The Horse in Motion

In 1873,[9] Stanford approached Muybridge to photograph his favorite trotter Occident in action. Initially Muybridge believed it was impossible to get a good picture of a horse in full motion. He knew of only a few examples of instantaneous photography made in London and Paris, that depicted street scenes in very practical conditions, with subjects moving towards the camera no faster than the ordinary walk of a man, in which the legs had not been essayed at all. He explained that photography simply had not yet advanced far enough to record a horse flashing by the camera. Stanford insisted and Muybridge agreed to try.[7] The first experiments were executed over several days. To create the needed bright backdrop, white sheets were collected and Occident was trained to walk past them without flinching. Then more sheets were gathered to lay over the ground so the legs would be clearly visible, and Occident was trained to walk over them. Muybridge developed a spring-activated shutter system, leaving an opening of 1/8 of an inch, and in the end managed to reduce the shutter speed to a reported 1/500th of a second.[9] Nonetheless, the best result was a very blurry and shadowy image of the trotting horse. Muybridge was far from satisfied with the result, but to his surprise Stanford reacted very enthusiastically after carefully studying the foggy outlines of the legs in the picture. Although Stanford agreed that the photograph was not successful in regard to image quality, it was definitely satisfactory as proof for his theory. Most of the previous depictions and descriptions had indeed been wrong. Before leaving his customer, Muybridge promised to concentrate his thoughts on coming up with a faster photographic process for the project.[7] Although Stanford later claimed he did not contemplate publishing the results, the local press was informed and it was hailed as a triumph in photography by the Daily Alta California.[9] The image itself remained unpublished and has not yet resurfaced.

Occident. Owned by Leland Stanford. Driven by Jas. Tennant. (1877 cabinet card)

Over the next few years, Muybridge was occupied with other projects, often travelling to distant places, and with the trial for his murder of the lover of his wife. After his acquittal on the grounds of justifiable homicide, he traveled through Central America for nine months. Eventually, he returned to California and teamed with Stanford for a new attempt at capturing an image of Occident at full speed.

In July 1877, Muybridge worked on a series of progressively clearer, single photographs of Occident, at a racing-speed gait[10] at the Union Park Racetrack in Sacramento, California.[11][12] 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.[13] Lantern slides of the trotting horse photographs survive.[14]

Stanford financed Muybridge's next project: to use multiple cameras to photograph a thoroughbred at a gallop at Stanford's farm in Palo Alto. On 15 June 1878, in the presence of the press,[15] Muybridge photographed the businessman's Kentucky-bred mare named Sallie Gardner running.[16][17][18]

Plate CVI from Stillman's The Horse in Motion, showing Muybridge's arrangement of 24 cameras for instantaneous photography

He had arranged the cameras along a track parallel to the horse's path. Muybridge used 24 cameras[19] which were 27 inches (69 cm)[20] apart. The shutters were controlled by trip wires triggered by the horse's legs. The photographs were taken in succession one twenty-fifth of a second apart, with the shutter speeds calculated to be less than 1/2000 s. The jockey Domm set the mare to travel at a speed of 1:40, which meant that she was galloping at a mile per 1 minute and 40 seconds, equivalent to 36 miles per hour (58 km/h).[21][22] Muybridge produced the negatives onsite; when the press noticed the broken straps on Sallie's saddle in the negatives, they became convinced of the prints' authenticity. The images showed the mare lifted all four legs off the ground at certain points during the gallop..

While there have been rumors that Stanford had a large bet riding on the suspected outcome that the study would show that a horse at moments has all legs off the ground when running, the historian Phillip Prodger has said, "I personally believe that the story of the bet is apocryphal. There are really no primary accounts of this bet ever having taken place. Everything is hearsay and secondhand information."[23]

The photographs showed that all four feet are indeed sometimes simultaneously off the ground, and that when galloping this occurs when the feet are "gathered" beneath the body, not when the fore and hindlimbs are "extended" as sometimes depicted in older paintings.