According as we quicken the pace at the work on "two tracks," in order to pass from the school walk to the ordinary trot, or even to the fast trot, it becomes more and more difficult to employ the " aids " in an appropriate manner. We should, in fact, hold the horse very straight in the hand, because every effort to straighten the hind quarters, or to support the forehand, diminishes the propulsion, which ought to be extremely energetic. To obtain a maximum of impulse at the quickest pace, we must keep the forehand and hind quarters absolutely on their own respective tracks, and must combine the energy of our legs, which give the impulse, with the delicacy of the constant action of the diagonal effects,^[1] which enable us to keep the horse in position, without diminishing the impulse in any way.

This movement is perhaps the most inconvenient one, on account of the extreme difficulty of correctly combining the effects of the " aids " with great propulsion. Not the least difficulty is to hold the horse always straight. The direction of the impulse, even in work on two tracks, will always pass between the two ears, if the head is well placed.

The correct position during work on two tracks at a fast trot, is very difficult to keep. In fact, the energy of the pace increases the natural disposition of the rider to carry his body to the side opposite to that to which he is going. Hence the necessity of continual watchfulness on his part.

The great difficulty as regards the horse, is to make him quicken the trot without breaking into the canter. This is the touchstone of impulse, and the proof that the animal answers freely to the " aids."

Work on two tracks, as I do it, in no way resembles the