A bivouac is the most simple kind of camp. It consists merely of lines of fires, and huts for the officers and soldiers. These huts may be made of straw, of wood obtained from the forest, or by dismantling houses and other buildings in the vicinity of the camp, and stripping them of their timbers, doors, floors, &c. Troops may be kept in bivouac for a few days, when in the vicinity of the enemy, but the exposure of the soldier in ordinary bivouacs, especially in the rainy seasons or in a rigorous climate, is exceedingly destructive of human life, and moreover leads to much distress to the inhabitants of the country occupied, in the destruction of their dwellings and the most common necessaries of life. If the position is to be occupied for any length of time, the huts should be arranged like tents, according to a regular system, and made comfortable for the troops. Such should always be the system adopted in camps of practice or manœuvre, in cantonments, winter-quarters, or in intrenched positions.
We have adopted in our service the system of encamping in tents. These may do very well under the ordinary circumstances; but in the active operations of a campaign they are exceedingly objectionable, as greatly encumbering the baggage-trains. It would seem preferable to resort to bivouacs for the temporary camp of a single night, and to construct a regular system of huts where a position is to be occupied for any length of time. This may be regarded as a general rule, but in certain countries and climates, the tent becomes almost indispensable.
Napoleon's views on this subject are certainly interesting, if not decisive of the question: "Tents," says he, "are not wholesome. It is better for the soldier to bivouac, because he can sleep with his feet towards the fire; he may shelter himself from the wind with a few boards or a little straw. The ground upon which he lies will be rapidly dried in the vicinity of the fire. Tents are necessary for the superior officers, who have occasion to read and consult maps, and who ought to be ordered never to sleep in a house—a fatal abuse, which has given rise to so many disasters. All the European nations have so far followed the example of the French as to discard their tents; and if they be still used in camps of mere parade, it is because they are economical, sparing woods, thatched roofs, and villages. The shade of a tree, against the heat of the sun, and any sorry shelter whatever, against the rain, are preferable to tents. The carriage of the tents for each battalion would load five horses, who would be much better employed in carrying provisions. Tents are a subject of observation for the enemies' spies and officers of the staff: they give them an insight into your numbers, and the position that you occupy; and this inconvenience occurs every day, and every instant in the day. An army ranged in two or three lines of bivouac is only to be perceived at a distance by the smoke, which the enemy may mistake for the vapor of the atmosphere. It is impossible to count the number of fires; it is easy, however, to count the number of tents, and to trace out the position that they occupy."
The guarding of camps is a very important matter, and requires much attention.
The camp-guard consists of one or two rows of sentinels placed around the camp, and relieved at regular intervals. The number of rows of sentinels, and the distance between each man, will depend upon the character of the ground and the degree of danger apprehended.
Detachments of infantry and cavalry, denominated picquets, are also thrown out in front and on the flanks, which, in connection with the camp-guards, serve to keep good order and discipline in and around the camp, to prevent desertions, intercept reconnoitering parties, and to give timely notice of the enemy's approach.
Still larger detachments, denominated grand-guards, are posted in the surrounding villages, farm-houses, or small field-works, which they occupy as outposts, and from which they can watch the movements of the enemy, and prevent any attempts to surprise the camp. They detach patrols, videttes, and sentries, to furnish timely notice of danger. They should never be so far from the camp as to be beyond succor in case of sudden attack. Outposts, when too far advanced, are sometimes destroyed without being able to give notice of the enemy's approach.
In encamping troops in winter-quarters, it is sometimes necessary to scatter them over a considerable extent of ground, in order to facilitate their subsistence. In such a case, the arrangement of guards requires the utmost care. A chain of advanced posts should be placed several miles' distance from the line of camp; these posts should be supported by other and larger detachments in their rear, and concentrated on fewer points; and the whole country around should be continually reconnoitered by patrols of cavalry.
The manner in which Napoleon quartered and wintered his army on the Passarge, in 1806-7, furnishes a useful lesson to military men, both in the matters of encampment and subsistence. An immense army of men were here quartered and subsisted, in a most rigorous climate, with a not over fertile soil, in the midst of hostile nations, and in the very face of a most powerful enemy.
A Roman army invariably encamped in the same order, its troops being always drawn up in the same battle array. A Roman staff-officer who marked out an encampment, performed nothing more than a mechanical operation; he had no occasion for much genius or experience. The form of the camps was a square. In later times, they sometimes, in imitation of the Greeks, made them circular, or adapted them to the ground. The camp was always surrounded with a ditch and rampart, and divided into two parts by a broad street, and into subdivisions by cross-streets and alleys. Each tent was calculated to hold ten privates and a petty officer.