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.