All About Inventions and Discoveries
The Romance of modern scientific and mechanical Achievements

330 All About Inventions requirements, and success in this direction is entirely attributable to two diligent American workers, Messrs. Walker and Eastman. They finally prepared a cellu- loid base, as it is called, which, when covered with the sensitised emulsion, could be employed either for negatives or positives. The perfection of this idea served as the key to another problem upon which they had long been engaged. This was the perfection of a camera in which the pictures, instead of being taken upon single glass plates, might be received upon a length of celluloid, and in such a manner that, after a picture had been taken, the exposed section might be wound on a drum to bring a succeeding area of the unex- posed surface into position for exposure. It appeared a simple problem, but as a matter of fact it was one bristling with baffling perplexities. But perseverance brought its due reward, and in 1888 appeared the first camera of this type with roll holders carrying a sufficient length of film for one hundred exposures. Eastman’s apparatus, which to-day is universally known as the “ Kodak ” camera, naturally suggested animated photography. If a length of film could be introduced into a camera capable of receiving one hundred successive pictures of the accepted size, why could not the camera be adapted to take a length of film sufficient to receive several hundred pictures of smaller dimensions ? This was the issue as it occurred to Edison, who forthwith reduced his idea to practice. Although he succeeded, it was quite apparent that his invention was based upon the Kodak camera, which was capable of being adapted to the self-same duty with certain slight modifications. Indeed, it is