By 1878, Muybridge had successfully photographed a horse in fast motion using a series of fifty cameras. The cameras were arranged along a track parallel to the horse's and each of the camera shutters was triggered by electronic timers developed specifically for the project. The resulting series of photos proved that the hooves do all leave the ground at the same time --- although not with the legs fully extended forward and back, as artists of the day had imagined, but rather at the moment when all the hooves are tucked under the horse, as it switches from "pulling" from the front legs to "pushing" from the back legs.