One set corresponded exactly to the distances of the pictures and the result was that the moving object appeared to remain on the same spot.

The second brought the slits nearer together; then the pictures necessarily produced an effect as if the man were really moving forward while he performed his tricks.

In the third set the slits were further distant from one another than the pictures, and the result was that the picture moved backward.
The scientific principle which controls the moving picture world of today was established with these early devices.

Isolated pictures presented to the eye in rapid succession but separated by interruptions are perceived not as single impressions of different positions, but as a continuous movement.

But the pictures of movements used so far were drawn by the pen of the artist.