Hausenstein spoke a great deal that night, and not only about the art of automatons. Not all of what he said made sense to August, for Hausenstein, despite his gift of exact criticism, was given to the spinning of elaborate theories, but one idea did make a strong impression on him. Hausenstein maintained that the nineteenth century was above all the century of motion. By this he did not mean simply, or even primarily, that the age was obsessed with speed: frankly, trains bored him, though this did not prevent him from seeing their spiritual significance, and incidentally there was a rather nice description of a moving landscape watched from a train in a little poem by Verlaine in La Bonne Chanson which was probably the first description in French verse of this very modern phenomenon. Someday he would perhaps write a little paper comparing such descriptions with earlier ones of landscapes glimpsed from coaches. But trains were only a crude expression of the century’s love of motion, which was far more strikingly expressed in its arts and entertainments. The new painters in France, for instance, might speak as much as they liked about sunlight and chromatic values; what struck an observer above all in the curious products of l’impressionisme was the sense of leaves stirring, of reflections rippling, of air trembling—it was an art consisting entirely of shimmer and vibration, of solid things broken into trembling points: sunlight as motion, the universe as nothing but motion. But such effects were capable of only a moderate development and would inevitably be replaced by the far more compelling illusions of motion that the century was already developing in its popular entertainments. Photography, that characteristic invention of the age, was considered by many learned gentlemen to have driven painting into the excesses of the modern school, but these same gentlemen would do better to realize that l’impressionisme was merely one expression of a much wider tendency. More than a decade before Daguerre displayed his first light-picture in 1839, a far more important discovery had been made in the realm of optics. It was discovered that an image cast onto the retina remains there for a fraction of a second after the object is removed. This profoundly significant phenomenon—surely August had heard of persistence of vision?—had been demonstrated by means of an ingenious toy. It was called the thaumatrope, and was no more than a small paper disk with a different image on each side: a bald man on one side and a toupee on the other, a parrot on one side and a cage on the other. Strings were attached to the opposite ends of the disk to permit twirling. When the disk whirled about, the two different images merged into one: the bald man wore his toupee, the parrot sat in the cage. But the thaumatrope, while demonstrating the principle of persistence of vision, did not present the illusion of motion. It was in 1832 that Monsieur Plateau invented his phenakistoscope, lovely name, that slotted disk attached to a handle and spun before a mirror. On one side of the disk a number of drawings were arranged in phase, and when the disk was rotated before the mirror, the reflected image viewed through the whirling slots became a single continuous motion: the little girl skipped rope. Thus was born the moving image, which already in this crude and childish form surpassed the effects of the clockwork pictures of the previous century. There had followed a stream of charming and ingenious toys, each improving the illusion of motion and each bearing a splendid name—but he would not bore August to death with descriptions of the zoetrope, the praxinoscope, and other such toys of genius. He would mention only that as early as mid-century the magic lantern had been combined with one of these devices to project moving images on a screen. And at this very moment, in Paris, the brilliant Emile Reynaud, using his own praxinoscope, was projecting colored moving pictures onto a background cast by a second projector. These pictures were all of course painted by hand, but it was only a matter of time before the photograph itself—that authoritative illusion—would be used in place of the hand-painted picture. Indeed, serial photographs had already been invented across the ocean, in dear old America; it remained only for some sublime tinkerer to discover a practical way to produce and project them. Then a new art would be born, and the century’s striving for the illusion of motion would at last be satisfied. It was amusing that Daguerre, the inventor of light-pictures, had also invented that hoary popular entertainment the Diorama, which had drawn large crowds early in the century with its quite different illusions of motion, produced by ingenious lighting effects, and doomed to extinction. L’impressionisme, the Diorama, pictures that move—these were the inventions that he found far more revealing than the railroad and the dynamo, for in these arts the century’s love of motion had invaded a medium that by its very nature was motionless.