Light Visible and Invisible

Source: Silvanus Thompson, Light Visible and Invisible: a series of lectures delivered at the Royal institution of Great Britain, at Christmas, 1896, with additional lectures (London: Macmillan, 1912, 2nd ed. [orig. pub. 1897]), pp. 97-99

Text: Another example of effects produced by persistence of the optical impressions in the eye is afforded by an old toy, the zoetrope, or wheel of life; in which the semblance of motion is given to pictures by causing the eye to catch sight, in rapid sequence, through moving slits, of a series of designs in which each differs slightly from the one preceding. Thus if you want to make the sails of a windmill seem to go round, the successive pictures must represent the sails as having turned round a little during the brief moment that elapses between each picture being glimpsed and the next being seen. These intervals must be less than a tenth of a second, so that the successive images may blend properly, and that the movement between each picture and the next may be small. Mr. Muybridge has very cleverly applied this method to the study of the movements of animals. Anschutz’s moving pictures, illuminated by intermittent sparks, were the next improvement. And the latest triumph in this development of the subject has been reached in the animatograph, which the inventor, Mr. R. Paul, has kindly consented to exhibit.

The animatograph pictures are photographed upon a travelling ribbon of transparent celluloid; the time which elapses between each picture being taken and the next being about one-fiftieth of a second. A scene lasting half a minute will, therefore, be represented by about 1500 pictures, all succeeding one another on a long ribbon. If these pictures are then passed in their proper order through a special lantern, with mechanism that will bring each picture up to the proper place between the lenses, hold it there an instant, then snatch it away arid put the next in its place, and so forth, the photograph projected on the screen will seem to move. You see in a street scene, for example, the carts and omnibuses going along; the horses lift their feet, the wheels roll round, foot passengers and policemen walk by. Everything goes on exactly as it did in the actual street. Or you see some children toddling beside a garden seat. A big dog comes up, and the boy jumps astride of him, but falls off, and rises rubbing his bumps. Or a passenger steamer starts from Dover pier: you see her paddles revolve, the crowd on the pier wave farewells with handkerchiefs or hats, the steamer wheels round, you see the splash of foam, you note the rolling clouds of black smoke proceeding from her funnel, then she goes out of sight round the corner. The reality of the motions is so great that you feel as though you had veritably seen it all with your own eyes. And so you have. You have just as truly seen the movements of the scene as when you have listened to the phonograph you have heard the voice which once impressed the record of its vibrations. Of all the animatograph pictures those that appeal most to me are the natural scenes, such as the waves rolling up into a sea-cave and breaking on the rocks at its mouth, and dashing foam and spray far up into its interior. Nothing is wanting to complete the illusion, save the reverberating roar of the waves.

Comments: Professor Silvanus Phillips Thompson (1851-1916) was a British professor of physics and member of the Royal Society. The above passage comes from a series of lectures Thompson gave at the Royal Institution over Christmas 1896. The Animatograph was a projector produced by British engineer and film producer Robert William Paul. The films mentioned include Children at Play [no.1] (1896, frmes reproduced here from Thompson’s book) and A Sea Cave Near Lisbon (1896).

Links: Copy at Hathi Trust