Plateau continued by explaining that when the speed on one disk is not an exact multiple of the other they do not keep the same relative positions after rotation.
A different image is produced at each revolution and the eye, instead of seeing one fixed line (or image), sees only a rapid succession of different lines (or images); however if the swifter is little more than a multiple of the other, the difference is very little in a manner which the eye cannot distinguish one from another. In this case the spectacle will appear to change little by little....
There is the germ of the motion picture—a real instrument which makes pictures move.
The diagram illustrates a model in which “a perfectly regular image is produced from a deformed figure” turning in a speed proportional to the distortion behind the shutter disk.
Plateau pointed out that the deformed figure can be painted black and turn before a white surface, or be white and turn behind a slot pierced in a black disk. He said, “This last method is preferable to the other because it gives an image of greater lifelikeness....” This of course is the quality sought in all dramatic representations—realistic living pictures.
“For this effect,” he explained, “you design the deformed figure on white transparent paper and paint the surrounding space with a very opaque black, then make the experiment carefully, and place a strong light behind the paper.”
In the example shown in the drawing the two disks, mounted one behind the other, are rotated in an opposite direction, the motion of the deformed figure is double that of the shutter and the effect produced is that of the regular image shown in Figure 3.
Plateau then remarked, “The construction of these images is very simple.” He gave the method and an example. “While the shutter will be making a third part of a revolution all the points of the circle carrying the deformed figure will be present behind it and in consequence it will produce one regular complete image. Then during the second and third part of the revolution of the shutter it will be able to form itself into second and third images resembling the first.” These were the words Plateau used to explain the nature of the operations of the first movie machine.
He concluded: “As you are master of the production of the figures you can make them as bizarre and as irregular as you wish.” Producers of the modern motion picture have indeed made pictures that are both “bizarre” and “irregular.” Plateau would have liked modern motion pictures because he was fond of the theatre, especially liking comedies.
While Plateau was making the experiments in 1829 which led to scientific presentations of visual and optical phenomena as well as construction of the first motion picture machine to illustrate those principles as well as to entertain, a tragic event happened. Plateau in his investigations of seeing light and motion gave special attention to the chief source of all light on earth, the sun.