Numbers Don't Lie: 71 Things You Need to Know About the World

by Vaclav Smil

The conclusive experiment took place on June 19, 1878, at Stanford’s Palo Alto farm. Muybridge lined up thread-triggered glass-plate cameras along the track, used a white-sheet background for the best contrast, and copied the resulting images as a sequence of still photographs (silhouettes) on the disc of a simple circular device he called a zoopraxiscope, in which a rapid series of rotating stills conveyed motion. Sallie Gardner, the horse Stanford had provided for the test, clearly had all four hooves off the ground at the gallop. But the airborne moment did not take place as portrayed in famous paintings, perhaps most notably Théodore Géricault’s The 1821 Derby at Epsom, now hanging in the Louvre, which shows the animal’s legs extended away from its body. Instead, it occurred when the horse’s legs were beneath its body, just prior to the moment the horse pushed off with its hind legs.