist (Jan-Dec 1936)

30 INTERNATIONAL PROJECTIONIST October 1936 "INDEPENDENT"! . . . from a LOCAL institution 42 supply dealers in 27 cities throughout the country comprise the membership of this Association. The member nearest you is ready to share all the advantages which a nation-wide organization has to offer. And yet, his business is his own in every sense of the word. He is a local merchant with a keen appreciation of local projection problems. His skill and experience — his practice of carrying only standard, honest merchan s'^tFffflE SttM dise — are your assurance not '"" only of better service, but of square, ethical dealing! INDEPENDENT! INDEPENDENT THEATRE SUPPLY DEALERS ASSOCIATION 1501 BROADWAY J. E. ROBIN, EXECUTIVE SECRETARY NEW YORK CITY How Many? 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 coupon below. INTERNATIONAL PROJECTIONIST, 580 Fifth Ave., New York, N. Y. Enter my subscription for □ 1 year — 12 issues — $2.00 □ 2 years — 24 issues — $3.00 Foreign: Add 50c per year. Name Address City ... Slate the film are carefully controlled, and every endeavor is made to see that the customer receives the film under the best conditions for use. STABILITY OF MOTION PICTURE FILMS AS DETERMINED BY ACCELERATED AGING J. R. Hill and C. G. Weber National Bureau of Standards Motion picture film of the safety type shows great promise as a material upon which to preserve records of permanent value, according to tests made at the Bureau. This type of film, having a base of cellulose acetate, is designed for use where the highly combustible film of the ordinary theatre type, cellulose nitrate, presents too great a hazard from fire and explosion. In addition to its safety features, it appears to have the additional advantage of being much more lasting. Both types of film were studied by determining the effects of various accelerated aging treatments upon samples of new film. Samples of old nitrate were tested also to determine their condition after natural aging. The most satisfactory accelerated aging treatment found consists in heating the film in a dry oven, at 100° C, a test employed to find the relative stability of record papers. The films were tested for physical and chemical properties before and after oven-aging tests of various durations, and changes in the properties noted. High retention of folding endurance and viscosity, and small increase in acidity are considered indicative of stability. The acetate film was found to be excellent in these respects. Large losses in folding endurance and viscosity, plus large increases in free acid in the material characterized the changes in nitrate under the heat test. Its poor stability was further indicated by rapid change of resistance to an ordnance test used to determine the condition of smokeless powder. The cellulose acetate film withstood ovenaging for 120 days without serious chemical or physical changes, while the nitrate film deteriorated beyond usefulness after 10 days under the same conditions. The acetate appears to have lasting qualities comparable to those of permanent-record papers of high quality, and the optimal atmospheric conditions for the preservation of paper records are suitable for this film. Nitrate film is perishable, and its deterioration is ereatly accelerated under warm, moist conditions. The preservation of valuable nitrate film is a complicated problem involving both elaborate fire protective measures and airconditioning. FIRE PREVENTION IN THE MOTION PICTURE INDUSTRY H. Anderson Paramount Pictures This subject is extremely broad, since the motion picture industry embraces practically every known fire prevention problem. It is of the utmost importance, because of the combustible nature of motion picture film, the necessary consideration that must be given to safety of life in the operation of theatres, and the serious financial effect of the interruption of studio operations by fire. It is further complicated by the extreme susceptibility of sound recording and reproducing equipment and of finished motion picture film to fire and water damage. Motion picture exchanges have had an amazingly excellent fire record, the lowest fire loss record of any industry in the U. S. This is the result of the adoption of active fire prevention measures by the exchanges,