For the dimensions, weight, and equipage of a pontoon, see the word [Pontoon].
When bridges are made to facilitate the communication between different parts of the approaches at a siege, they should, if possible, be placed above the town; or the besieged will take advantage of the current to float down large trees, or other bodies, in order to destroy the bridge. Two of such bridges should always be placed close to each other, in order to prevent the confusion of crossing and recrossing on the same bridge; the one being intended to pass over one way, and the other to return. Pontoon bridges will generally not support a greater weight than 4 or 5,000 pounds. Pontoons, when united as a bridge, will no doubt bear more in proportion, than when acted upon separately: but the weight which a pontoon will bear may be easily ascertained, by loading it with water till it sinks to any required depth, and then by calculating the number of cubic feet of water it contains, ascertain the number of pounds required to sink it to that particular depth.
C amp—With some trifling variations, camps are formed after the same manner in all countries. This principle seems general, that there should not be more ground occupied by the camp of a body of men, in front, than the extent of their line when drawn out in order of battle. Intervals are however generally left between battalions of infantry of about one eighth their front, and between squadrons of cavalry of thirty or forty paces. An army is sometimes encamped in two lines, and sometimes in three; the distance between the lines varies according to the face of the country, from 200 to 600 yards, or more.
In the distribution of the front of a camp, two feet are generally allowed for every file of infantry, and three feet for each file of cavalry. When the ground will admit of it, the infantry are usually arranged in rows perpendicular to the front; each row containing the tents of one company; and the cavalry in the same position, each perpendicular row containing the horses of a troop.
The grenadiers and light infantry are usually placed in single rows on the flanks, and the battalion companies in double rows.
A single row, or one company, occupies in front, nine feet; and a double row, or two companies, twenty one feet, if formed of the old pattern rectangular tents, which hold only five men each. But if the new bell tents are used, 15 feet must be allowed for a single row, and 30 feet for a double row in front.
In the cavalry, a row or troop occupies in front as follow:
| Old Tents. | New Tents. | |||
| Tent | 3 | yards. | 5 | yards, |
| From the front pole of the | 3 | 3 | ||
| tent to picket rope | ||||
| For the horse | 6 | 6 | ||
| For the dung | 2 | 2 | ||
| 14 | yards. | 16 | yards. | |
The breadth of a row in front, whether of infantry or cavalry, being multiplied by the number of rows, and the product subtracted from the whole extent of front for a battalion of infantry, or a squadron of cavalry, will leave the space for the streets, which are generally divided as follows:
| For the infantry, | 59½ | feet each. |
| For the cavalry, | 30 | feet each between the tents. |
| ” ” ” | 46 | feet ” ”horses. |