DISTRIBUTION OF TROOPS
The proximity and conduct of the enemy control, to a large extent, the formation of a rear guard. When it is not necessary to withdraw in deployed lines, the greater part of the rear guard marches on the road in column of route, taking up a formation resembling that of an advanced guard faced to the rear. The distribution of troops is therefore similar to that of an advance guard, namely:
Reserve.
Support.
Rear cavalry.
The rear cavalry is that portion of the rear-guard cavalry following the support. The support, as in an advance guard, is divided into two parts; that part nearest the enemy is called the rear party and marches with a rear point.
DISTANCES
The distance of the rear guard from the main body and between the fractions of the rear guard are about the same as in the case of an advance guard. If marching at night, the rear guard draws nearer the main body.
REAR GUARD OF AN ADVANCING FORCE
If there is a possibility that the rear of the column may be attacked, a rear guard of suitable strength and composition is provided, its conduct is practically the same as that of the rear guard of a retreating force.
It generally marches in rear of the trains, those organizations following the combatant troops without distance.
OUTPOSTS
The size and disposition of the outpost will depend upon many circ.u.mstances, such as the size of the whole command, the proximity of the enemy and the situation with respect to him, the nature of the terrain, etc.
A suitable strength may vary from a very small fraction to one third of the whole force. For a single company in bivouac a few sentinels and patrols will suffice; for a large command a more elaborate outpost system must be provided. It should be no stronger than is consistent with reasonable security.
The most economical protection is furnished by keeping close contact with the enemy by means of outpost patrols, in conjunction with resisting detachments on the avenues of approach.
The outpost should be composed of complete organizations.
The positions held by the subdivisions of the outpost should generally be prepared for defense, but conditions may render this unnecessary.
Troops on outpost keep concealed as much as is consistent with the proper performance of their duties; especially do they avoid appearing on the sky line.
COMPOSITION
A mixed outpost is composed princ.i.p.ally of infantry. The infantry is charged with the duty of local observation, especially at night and with resisting the enemy long enough for the main body to prepare for action.
The cavalry is charged with the duty of reconnaissance, and is very useful in open country during the day. If the infantry has been severely taxed by marching or fighting, a large part of the outpost may be temporarily formed of cavalry.
Artillery is useful to outposts when its fire can sweep defiles or large open s.p.a.ces and when it commands positions that might be occupied by hostile artillery. The guns are carefully concealed or protected and are usually withdrawn at night.
Machine guns are useful to command approaches and check sudden advances of the enemy.
The field trains of troops on outpost duty generally join their organizations; if an engagement is probable, they may be held in rear.
DISTRIBUTION OF OUTPOST TROOPS
The outpost will generally be divided into four parts. These, in order from the main body, are the reserve, the line of supports, the line of outguards, and the advance cavalry.
[Ill.u.s.tration: PLATE SHOWING THE IDEAS INVOLVED IN AN OUTPOST]
The distance separating these parts, and their distance from the main body, will depend upon the object sought, the nature of the terrain, and the size of the command. There can be no uniformity in the distance between supports and reserve, nor between outguards and supports, even in the same outpost. The avenues of approach and the important features of the terrain will largely control their exact positions.
The outpost of a small force should ordinarily hold the enemy beyond effective rifle range of the main body until the latter can deploy. For the same purpose the outpost of a large force should hold the enemy beyond the artillery range.
The reserve const.i.tutes the main body of the outpost and is held at some central point from which it can readily support the troops in front or hold a rallying position on which they may retire. The reserve may be omitted when the outpost consists of less than two companies.
The reserve may comprise one-fourth to two-thirds of the strength of the outpost.
The supports const.i.tute a line of resisting and supporting detachments, varying in size from a half company to a battalion. They furnish the line of outguards.
The supports are numbered consecutively from right to left. They are placed at the more important points on the outpost line, usually in the line on which resistance is to be made in case of attack.
As a general rule, roads exercise the greatest influence on the location of supports, and a support will generally be placed on or near a road.
The section which it is to cover should be clearly defined by means of tangible lines on the ground and should be such that the support is centrally located therein.
The outguards const.i.tute the line of small detachments farthest to the front and nearest to the enemy. For convenience they are cla.s.sified as pickets, sentry squads, and cossack posts. They are numbered consecutively from right to left in each support.
A picket is a group consisting of two or more squads, ordinarily not exceeding half a company, posted in the line of outguards to cover a given sector. It furnishes patrols and one or more sentinels, double sentinels, sentry squads, or cossack posts for observation.
Pickets are placed at the more important points in the line of outguards, such as road forks. The strength of each depends upon the number of small groups required to observe properly its sector.
A sentry squad is a squad posted in observation at an indicated point.
It posts a double sentinel in observation, the remaining men resting near by and furnishing the reliefs of sentinels. In some cases it may be required to furnish a patrol.
A cossack post consists of four men. It is an observation group similar to a sentry squad, but employs a single sentinel.
At night it will sometimes be advisable to place some of the outguards or their sentinels in a position different from that which they occupy in the day time. In such case the ground should be carefully studied before dark and the change made at dusk. However, a change in the position of the outguard will be exceptional.
Sentinels are generally used singly in daytime, but at night double sentinels will be required in most cases. Sentinels furnished by cossack posts or sentry squads are kept near their group. Those furnished by pickets may be as far as 100 yards away.
Every sentinel should be able to communicate readily with the body to which he belongs.
Sentinel posts are numbered consecutively from right to left in each outguard. Sentry squads and cossack posts furnished by pickets are counted as sentinel posts.