On 19 June 1878, Eadweard Muybridge successfully photographed a horse named "Sallie Gardner" in fast motion using a series of 24 stereoscopic cameras. The cameras were arranged along a track parallel to the horse's, and each camera shutter was controlled by a trip wire triggered by the horse's hooves. They were 21 inches apart to cover the 20 feet taken by the horse stride, taking pictures at one-thousandth of a second. At the end of the decade, Muybridge had adapted sequences of his photographs to a zoopraxiscope for short, primitive projected "movies," which were sensations on his lecture tours by 1879 or 1880.