REPORT OF CAPT. GEORGE B. M'CLELLAN. 305 



directions. In an open, level country, the cavalry marches at the head ; in a broken country, 

 there is only a small detachment of cavalry at the head, to furnish advanced detachments and 

 patrols. An advanced detachment of cavalry, which sends out patrols in front and on its 

 flanks, moves at the distance of a few miles in front of the advanced guard. Small detachments 

 of cavalry move in a line with it on the other roads ; also others on the flanks of the main 

 advanced guard, to secure it against being turned. All the front and flank detachments main- 

 tain a constant mutual communication by means of patrols, and thus keep in sight the whole 

 space in front of the main body over a great extent. But if the flank columns of the main body 

 march at a great distance from the main road followed by the advanced guard, then, in addition 

 to this last, each flank column detaches a small advanced guard for its own security. 



§ 159. If the advanced guard is composed of different arms, its distance from the main body 

 depends not only upon its strength, but also on the following circumstances : 1. On its compo- 

 sition. Cavalry may advance much further than infantry. 2. Upon the locality. The more 

 fully the nature of the country secures the advanced guard against being turned, the further 

 may it move from the main body. 3. Upon the object in view. Prior to defensive combats in 

 position, it is advantageous to have the advanced guard as far from the main body as possible, 

 in order to secure time for making the necessary arrangements ; but if the main body is already 

 concentrated for a decisive attack upon the enemy, it is sometimes well to be entirely without 

 an advanced guard ; during a pursuit, the main body should follow the advanced guard as 

 closely as possible. 4. Upon the order of march of the main body. The longer the time 

 needed by the main body to form in order of battle, on account of the intei^vals between the 

 columns, the nature of the ground between them, the length of the columns, &c., so much 

 further forward should the advanced guard be pushed. In general, the distance of the 

 advanced guai'd from the head of the main body should be a little greater than the interval 

 between the outside columns of the main body. 



§ 160. Plate No. 4 gives an example of the arrangement of an advanced guard composed of 

 one brigade of light cavalry, 8 battalions of infantry, one battalion of sappers, 6 pieces of horse 

 artillery, and 12 pieces of foot artillery ; the main body following in 3 columns. Disregarding 

 minute details, this is established as the basis of the arrangement of an advanced guard, without 

 regard to the ground. 



Whatever slight changes may be made necessary by the nature of the country, can easily be 

 made with the aid of a map and the special information obtained in other ways. 



§ 161. If the country is partially broken and obstructed, it is advantageous to have four or five 

 companies of infantry just behind the leading detachment of cavalry to examine places that are 

 difficult or dangerous for the latter. 



§ 162. Upon the plains the patrols are of cavalry ; in a mountainous region, of infantry. In 

 the latter case, not only the advanced detachments and patrols are of infantry, but also the head 

 and rear of every column ; the cavalry and artillery march in the middle, under the protection 

 of the infantry. 



§ 163. In passing through a village, the infantry enter it first, if there are any with the 

 advanced guard ; the cavalry either ride rapidly around it, or, according to circumstances, halt 

 a little before reaching the village, and wait until the infantry have passed through. 



§ 164. The passage of important bridges, ravines, and defiles, should be effected in the same 

 manner, the infantry examining them. As soon as the infantry have crossed and formed on the 



39 © 



