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The 'Experiment Track' at Palo Alto Stock Ranch
13.8 x 23.2 cm
Royal Academy of Arts
Photo: R.A., © Copyright protected
The sixth of six introductory illustrations from Eadweard Muybridge, The Attitudes of Animals in Motion (London, 1881).
Plate F. 'General view of the experiment track, background and Cameras. Threads are being stretched across the track, 12 inches apart, and at a suitable height for photographing the action of a running horse. One end of each of the threads is secured in front of the Cameras, hauled taut, and fastened to a metal spring, which is drawn almost to the point of contact with a metal plate. In its progress over the track, the animal strikes these threads in succession, and as each spring touches its metal plate, a current of electricity is sent through a connecting wire to the magnet in the shutter opposite, and exposures of the plates in the line of the Cameras is successively made, each exposure recording the position of the animal at the instant of his pressing against its corresponding thread; this accomplished, the thread immediately breaks. For horses driven in vehicles the exposure is made by steering one of the wheels over wires, slightly elevated from the ground, the successive depression of each one completing an electric circuit, and making its corresponding exposure.
For recording the movements of animals not under direct control, clock-work apparatus is arranged to cause successive exposures at regular intervals of TIME instead of uniform distances. The boxes, arranged in a semi-circle contain Electro-shutters and Cameras, for obtaining simultaneous exposures of the same position of the animal from different points of view.'