Those of us who have witnessed the marvelous development of the great motion picture, who have perhaps played in our childhood with the strangely named toys, which produced the crude effects of movement of a few printed figures on a short strip of paper, have lived through the most astonishing drama of all that the moving picture has produced. Its own development to one of the principles of the world is a great romance. It is a romance told by thousands of films all over the world; every film is a short chapter in the great story. The modern motion picture projection machine has grown up from the old tin magic lantern. It has become a marvel of mechanical perfection. Every movement is precise. It deals with minute quantities, which are magnified to colossal dimensions on the distant screen, establishing a condition for showing the smallest error or imperfection in the mechanism. The projection of the minute film picture is a severe test for the mechanism of the projection machine. This is the perfection of the mechanism. Other things are to be noted. The optical system is to be of the best. A picture smaller than a postage stamp is magnified to the width of twelve or fifteen feet and the lens maker has to exercise his best skill to secure a flat image with no trace of aberration. The intermittant movement has to be as precise as the mechanism of the dividing engine. When the Swiss watch makers developed the stop-movement to protect the mainsprings of their watches, they could not foresee the role it was to play. For on it depends the production of moving pictures all over the habitable world. Electricity appears also in the work. The operator no longer has to turn the wearying crank for hours at a time. Electricity does it for him. The projection of motion pictures is a process involving the perfection of mechanics, of optics, and of electricity.