Thomas A. Edison, inventor of the motion-picture machine.
THE MOTION-PICTURE PROJECTOR
This is the standard Edison projector from two points of view, showing its complicated mechanism as clearly as possible.
One of the interesting points to remember about these films is that although they are made in lengths up to 400 feet they are all one and three eighths of an inch wide, and the three eighths of an inch is given over to a margin at each side of the picture. That leaves a width for each picture on the film of just one inch. The height of each picture is three quarters of an inch. Fancy a photograph one inch by three quarters of an inch! No matter how clear it is you could not see with the naked eye all its details, and so it is in the cinematograph picture. It is so clear and sharp that when put under a good magnifying glass details that cannot be seen by the human eye are noticed. Now fancy multiplying the area of each little picture 2,700 times, and think of the chance for magnifying imperfections! And yet that is the amount that each picture is magnified in throwing it on a screen of the average size.
The films are coated with the sensitive emulsion in two degrees. The negative films must be as sensitive as possible to light, as they are intended to receive the shortest possible exposure, while the positive films, or the ones which correspond to the print paper in still photography, are made less sensitive to light, inasmuch as they are exposed for a longer time in the printing machine.
Fireproof films are probably one of the most important developments in the whole great motion-picture industry, for through these, schools, colleges, churches, lecture halls, and other public places not fitted with the fireproof box in which the motion-picture operator works, can have the advantage of cinematography.