Although the choice of lines of advance and the combined action of the reconnoitring squadrons are often weighty factors of success, yet on the other hand, in order to obtain early and sufficient intelligence of the enemy, it is of the highest importance that the patrol system should be properly ordered according to the needs and probabilities of the situation. The "Field Service Manual" gives the necessary principles for their action. They must, it says, be sent forward along the roads that the enemy is most likely to use. By so doing, certain results must, under any circumstances, be obtained. On the other hand, it is a mistake to send forward single patrols against a wide front. Under such circumstances a patrol is always in doubt which way to go, will probably divide, and cannot, at all events, be everywhere. From such procedure, which is unfortunately only too common, reliable results cannot be expected, and it is never certain if observation is being carried out in any given direction. Such a faulty course of action usually originates from a certain confusion of thought on the part of the leader as to his own intentions and his suppositions as to the enemy. A clear appreciation of the situation ensures at the same time a clearly defined course of action. If, however, no sort of idea can be formed as to what the enemy is likely to do, the patrol system must be extended, not only in those directions from which the enemy may be expected, but in others where it is possible that he may be met with. Any turning movement on the part of the hostile forces must, in this manner, be continually guarded against. The number of patrols sent out will, of course, depend on the importance of the task. If the strength of a squadron is insufficient to provide them, it must be supplemented by patrols detailed from other squadrons. The relief of such patrols, also, may have to be carried out by the same means. Cutting down the number of distant patrols is to be avoided as far as possible. Economy of force can be better obtained by careful husbanding of strength in the close reconnaissance and service of security.