Sallie Gardner at a Gallop

Sallie Gardner at a Gallop, also known as The Horse in Motion, is a series of photographs consisting of a galloping horse, the result of a photographic experiment by Eadweard Muybridge on June 15, 1878. Sometimes cited as an early silent film, the series and later experiments like it were precursors to the development of motion pictures. The series consists of 24 photographs shot in rapid succession that were shown on a zoopraxiscope. Muybridge was commissioned by Leland Stanford, the industrialist and horseman, who was interested in gait analysis. The purpose of the shoot was to determine whether a galloping horse ever lifts all four feet completely off the ground during the gait; at this speed, the human eye cannot break down the action.

Leland Stanford had a large farm at which he bred, trained and raced both Standardbreds, used for trotting races in which a driver rides in a sulky while driving the horse; and Thoroughbreds, ridden by jockeys and raced at a gallop. He was interested in improving the performance of his horses of both types and in the scientific questions of their gait action.

During July 1877, the photographer Muybridge tried to settle Stanford's question with a series of progressively clearer, single photographs of Stanford's trotter, Occident, at a racing-speed gait at the Union Park Racetrack in Sacramento, California. He captured the horse in a photograph with all four feet off the ground. One of the prints was sent to the local California press, but because they found that the film negative was retouched, the press dismissed it. As negative retouching was an acceptable and common practice at the time, the photograph won Muybridge an award at the Twelfth San Francisco Industrial Exhibition. Lantern slides of the trotting horse photographs survive.

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