Subject to variation according to the situation, one twentieth to one third of a command may be assumed as a suitable strength for the advance guard. The larger the force, the larger in proportion is the advance guard, for a large command takes relatively longer to prepare for action than a small one. In large commands it is usually composed of all arms, the proportions depending on the nature of the work, character of the country, etc. DISTANCE FROM THE MAIN BODY While the distance between these two bodies should be great enough to prevent needless interruptions in the march of the main body, and to give the latter time to deploy should the enemy be encountered, it should never be so great that timely support of the advance guard becomes impracticable. [Illustration: PLATE SHOWING the IDEAS INVOLVED IN an ADVANCE GUARD As you go from the point to the main body note that the distances are greater as the groups become larger. Larger groups require more time and space, when getting ready for action, than small groups. A very important thing to remember in connection with this plate is that you have only such groups in an advance guard as are necessary to insure protection for the main body.] DISTRIBUTION OF TROOPS An advance-guard order generally describes the following distribution of troops: Advance cavalry. Support. Reserve. The manner in which the advance-guard cavalry is employed depends upon the situation. Its proper place is in the direction of the enemy, and generally all or the greater part is used as advance cavalry. If weak in numbers, it may be assigned to the support. ADVANCE CAVALRY The advance cavalry is that part of the advance-guard cavalry preceding the support. It reconnoiters far enough to the front and flanks to guard the column against surprise by artillery fire, and to enable timely information to be sent to the advance-guard commander. SUPPORT Following the advance cavalry is the support, varying in strength from one fourth to one half of the advance guard. In mixed commands it consists of infantry, to which engineers may be attached. If there is no advance cavalry, some cavalry should be attached to the support for reconnoitering duty. As the support moves out it sends forward an advance party several hundred yards, the distance varying with the terrain and the size of the command. The advance party supplements the work of the advance cavalry, reconnoitering to the front and flanks to guard the support against surprise by effective rifle fire. The patrol preceding the advance party on the line of march is called the point, and is commanded by an officer or an experienced noncommissioned officer.