since otherwise the hind legs could not be brought into the perpendicular relation to the spine.
So long as the horse remains at rest with his four limbs perpendicular, the state of equilibrium can be demonstrated. But with the horse in action, only the eye of the spectator or the equestrian tact of the rider, through his seat, can detect it. The spectator can see the four legs leave the ground and return, two by two, diagonally at walk, trot, and movement backward.
The rider, under these conditions, feels in his seat the squareness and equality both of the different strides and of each step. The horse gives a light and agreeable contact upon the hand, the head and neck are perfectly steady and yet firm, while the rider feels that, with the least tension on the reins, the neck will flex like an elastic band. All the time he feels in his seat that, with the least shifting of his weight or the slightest alteration in legs, hand, body, or head, the equilibrium will vanish. The animal moves between the rider and the ground, rhythmically. Every joint is supple, and every part of the mechanism does its task with power, freedom, and in perfect synchrony. Fillis, the grand master, is right when he says, "The rider feels as if the horse were flying." But Baucher, the great dead, is also right when he says, "The sea is calm, but full of rocks!"
Unhappily, this state of equilibrium tends always to be disturbed in consequence of the various
