Part of the Horse exhibition.
Having four legs, instead of two, makes it possible to move your feet in a variety of different patterns, or gaits. Humans can walk, skip and run; horses naturally walk, trot, canter and gallop. In addition, horses can be trained to a dozen other distinct gaits. Each gait is most efficient at a particular speed. The walk is best at slow speeds, but awkward at higher speeds. To move faster, a horse "switches gears" to the trot, and at top speed it shifts to the gallop.
Every gait has a distinctive pattern of leg movements-in some, only one foot leaves the ground at a time, while in others, multiple feet do. Because of the speed of gaits like the gallop or canter, for years people could only guess at these leg patterns. But in the 1870s, British photographer Eadweard Muybridge captured the horse midstride in a historic series of photographs, some of which are on display in the exhibition. The same photos can be seen in motion in a spinning zoetrope on exhibit.
Spin and Look In
When you look through the slots of the spinning cylinder, you can watch horses using three different gaits: the gallop, trot and walk. The images were taken in the 1870s by Eadweard Muybridge, who was famous for taking freeze-frame images of animals and people in motion. When you spin the wheel, the images seem to come to life.
Until the 1870s, no one was sure whether all the hooves of a trotting horse left the ground at the same time. Look closely at the fifth frame of this Eadweard Muybridge sequence and you can see that all four legs are indeed off the ground at once.
The legs of a trotting horse always move in pairs, with each leg mirroring the motion of the one diagonally opposite. In a gait called the pace, the motion of the legs is very similar to the trot, except the front and rear legs that move together are on the same side.
In the gait known as the gallop, all four feet leave the ground-but not when the legs are outstretched, as you might expect. In reality, the horse is airborne when its hind legs swing near the front legs, as shown in Muybridge's photos. A related gait, the canter, is similar to the gallop, except that two hooves land at the same time, so listeners hear three hoofbeats instead of four.
Flights Of Fancy
Before Muybridge's photos revealed the horse's true gaits, galloping horses were often portrayed flying through the air with all four legs outstretched--something that never actually happens.
When walking, the horse never gets all the way off the ground. This uses much less energy than the other gaits but limits how fast the horse can go.