The Optical Lantern and Cinematograph Journal (Nov 1904-Oct 1905)

THE OPTICAL LANTERN AND CINEMATOGRAPH JOURNAL. 251 repay all the labour ; and a more fascinating pursuit than the use of this beautiful instrument, and the study of the objects which it is so well calculated to display, it would be difficult to imagine, as every one who has ever tried it for himself, and concentrated the powers of his intellect upon it, knows better than any words can express. •S -? FIRES FROM MOVING PICTURE EXHIBITIONS. [Abstracted from the Scientific American.] THE danger attending the use of moving picture apparatus is due to the highly inflammable character of the celluloid film bearing the pictures, and to the intense heat produced where the light is condensed upon the film. This heat is sufficient to ignite the film at the projection aperture if the light is allowed to rest continuously upon one portion of the film for a few seconds ; but when the machine is in operation, the film, of course, travels so rapidly across the projection aperture that the heat is without effect upon the film. The projection aperture, therefore, is the point at which the film is most apt to take fire, and in almost every instance the ignition takes place because a portion of the film is held stationary at the projection aperture for a time. CONTRIBUTORY CAUSES This may be brought about in various ways. The film may break below the projection aperture ; the feed mechanism may become jammed and inoperative ; it may lose its hold on the film ; the crank may become loose on the shaft of the feed mechanism so that its turning will not feed the film forward ; a small fragment may be torn off the film and lodge in the projection aperture, where it will be exposed to the full heating effect of the light ; or the operator may stop turning the crank of the film feed mechanism for any one of a variety of reasons. He may become faint or giddy from the heat or from escaping gas; his attention may be suddenly distracted, and he may forget to keep the film feed mechanism in motion ; or he may stop the feed of the film intentionally and neglect to cut off the light. PREVENTIVE MEASURES. Fires have resulted more than once from each of the foregoing causes, and it is practically impossible to construct moving picture apparatus in such a way as to prevent the film from occasionally taking fire at the projection aperture. It is possible, however, to prevent serious consequences from the ignition of the film at this point, and this may be done by simply preventing the fire from following the film from the projection aperture to the reels upon which the film is wound. Ordinarily, these reels have from eight hundred to twelve hundred feet of film wound on them, consequently, if a flame reaches either of these reels, the fire that results is so large, so hot, and so difficult to extinguish, that great damage to the building is almost certain to result, to say nothing of the panic that is always caused when a flame of any size breaks out in a place of public entertainment. If, however, the film burns only at the projection aperture, the flame will be small and do no damage. LIMITING THE FIRE AREA, To limit any fire that may occur from a moving picture exhibition to a few inches of the film, it is only necessary to inclose both the film supply reel and the take-up reel in fireproof chambers, and to provide valves leading into said chambers through which the film can pass freely while the film feed mechanism is in operation, but which will close instantly when the film feed mechanism ceases to operate or the tension upon the film is relaxed. If the film supply reel and take-up reel are inclosed in such fireproof chambers or magazines, the ignition of the film at the projecting aperture is a matter of very little consequence, as the burning of the film at that point immediately causes a reduction of the tension on the film, and permits the valves through which the film passes into the magazines to close, and so prevent absolutely the passage of the flame into the magazines. Properly constructed magazines for the film supply reel and take-up reel can be applied at very small cost to any moving picture machine, and if the machine is equipped with such magazines, it may even be overturned without causing any serious damage.