If, when not in action, an army is to retreat from a position which it occupies, the movement is usually concealed from the knowledge of the enemy, and, for this purpose, it frequently takes place at night. On such occasions the outposts remain at their stations as long as possible ; and fires are left burning on the ground, as if the army were still in the position.: after it is dark the main body moves off, and the rest of the troops follow by degrees.
The approach of winter, and the necessity of taking repose after the fatigues of a campaign, render it necessary for armies, whether on the defensive or otherwise, to take up positions where they may remain during the season of inaction. These positions, called winter-quarters, should be chosen by the commander of the army on the offensive, so that he may be able to preserve the ground which he has gained ; and by him who is on the defensive, so as to be secure against the attacks of the enemy. The principles by which a choice of quarters is determined are the same as those which regulate the occupation of ground for a field of battle. The quarters should be covered in front and on the flanks by rivers or other natural impediments to the approach of an enemy, or by forts constructed for defence.
A great extent of ground in front is therefore a disadvantage, as some part may be ill-guarded, and liable to be surprised, and the troops will be too much disseminated. If it is traversed by great roads per pendicular to its front, it is also disadvantageous, as the enemy may then easily march into the quarters.
Several battalions of infantry and squadrons of cavalry are quartered in villages along the front of the position; the whole or a division of a company or of a squadron at each place : these posts may be strength ened by redoubts, palisades, or abatis; retrenchments also should be executed, to defend roads by which the enemy may approach, and bridges over the streams should be destroyed. The troops in each of these stations furnish the men necessary to constitute the advanced posts of the chain. A stronger force should occupy villages and towns
within the first chain, and from these are sent such bodies of troops as may be requisite to support those in their front. The great body of the troops ought to be near a central point of the position, in order that succours sent from that body may easily reach any part that may be threatened.
When an army is in quarters, there are established alarm-posts, at which the troops should be appointed to assemble. These are frequently in the vicinity of a fortress, that the corps may be protected by the latter till all have assembled; but they should be in command. ing situations, that, in the event of the enemy attempting a surprise, his movements may be easily seen. Each division, or corps of the army, should have its own alarm-posts, and there should be, besides, the general place of rendezvous for the whole army : the latter place should be so situated that all the divisions may be drawn up there before the enemy could arrive at it, and it should be protected by a fortress which may contain the provisions for the support of the troops.
A system of signals, for day or night, is determined on, by which intelligence may be conveyed to all the different posts, of the approach of the enemy. Should an alarm be given by any outpost of the chain, the bodies of troops which are appointed to support that post take arms, attach the horses to the artillery, and prepare to march imme diately to the point of danger ; but the judgment of the commander, and the information which he may receive from spies or deserters, must enable him to form an opinion whether a demonstration made by the enemy is true or false.
(Bulow, Esprit du Systeme de Guerre Moderne, 1801; Guibert, a'urres Militaires, 1803; Jomini, Prtcis de r.4rt de la Gun-re ou Nouveau Tableau Analytique ; Rogniat, Considerations sur r Art de la Guerre, 1817 ; Lallemand, Trait6 des Opirations Secondaires de lee Guerre, 1825; Yates. Elementary Treatises on Tactics and Strategy.)