When was the photo-finish introduced to horse racing?

Nowadays, the photo-finish is an indispensable part of horse racing but, just over a century ago, the result of horse races was called by a judge who stood at the finish line. Many observers, including pioneering English photographer Eadweard Muybridge, noted the needed for the assistance of photography in horse racing and other sports. Indeed, in 1878, Muybridge had invented and demonstrated a means of photographing a horse in motion, but, according to Scientific American, the first documented use of a photo-finish in a horse race was in Plainfield, New Jersey in 1881. However, the original horizontal shutter often favoured a horse on the outside of the track and that problem was not solved until the invention of the so-called ‘strip camera’ by Lorenzo del Riccio in 1937. In Britain, the photo-finish was introduced by the Race Finish Recording Company, which now trades as RaceTech, in 1947, following a feasibility study by the Jockey Club.