Chapter II

Mahan’s Outpost


123. Position and Formation. On the field of battle, whether the object be to attack, or defend, the infantry is divided into three bodies; an advanced-guard, the main-body, and a reserve. Their proportion will depend upon the total force, and the character of the position occupied. The advanced-guard must be of sufficient strength to hold the enemy in check, but, at the same time, the main body, upon which the brunt of the action should fall, must not be left of insufficient force, by unnecessarily increasing the advanced-guard; and the reserve should be strong enough to repair any disaster that may befall the main-body; or to profit by its success in accomplishing the complete overthrow of the enemy-

124. These three bodies are separated from each other by intervals which will depend upon the nature of the ground. The advanced-guard occupying the front; the main-body at a distance from 150 to 300 paces in its rear; and the reserve at a like interval to the rear of the main body. Where the ground, for example, is undulating, and therefore favorable to masking the troops from the enemy’s fire, these intervals may, if requisite, be reduced to 80 or 100 paces.

125. The troops composing these three bodies will be formed either in columns of battalions, or be deployed, according to the circumstances under which they may be placed. For an attack, for evolution, or for defense against cavalry, the formations of columns of battalions is best. To repel the enemy’s attack by a fire, and in some cases, to present a less favorable mark to his artillery, the battalions are deployed. The battalions, whether deployed or in column, preserve the proper intervals for evolutions; these intervals may be increased in obstructed ground without weakening the defense.

126. The battalions composing the main-body may be drawn up in one or two mines. The latter usually obtains only when a large force is present. In this case the re serve no longer holds the position of a third line, as in the other; but forms an independent body, to be used according to the emergency; the second line supporting the battalions of the first, and, for this purpose, occupying positions to the rear, opposite to their intervals.

127. Defense. When the position is taken up to receive the enemy’s attack, and then either to remain on the defensive, or to assume the offensive, as circumstances may justify, the advanced-guard will be posted on the ground most favorable to hold the enemy in check, and so force him, by disputing it with tenacity, to develop his means and plans. This is best done by a judicious combat or skirmishers, who, for this purpose, are thrown forward 300 or 400 paces, to feel the enemy, and are only reinforced when closely pressed.

128. Whether the advanced-guard shall maintain its ground obstinately until reinforced by the main-body, or whether it shall fall back, either on the flanks or to the rear of the main-body, must be determined by the strength of its position. If this be so strong that the enemy’s loss in carrying it must be great, then it should be pertinaciously maintained; in the contrary case it must, after a suitable show of resistance, be abandoned.

129. As a general rule, troops should be placed as much out of view as practicable before they into action, by taking advantage of covers offered by the ground. The main-body should be kept masked in this way until it is called to engage the enemy. If it advance to support the advanced-guard, it will usually attack with the bayonet – if the advanced-guard is called in, the main-body will usually receive the enemy by its fire; the battalions being deployed for this purpose. If the enemy is staggered by this fire, or, in advancing, shows, by the wavering or confusion of his line, a want of confidence, the fire may be followed up either by a charge of the troops in line; or they may be formed in columns of attack before charging, if the enemy perseveres in his onward movement. A charge by a column, when the enemy is within 50 paces, will prove effective, if resolutely made.

130. The reserve is composed of the most reliable troops. It should be distinguished for cool courage; acting under all circumstances, either defensive or offensive, with circumspection and determined resolution. As the object of the reserve is to infuse greater energy into the action of the main-body, and, if necessary, to strike a last and decisive blow, it should be kept masked from the enemy’s fire and view until called into action. The proper moment for engaging the reserve is either when the enemy has been shaken in his attack by the resistance offered by the main-body, or when the latter is unable farther to resist the enemy’s efforts. If engaged too soon, the resistance offered to the reserve may prevent its making a decisive blow; if not engaged in time, the main-body may be too far exhausted and disorganized to rally.

In cases where the reserve forms a second line, to support the main-body, it should approach the first line when it becomes engaged, to be ready to replace it when circumstances may render it necessary. The advanced-guard, in such cases, should retire to the rear, to act as a reserve.

131. Attack. In the attack of infantry, the same fundamental dispositions are made as for the defensive. The advanced-guard will not throw forward its skirmishers until they are near enough to engage the enemy. The line of skirmishers should be strongly supported, and will press the enemy with vigor and without relaxation. If the force engaged be small, the main-body will regulate its movements by those of the line of skirmishers; if considerable, the reverse will obtain.

132. The main-body and reserve follow in column the advanced-guard, preserving the requisite intervals. The columns should take every advantage of the ground to mask their movements; getting rapidly over any where they are much exposed to fire. So soon as the advanced-guard is checked, it will fall back either on the flanks of the columns, or to the rear; and the main-body will be immediately brought into action, either by deploying and opening its fire, or by a vigorous charge with the bayonet. If the main-body falters in its attack or gives any signs of want of resolution, the reserve should advance at once through the intervals, and make a vigorous charge with the bayonet.

133. If the attack by the main-body is made with the bayonet, the interval between it and the columns of the reserve may be lessened to 80 or 100 paces. The flanks of the columns of attack, and intervals between them, should be occupied by skirmishers. This is an important precaution; as, by forcing the enemy to deliver his fire before the columns have reached within a destructive range, the main obstacle to their onward movement will be removed.

134. Pursuit. If the assailed retires, the pursuit must be conducted with system and in good order. The line nearest the enemy will throw forward a few troops in pursuit; which, in most cases, will be preceded by skirmishers. The line in close order, will follow these troops until it attains a good position to receive the enemy, should he make- an offensive movement, when it will be halted and formed in readiness for action. A pursuit by infantry alone cannot be pushed far, even should the enemy retire without any order, or show of resistance, as the retreating force will soon distance their pursuers.

135. Retreat. When, either in the defensive, or offensive, it becomes necessary to retire, the first point to be attended to is to withdraw the troops engaged; either to a good position to their rear, where they can halt and face the enemy, or else behind the line in their rear, which should hold the assailants in check, and allow the retreating troops to fall back in good order. Having fairly-got disengaged, dispositions must be promptly made to withdraw from the field. This may be done by the entire force moving off together, if the enemy shows no disposition to follow up his success with energy; or, in the contrary case, by retiring by successive portions; the line which withdraws falling some 150 paces to the rear of the one by which it is covered, whilst falling back, and then forming, to cover in turn the retreat of the latter. The dispositions made in the retreat will depend entirely upon the character of the enemy’s pursuit, and the features of the ground. It will usually be made in columns, covered by skirmishers, if the pursuit is made by infantry alone; if by cavalry, the retreat must be made with great circumspection; the troops retiring slowly and in good older, adopting the formation against cavalry; never hastening the march, unless very near a good position for defense, which should be attained as rapidly as possible, unless closely pressed by the cavalry.

136. If it be necessary to continue the retreat for some marches, under the eye of the enemy, a rear-guard must be formed; selecting, from a fourth to a third of the entire force, for this service. The main duty of the rear-guard is to hinder the enemy from pressing too closely on the main-body; and it should therefore, under no circumstances, allow itself to be forced back upon the main-body. The dispositions adopted by the rear-guard will depend upon the features of the ground; its rear will usually be covered by a line of skirmishers. The rearguard will keep within good supporting distance of the main-body; and, when pressed by the enemy, the latter, whenever a favorable position offers, will halt and form; to cover the former, and force the enemy to greater circumspection.

137.Measures for protracting an Engagement. In the attack, as in the defense, it may frequently become an object to protract an engagement, without coming to any decisive result; either for the purpose of holding a position for a certain time, to favor other objects, as the arrival of reinforcements; or to occupy an adversary upon one point whilst a decisive blow is preparing on another. This game can be played only upon ground favorable to alternations from the defensive to the offensive; and should only be intrusted to troops thoroughly conversant with the duties of skirmishers. The main-body is kept some two thousand paces to tile rear of the skirmishers in such affairs; taking advantage of the ground, and making suitable dispositions of the troops to avoid the effects of the enemy’s artillery. Small columns are thrown forward between itself and the troops engaged, which take post in covered ground, to be at hand to support skirmishers. – The troops engaged should be promptly reinforced, when the enemy presses onward; and attempts should be made, by charging him in flank, to force him to retire. The troops in action should be frequently relieved, and the opportunity should be seized, when the fresh troops come to make an onward movement on the enemy, and force him from any points he may have gained.

138. Defense against Cavalry. When infantry is threatened by cavalry, the proper formation to repel its charge is that of squares. If but one square is formed, it must rely on its own resources to beat off the enemy; but when there are several they may give mutual support by bringing a flank fire from one upon a force advancing on either of the twp contiguous to it. The safety of infantry against cavalry will depend upon the preservation of perfect coolness, good order, and connection in the ranks; the avoidance of any precipitate movements which bring about a surprise; and the husbanding of its ammunition, and reservation of its fire until the enemy is within a deadly range. Well disciplined infantry, whilst in position, and when not exposed to a fire of artillery, may securely trust to its own resources to repulse the best cavalry, so long as it adopts the proper precautions. If annoyed, as sometimes may happen, by the fire of a few horsemen, advanced to draw the fire of the squares, it will be better to throw out some skirmishers, ten or twelve paces from the squares, to keep off such attacks, than to open a fire from the squares.

139. Defense, & etc, against Artillery. Infantry may take advantage, either of covers presented by the ground, or occasionally shifting its position, to avoid the fire of artillery. Very slight undulations, or obstructions, like the low banks along the borders of ditches, will serve to cover troops, by causing the shot to rise above them. If no covers are at hand, the chances of casualties, when within point-blank range may be diminished by moving forward, or backward, some 50 paces; if the fire be a ricochet, the position should be -shifted some 50 paces to the right or left. The enemy’s batteries may be annoyed, and sometimes be forced to change their position, by sending out good marksmen, who advance singly to within some 250 paces of them; where, lying down, they can pick off the officers, men and horses.

140. Attack of Artillery. Whenever it is found necessary to carry a battery by the bayonet, the troops for this duty are divided into two detachments; one of which is charged with capturing the guns, and the other with attacking the supports of the battery. The dispositions made by the detachment which moves against the guns will be the usual one of skirmishers; the line surrounding the battery, and opening their fire upon it when within about 250 paces, taking advantage for this purpose of any covers, to screen the men. The supports of the line of skirmishers should be kept well to the rear to be ready against a flank movement on the line. If this maneuver succeeds in drawing the fire of the guns, and any confusion is observed among the men, then a rush must be immediately made upon them with the bayonet. The detachment against the supports of the battery will make its dispositions according to the kind of troops which compose the supports. If of infantry, the detachment to seize the guns, divided into two portions, will advance either in line, or column, as may be best, on the flanks of the line of skirmishers; gradually getting in advance of it, and closing on the flanks of the battery, so as to attack the supports in flank; keep to the rear of the line of skirmishers, in order to tempt the supports to move forward, and thus mask the fire of their guns. If the supports are of cavalry, the detachment, divided into two columns, will follow the line of skirmishers, in rear of the flanks; to cover it against a charge of the cavalry.


141. Position. This arm is usually placed in the rear of the infantry, on ground favorable to its maneuvers, and where it will be masked from fire until the moment arrives to bring it into action; here, if acting on the defensive, the cavalry watches its opportunity to support the other troops, driving back the enemy, by prompt and vigorous charges, when these are hard pressed; or, if on the offensive, biding its time, to rush upon the assailant, and complete his destruction; when his ranks commence to waver or show signs of disorganization from the assaults of the other arms

142. Formation. The habitual formation of cavalry for the attack is in a line of two ranks, with reserve, or support to its rear. The supports are indispensably requisite to guard against those chances of danger to which cavalry is particularly exposed, if attacked in turn, when in a state of partial disorganization after a successful charge; or when threatened by an offensive movement against its flanks.

The supports offer a safeguard against either of these dangers; for, if the front line is brought up by the enemy, after a successful charge, it can retire and rally in the rear of the supports; and if the enemy makes a movement against the flanks, the supports, placed behind them and in column, can form and anticipate the enemy’s charge. For the foregoing reasons, cavalry should not give way to a headlong pursuit after a successful charge, unless its supports are at hand; and, in cases where a charge is made without supports, a portion only should engage in pursuit, the rest being rallied to form a support.

143. Cavalry is seldom called on to use firearms. When on out-post service, or acting on the defensive on ground unfavorable to charging, a portion of the force may be dispersed as flankers, to hold the enemy in check by their fire. In this case their movements are regulated in the same way as other skirmishers.

144. Defense. The defensive qualities of cavalry lie in the offensive. A body of cavalry which waits to receive a charge of cavalry, or is exposed to a fire of infantry, or artillery, must either retire, or be destroyed: This essential quality of cavalry renders its services invaluable in retreats where the enemy pursues with vigor. In such cases it should be held in constant readiness to take advantage of every spot favorable to its action; and, by short and energetic charges, force the enemy to move with circumspection.

145. Attack against Infantry. So long as infantry maintains its position firmly particularly if the ground is at all unfavorable to the movements of cavalry, the chances are against a successful attack by the latter. Cavalry should therefore either wait patiently until a way is prepared for its action, by a fire of artillery on the enemy’s infantry; or until the infantry his become crippled and exhausted by being kept in action for some time; or else, watching its opportunity, make a charge whilst the infantry is in motion, so as to surprise it before it can form to receive the attack. Cavalry should direct its charge on that point of the enemy’s infantry where it will itself be exposed to the least column of fire. If the infantry is in line, the charge should be made on one of its flanks; if in square, on one of the angles of the square; and when several squares are formed, so as to afford mutual support by their fire, selecting the squares on the flanks as most vulnerable, from their position.

146. The formation usually recommended for charging against squares, is that of three squadrons in line at double distance, the leading squadron being followed by the others, either directly in its rear; or else the squadrons may be formed in echelon, successively overlapping each other by about the front of a platoon. The angle of the square is charged by each squadron in succession, if the charge of the one preceding it fails; the repulsed squadrons of each wheeling to the right, or left on retiring; to leave the way clear for its successor. A fourth squadron follows those in line; to surround the square and make prisoners if it should be broken by the charge.

147. To draw the fire of the infantry before charging, a few skilful flankers may be thrown forward, to open a fire on the square. Stratagem may also be tried, by moving along the front of-the infantry, at some 400 paces, and then charging, if is tempted to throw away its fire at this distance. In an attack where several squares are in line, if one fires to second another it should be instantly charged.

148. Attack against Artillery. In attacks against artillery, the detachment of cavalry should be divided into three bodies; one-fourth of the detachment being charged with carrying the guns; one-half to attack the supports of the battery; and the remaining fourth acting as a reserve, to cover the parties in advance, from an offensive movement’ against their flanks, or rear. The party to secure the guns make their attack in dispersed order, and endeavor to gain the flanks if the battery. When the battery has a fair sweep over the ground along which they must advance, attacks, they should, by maneuvering and false attacks, try to confuse the artillerists, and draw their fire before their charge. The attack against the support of the battery will be directed in the usual manner; the party maneuvring to gain their flanks.


149. Position. The manner of placing artillery and its employment must be regulated by its relative importance under given circumstances, with respect to the action of the other arms. In the defensive, the principal part Is usually assigned to the artillery ; and the positions taken up by the other arms will, therefore, be subordinate to those of this arm. In offensive movements the reverse generally obtains.

150. Defense. In defensive positions the security of the batteries is of the last importance. Unless the batteries are on points which are inaccessible to the enemy’s cavalry and infantry, they must be placed under the protection of the other troops, and be outflanked by them. As in the defensive, we should be prepared to receive the enemy on every point; the batteries must be distributed along the entire front of the position occupied, and on those points from which they can obtain a good sweep over the, avenues of approach to it: the guns being masked, when the ground favors, from the enemy’s view, until the proper moment arrives for opening their fire.

151. The distance between the batteries should not be much over 600 paces; so that by their fire they may cover well the ground intervening between them, and afford mutual support; the light guns being placed on the more salient points of the front, from their shorter range and greater facility of maneuvering; the heavier guns on the more retired points. Guns of various calibre should not be placed in the same battery. A sufficient interval should also be left between batteries of different calibre, to prevent the enemy from judging, by the variation, in the effect of the shot, of the weight of metal of the batteries. Those positions for batteries should be avoided from which the shot must pass over other troops, to attain the enemy. And those should be sought for from which a fire can be maintained until the enemy has approached even within good musket range of them. Where the wings of a position are weak, batteries of the heaviest calibre should be placed to secure them.

152. A sufficient number of pieces- selecting for the object in view horse-artillery in preference to any other- should be held in reserve for a moment of need; to be thrown upon any point where the enemy’s progress threatens danger; or to be used in covering the retreat.

153. The collection of a large number of pieces in a single battery, is a dangerous arrangement; particularly at the outset of an engagement. The exposure of so many guns together might present a strong inducement to the enemy to make an effort to carry the battery; a feat the more likely to succeed, as it is difficult either to withdraw the guns, or change their position promptly, after their fire is opened; and one which, if successful, might entail a fatal disaster on the assailed, from the loss of so many pieces at once.

154. In all defensive dispositions the ammunition should be most carefully husbanded. A fire should never be opened until the enemy is within good range; and, when once opened, be continued with perseverance and coolness up to the last moment in which it can be made effective.

155. Attack. In the outset of offensive movements, good positions should be selected for the heaviest pieces, from which they can maintain a strong fire of the enemy until the lighter pieces and the columns of attack are brought into action. These positions should be taken on the flanks of the ground occupied by the assailant, or the center, if more favorable to the end to be attained. In all cases, wide intervals should be left between the heavy batteries and the other troops; in order that the latter may not suffer from the return fire which the assailed will probably open on the batteries. For the same reason, care should be taken not to place other troops behind a point occupied by a battery, where they would be exposed to the return fire of the assailed; when this cannot be avoided, the troops should be so placed as to be covered by any undulation of the ground; or else be deployed in line to lessen the effects of the shot.

156. The artillery which moves with the columns of attack, should be divided into several strong batteries; as the object in this case is to produce a decisive impression upon a few points of the enemy’s line; by bringing an overwhelming fire to bear upon these points. These batteries should keep near enough to the other troops to be in safety from any attempts of the assailed to capture them. Their usual positions will be on the flanks and near the heads of the columns of attack; the intervals between the batteries being sufficient for the free maneuvers of the other troops, in large bodies. The maneuvers of these batteries should be made with promptitude; so that no time may be lost for the action of their fire. They should get rapidly over unfavorable ground to good positions for firing, and maintain these as long as possible; detaching, in such cases, a few pieces to accompany the columns of attack. In all the movements of the batteries, great care should be taken not to place them so that they shall in the least impede the operations of the other troops.

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Mahan’s Outpost Main Page
Chapter Introduction
Chapter I – Tactics
Chapter III – Positions
Chapter IV – Advanced-Guards and Advanced-Post
Chapter V – Reconnaissances
Chapter VI – Detachments
Chapter VII – Convoys
Chapter VIII – Surprises and Ambuscades