=Italy.= The distance between companies is 10 paces (7.5 m.). The battalion has a depth of 422 m. on the march. 8. THE REGIMENT AND THE BRIGADE. For a discussion of the importance of the regiment and of the brigade see page 37 _supra_. All movements must be executed in an orderly manner by regiment and brigade, in any formation, without breaking up tactical units, and the entity of the whole body must be preserved at the same time by a skillful use of the terrain. If necessary, a base battalion may be designated. When regiments or brigades are assembled, the formation, disposition, intervals and distances of the tactical units depend upon the terrain and the intentions of the commander. Frequently the tactical units (battalions and regiments) are assembled in separate groups. When considerations of the enemy and the terrain do not dictate otherwise, the battalions, each, as a rule, in deep column, are posted in one or more lines, at 30-pace intervals and distances, rear battalions covering those in front or the gaps between them. An appropriate formation will frequently be that in which route columns are placed abreast and on the same line. In the brigade, when assembled or deployed, the regiments may be placed abreast of each other, on the same line, or in rear of each other, _i.e._, in line or in echelon. When the regiments are formed side by side, two adjacent independent sections are created, each commanded by a regimental commander; this insures better supervision, better control, and a more energetic conduct of the action, since the first line can be reinforced by troops belonging to the same organization. This formation, moreover, facilitates tactical combinations. It may, however, be a disadvantage that the first line is not subject to the orders of a single commander; that it is difficult to employ the reserve battalions in one body; and that the brigade commander can influence the action only by withdrawing units from the regiments for the purpose of forming a reserve.[83] The echelon formation, each echelon consisting of a regiment, is frequently used in rencontres, because troops are thrown into action directly from route column. The regimental commanders then become leaders of echelons, the first line cannot be reinforced by its own troops, and the organizations of different regiments finally become mixed. The echelon formation is proper only when the second line is intended to be used independently abreast of the first in the course of the action; for example, on a flank, for the purpose of making or warding off a flank attack.[84] When part of a larger force, the most suitable combat formation for troops is usually the one in which the regiments are formed side by side.