"Did the pictures move very much?" he asked with a smile.
"Of course they did. They moved all the time."
"No, they only seemed to move, for as a matter of fact there are no such things as 'moving pictures.' We call them 'motion pictures' now, for that comes nearer to expressing the idea.
"Cinematography, which is the technical name for the whole art of motion pictures, is based on one of nature's defects, whereas most inventions are based on some of nature's perfect processes. The defect is called by the scientists the persistence of vision, which means that after you look at an object, and it is quickly taken from before your eyes, the image remains there for the fraction of a second.
ELECTRICITY ENOUGH TO KILL AN ARMY PERFECTLY HARNESSED
The Oscillator shown on the left sending an alternating current from the earth into a large reservoir and back at the rate of 100,000 oscillations per second causes the tremendous electrical explosions as the reservoir is filled each time. The flames in this experiment were 22 feet long.
