The New Arc Lamp
“The films then had one perforation on either side of each picture. That was the French method. The American method of four perforations on either side of each picture, formulated by Thomas A. Edison, was taken up later. The Edison perforation method became the standard in America and finally throughout the world. We find no more single-holed films.”
Here, for the benefit of the uninitiated, a little description of the film and the projecting head of a machine is necessary. A motion-picture film is a thin ribbon of transparent pyroxylin plastic or nitrocellulose, which is highly inflammable. The photographs on the film, one by three-fourths of an inch in size, leave a margin of five thirty-seconds of an inch on each side. In the margins are the perforations necessary to feed the film through the machine head. There are sixteen pictures to the foot.
The mechanism of the machine head moves the film over an aperture, so that the rays of light from the lamp will project an enlargement of the film picture upon the screen. The reels upon which the film is wound are mounted above and below—the upper is the feed reel and the lower is the take-up reel. Sprocket wheels control the action of the film. The top feed sprocket pulls the film from the upper feed reel, the middle intermittent sprocket (below the aperture) turns in a way to give each picture a certain time of stop over the projection aperture, and the bottom take-up sprocket assists in winding the film on the take-up reel.
Narrow Shutter Wings Afford Brighter Illumination on the Screen
“The early films were in very short lengths,” continued the manufacturer. “The average was from twenty to seventy-five feet. A hundred-foot film was considered extra long. They were mostly comic and not educational. The vast possibilities of the film had not yet dawned upon the pioneers. They aimed only to get a laugh with a crude comic picture.
“But those with more foresight realized that the film had come to stay. So the advancement began. Today the public is always looking toward something better. It has been educated up to an exceedingly high standard. The average spectator today can see a defect in an exhibited film as quickly as an expert.
“Machines in the early days were very crude, permitting only short films, which were an endless belt. They were threaded over spools contained in a box at the rear end of the lamphouse, passing over the lamphouse to the head of the machine; thence down through the head, past the projection aperture and back to the spools. This exposed the film at all times, which was extremely dangerous. About 1900, longer films came into use, which necessitated a change in handling. At the machine head, the film was piled on the floor. This being dangerous and destructive, a receptacle was devised and fastened to the frame below the reel, into which the film passed. This soon gave way to a reel known as the take-up reel, which received the film after it had passed from the upper reel through the head and before the aperture, where it was projected on the screen.
“These are a few steps in the march towards improvement. My first machine was called the ‘Peerlesscope.’ I kept continually improving it, and in 1902 changed the name to ‘Cameragraph;’ my latest machine, No. 6B, possesses every known device for safety—fire-shutters, which automatically cut off the film from the rays of the lamp while motionless; film-shields, which enclose and protect the film; fire-valves, which prevent entrance of flame into magazines; the loop-setter, which prevents breakage of the film while in motion, etc.”