The strength of distant patrols should never be arbitrarily laid down, as in this respect also the circumstances must be taken into account. Patrols which are far distant from the road upon which the squadron is advancing, and which can only be reached with difficulty, require a greater degree of independence than those in the immediate neighbourhood, which can be rapidly supported or strengthened. The probability, also, of meeting with superior hostile force demands a greater proportion of strength. Under certain circumstances a whole troop may be used as an independent patrol. At the same time a wise economy of force must be practised so that the fighting and marching efficiency of the squadron does not suffer too much. To this end, quite weak patrols must be made to suffice in directions of secondary importance. A second in command must be detailed to every patrol. There should also be a supply of trained lance-corporals ready to lead such patrols as may be required to carry information to the rear. The strength of patrols will depend largely on the number of messages that they are expected to send in. As a general rule, in large operations, not more than two messages will be required from each patrol during the day. It is only when the opposing armies approach each other, and the distant patrols gradually become close patrols, that it will be necessary to report frequently on tactical events. The distances, however, will then have so far diminished, that a reinforcement of the patrols from the squadrons would probably be possible if they have become over-weak through transmission duties. Like the reconnoitring squadrons, the patrols require relief from time to time, as the same patrol leader cannot be expected to remain in continuous touch with the enemy. The strength of patrols, therefore, will generally have to be calculated according to the number of messages and the number of days during which the same men are required to be in contact with the enemy. It is only when a special fighting strength appears necessary that these numbers should be exceeded. On the other hand, the patrols in friendly country may be made weaker than when in the enemy's territory, as, in the latter case, it will scarcely be possible to send in messages by single orderlies. Careful preparation must be made for the relief of patrols. Every patrol that is sent out must know when, and approximately where, it can rejoin the squadron. The relieving patrol should arrive on the field of exploration before the original patrol returns. The two patrol leaders should meet where possible. All the patrols should never be relieved at one time, as such a procedure would tend to weaken the squadron too much.