As a father would interpose himself between his wife and children and an attacking bulldog, so would a military commander provide a similar protection for his camp. We see from this one of the big duties of an outpost commander, i.e., especial attention should be devoted to the direction from which the enemy (bulldog) is coming or is thought to be coming, and a probably less degree of attention to other points. Consider yourself a member of General Sherman's army during its march from the North on Atlanta. You are to camp for the night on a very open piece of ground. You do not know where the enemy is, but you believe that he is somewhere south of you. The troops are tired. They have had a long, hard march. Let us suppose it is your duty to provide the security of the main body for the night. General Sherman has given you a certain number of men for this purpose. Just how would you go about it? Regardless of other considerations, it is imperative that your own main force be not surprised or caught off guard by any contingency, however exceptional. To secure this immunity, it is necessary to send men or groups of men in the direction of the probable advance of the enemy, anti to arrange these men or groups of men so that they can be of assistance to each other. This we call forming an outpost. It may be possible to have a line of protection extending around the entire camp. It must be extended and arranged so as to keep the enemy so far away from our main body that he cannot observe our numbers or our position. The enemy must not be permitted to approach close enough to the main body to annoy or surprise it. Experience shows that all of this is best accomplished by placing: 1st, some groups or line of groups farthest from our main body and closest to the enemy in order to observe, to report the movements of the enemy, and, when necessary, to make a temporary resistance; 2d, a line of resistance ("supporting groups") called "supports" upon which the first line can retire before, being swamped by superior numbers; 3d, large groups, or line of groups ("line of reserves"), so located that they may go to the assistance of the second line in case of necessity. Such arrangements may be illustrated by the following diagram. [Illustration: PLATE SHOWING THE MAIN IDEAS INVOLVED IN SECURITY Danger zone Cavalry