The duties of the vanguard are: (1) To examine thoroughly the ground and remove all obstructions from the road. (2) To gain information of the enemy, especially when the cavalry division is not in advance. (3) To drive back or capture any detachments of the enemy they may find or hold the ground until can receive reinforcements. As the principal duty of the vanguard is reconnoiter ing, it should be largely composed of cavalry. The duty of the reserve is to fight and it would naturally be composed of infantry and artil lery.
The remainder of the unit from which the advance guard is taken ought, when convenient, to march at the head of the main body. The place for the commander of the advance guard is with the reserve. In open country the scouts and flanks should operate at considerable dis tances from the column and connecting files should be placed to insure rapid communica tion.
Cavalry must lead the vanguard and furnish scouts and flankers when the country permits. It can move with great rapidity, can examine places at a distance and quickly regain its place without delaying the march. It must push forward boldly and keep well in advance. It must furnish the regular patrols and detachments to examine lateral roads. The role of the cavalry is reconnais sance, but as it may meet with obstacles to its progress, such as detachments of the enemy's infantry, villages defiles and roads, it must be i accompanied by infantry to which these duties must be assigned. The cavalry may ride around a village or small wood and examine the outside, but it should not enter until they have been explored by the infantry. While the infantry is engaged in the examination, cavalry patrols should be sent on the roads beyond on the lookout for the enemy. De files, ravines and rough country generally must be examined by the infantry. As all kinds of country are apt to be found in a day's march, the advance party and flankers must not be cavalry alone. It is impossible to give a gen eral rule as to the proportions of the various arms.
The mobility and the offensive and defensive powers of modern field artillery have become so great that it is now assigned an important place in the advance guard in country favorable to its movements. As it must come into action early, some pieces are frequently attached to the support and the re mainder of the battery or batteries march with the reserve. A division would have one battery with the advance guard, two pieces to march at the rear of the support and the other pieces behind the first battalion of the reserve. The limber-chests should he filled with ammu nition and the caissons be left in the rear out of the way. It can assist in dislodging the enemy from villages, buildings, woods and bridgeheads.
The battles of the future will generally be preceded by a concentration similar to that of the German armies, at least for the corps of the first line. There is nothing to prevent placing the corps artillery in the advance guard if the situation is strong and well known. No inconvenience will result, for when this artil lery is called to participate in the it will take the trot and leave vacant the interval between the advance guard and the main body for the zone of manoeuvre. In immediate con
tact with the enemy the advance guard must form a curtain of exploration with its skir mishers and advanced parties while the main line of resistance must be formed from the reserve. The masses will march in the rear of the advance guard. The disposition will depend upon the ground and the Intentions of the chief the important thing is that the ar tillery find the ground free in its front. The artillery has also a reconnaissance role in con nection with the cavalry for, with its long range, it can assist in searching by its fire places unapproachable to the cavalry.
Infantry.—The role of resistance belongs to the infantry, as it is essentially the fighting arm in the combination. Its mobility imposes upon it also the duty of assisting the cavalry in reconnaissance work and of covering the artillery. The more artillery in the advance guard the more infantry it must have. In rough country the service of exploration and the advance guard duty will fall almost en tirely upon the infantry. In the combat with the enemy's advance guard the infantry must advance quickly to protect it from the enemy's infantry fire. We may say that all of the duties, which from the nature of their organization the cavalry and artillery cannot perform, fall to the lot of the infantry. Its role is "to con quer and to preserve." A light bridge train and some engineer troops should also be assigned to the advance guard to bridge streams, destroy obstacles and repair roads for the progress of the main body.
The Commander.--:When the enemy is near, the selection of a commander for the advance guard is very important. He must combine boldness, activity and knowledge with good judgment, and be so well disciplined as to subordinate his actions to carrying out the wishes and instructions of the commander-in chief, and avoid bringing on engagements through his own desire for distinction. He is responsible for the proper arrangement of the various parts, and that each faithfully performs its particular function. He must see that in formation obtained as to the strength, position or movements of the enemy is promptly and accurately transmitted to the commander-in chief. Before assuming command of the ad vance guard, he reports to his chief for instruc tions. If they are verbal, he should write them in his notebook and have them verified. He should quickly inspect his command, divide it into the proper parties and give his subordi nate chiefs their general instructions before the march is begun. If attacked, he must do one of three things, viz.: (I) Move forward and drive the enemy from his position. (2) Assume a defensive position and hold it until he can be reinforced from the main body. (3) Or, if outnumbered, retire slowly on the main body, using every device to check the progress of the enemy until the main body can be formed. See FLANK GUARDS, REAR GUARDS and VANGUARD.