For hundreds of years, prior to photography, people debated how a horse ran. Did all 4 feet leave the ground at once? Or were some always touching?

The photographs showed that all four feet are 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.

“ It was shown that the supposed superior grace of the horse while running is in reality a delusion: that the feet are gotten into all sorts of queer positions.”