Page:Equitation.djvu/253

 therefore, a horse is in equilibrium, the shifting of the rider's weight from his left haunch to his right will turn the horse and send him forward to the right. Are we, then, outside the natural laws of motion? No. We are obeying the law which teaches that a body in motion will continue to move along the same straight line until another force interferes. This other force is the rider's weight, which, when applied at one side of the center of gravity, displaces this and forces the horse to turn in that direction.

All this is undeniable. It is easy, therefore, to understand the fights of these two masters with the horses educated by them. The horses walked and trotted in diagonal. The riders employed the lateral effects. The horses galloped in lateral. The riders, to train them to that gait, used a half-diagonal effect. Naturally, the horses became confused between their instinctive gaits and the riders' effects which were flatly contrary to them.

However, if a horse is not in a state of equilibrium, this change of weight will have no effect, and the scientific equitation is not concerned with the matter.

double is a figure of manege in which the rider crosses the quadrangle from side to side and returns to the original piste at the same hand. It involves, therefore, merely two changes of direction to one side or the other.