=207.= Manner of applying the aids: The action of the reins and legs and weight should not be continuous. The trooper alternately closes and relaxes the fingers, the hands preserving contact in the intervals between the actions. In the same manner he uses the legs, neither gripping nor releasing altogether, but preserving light contact in the intervals between the blows with the calves. The weight likewise is used in a similar manner, being quickly applied to the front, to the rear, or to a side, alternating with returns to the normal position. If an action of the aids is prolonged the horse has opportunity to establish the corresponding resistance, but if produced by =repeated applications= the effect is very marked. All action of the aids should diminish in intensity when obedience begins and cease entirely as soon as the desired result is secured. Troopers must be thoroughly trained in riding with the reins in one hand. =208.= The instructor, in teaching troopers to avail themselves of their legs and reins, is governed by the preceding considerations, and from the first watches vigilantly the action of the aids. The hand should always be kept low. The most thoughtful care should be exercised in the combined application of the aids, so that they may not be opposed to each other in their action; that is, one favoring the intended movement, the other opposing it. The instructor impresses upon the troopers that their hands must be kept still; that is, free from bobbing up and down, and pulling, and from giving and taking when there is no reason therefor. Likewise their legs should remain in light contact with the horse's sides and the heels not be used to kick the horse constantly in a nervous manner. Moreover, that the effects of the aids may be perfectly clear, and that there may be no contradiction between them, =there should never be simultaneous action of the direct reins demanding slowing up or halting and of the legs provoking a forward movement=. This condition is essential for preserving the composure indispensable to the horses of the troop. =242.= =Posting=: Posting is habitually employed when the troopers have stirrups and understand their use. It is executed as follows: The horse moving at a trot, the trooper inclines the upper part of his body forward, then supporting himself on the stirrups while maintaining the clinging of his knees he rises under the impulsion of the horse, maintains his position detached from the saddle while the succeeding impulse is produced, again sits down in the saddle, and continues in this way, avoiding alternate impulses. At the beginning the mechanism of posting is made easier to the trooper by causing him to stroke the horse's neck or to grasp a lock of the mane with either hand, thus determining the forward inclination of the body.