Several factors unite to explain this circumstance. In the first place, only the shortest moment of time is available for consideration, and then this rapid consideration and decision have to be given under the most unfavourable external conditions, at the fullest speed of one's horse, or in the maddening confusion of the melee. Further, in most, cases it will be quite impossible for the Leader of a Cavalry 'Mass' to take in with accuracy the strength and dispositions of the enemy. The more extended radius of action of modern firearms and the greater distance between the contending forces thereby conditioned must in the future render this much more difficult than in the past. Very rarely will it be possible for the Leader either to alter or cancel an order once given in consequence of information subsequently received. Even of the ground itself, the importance of which is so much greater for the Cavalry than for any other Arm, it will be impossible for the Leader to form for himself any actual picture. Either it is already in possession of the enemy and of his patrols, or at least in their sphere of action, or it cannot be readily grasped from a single standpoint, and the rapidity of movement allows no time to reconnoitre it sufficiently. Constant reference to maps, even when available, is impossible, and the best of these do not reveal exhaustively the actual nature of the ground to be traversed. The orders must therefore be based on a general consideration of the circumstances, for the Leader cannot gauge with even approximate accuracy the strength of his enemy from the resistance he encounters, like his more fortunate comrade of the Infantry. His only remaining means of influencing the course of the action lie in his intact reserves. For subordinates, indeed, the case is even worse, for they will rarely find existing conditions in accordance with the conception on which their orders were issued, and will seldom have time to refer to Headquarters for further instructions. It must, therefore, be apparent that only the most exceptional Cavalry training, combined with high executive talent, can suffice to compensate for all these difficulties. Really successful leading will only be assured to the Cavalry General when the machinery he sets in motion is technically finished down to the last detail. In the first place, the least that can be demanded is that the observation of the enemy and distribution of orders are so organized that the system works with absolute certainty. On the former depends the correct choice of the moment of attack; on the latter that the troops are employed in the required direction.