(n) _March Outpost_.--A march outpost is usually an advance guard halted, with observers in each unit on the alert. A cossack post might be established on a good near by observation point. The march outpost is the protection furnished the main body at short halts, or on making camp before the outpost is established. (o) _Outpost_.--The outpost may be best illustrated by circles: Each support is numbered from right to left. Each outguard in each support is numbered from right to left. Each sentinel post in each outguard is numbered from right to left. Outguards are divided into three classes, cossack posts, sentry squads and packets. A cossack post consists of 4 men, 1 posted in observation near the posts of the remaining three. A sentry squad consists of one squad, posts a double sentinel post in observation near the post of the squad. A picket consists of two or more squads not exceeding half a company. It furnishes cossack posts, sentry squads, sentinel posts, and patrols. It is usually placed at the more important points of the outguard line, as a road fork, etc. The post furnished by pickets may be as far as 100 yards away. There should be also a sentinel post near the picket in observation. If the outguard consists of two or more companies there is a reserve. The reserve is held at some suitable point, where it can readily support the line. The reserve maintains connection with the main body and the support. The support occupies the line to be held. This line should be entrenched. The support maintains communication with its outguards and with each support on its flanks. It also sends out the necessary reconnoitering patrols. The outguards furnish sentinel posts and maintain communication with them, and with the outguards on each flank. It is the duty of the support commander to inspect his line and make such changes in the outguards as he deems necessary, then to report to the outpost commander with a sketch if practicable of his line when his dispositions are completed. The outpost commander should inspect the line, order such changes as he deems necessary, and report with a sketch of the outpost line to the commander of troops when his outpost has taken up its position. "The support commander must practice the greatest economy on men consistent with the requirements of practical security." Instead of using outguards along the whole front, part of it may be covered by patrols. [Illustration: Plate #12 DIAGRAM OF OUTPOST LINE] Outline of Field Service Regulations. LAND FORCES OF U.S. Regular Army. Organized Land Militia. Volunteer forces. How Grouped: Mobile Army. Coast Artillery. Mobile Army: For offensive operations against enemy and so requires maximum degree of mobility. Basis of organization the division, a self-contained unit composed of all necessary arms and services.