Good communication between the several portions is in all such cases an important factor. If necessary it must be effected by the help of the guns. Generally speaking, it will facilitate and prepare communication if the separately advancing columns are kept informed as to the rate of march, so that each column can at any moment calculate where the others will be in a given time if nothing unforeseen occurs. This also enables information to be sent by the shortest route to points which can to a certain extent be previously determined. The arrangements for the advance form at the same time the foundation for the action of the actual reconnoitring organs and the complete establishment of the reconnaissance system. Directions for this will be found in the "Field Service Manual." It is laid down that reconnoitring squadrons will be pushed forward from the various groups of the army cavalry, and will be allotted zones of reconnaissance in the direction of the enemy. The reconnaissance itself will be carried out by patrols. The breadth of these zones must continually alter according to circumstances. If it be necessary to reconnoitre on a broad front with a comparatively weak cavalry, very wide zones will often be necessary. On the other hand, the closer the system of reconnoitring squadrons can be established, the more reliable the manner in which reconnaissance will be carried out, and the easier will it be to hamper the enemy's efforts at gaining intelligence. If the "Field Service Manual" lays down a certain breadth as normal, this naturally only indicates that, under ordinary circumstances, squadrons on a wider front would no longer be in a position to carry out their duties to the full; nothing more. The frontages laid down should never lead either to the perceptible weakening of the fighting value of a force by sending forward too many reconnoitring bodies, or, on the other hand, to the inability of the reconnoitring organs to cover the space demanded by the strategical situation. A well-considered allotment of areas is therefore of special importance, and a matter for the higher leader to decide. For the arrangements for reconnaissance inside the zone apportioned to him, the squadron leader is, on the other hand, correspondingly responsible. It is at the same time laid down that no squadron should interfere in a neighbouring zone. Although in these measures the principles for the reconnaissance may be sought, it must be clearly understood _that the original allotment of zones cannot always hold good_. This arrangement is only practicable and suitable so long as the opposing armies are frontally approaching each other. As soon as the directions of march form an angle with each other the conditions alter.