A Military Dictionary and Gazetteer / Comprising ancient and modern military technical terms, historical accounts of all North American Indians, as well as ancient warlike tribes; also notices of battles from the earliest period to the present time, with a concise explanation of terms used in heraldry and the offices thereof. The work also gives valuable geographical information. Compiled from the best authorities of all nations. With an appendix containing the Articles of war, etc.

by Thomas Wilhelm

Military bridges are composed of a roadway and its supports; the first consists of beams or balks reaching across the adjacent supports, and covered with plank called chess.

The supports, from which the bridge takes its name, may be either fixed, as trestles, gabions, carriages, piles, or floating, as pontons, boats of commerce, rafts, etc.

Ponton bridges are preferable to all others when a passage by main force or surprise is to be undertaken. They may be constructed on any stream of sufficient depth; they may be replaced by rafts when the velocity of the stream does not exceed 6 feet per second. In swifter currents the latter are unmanageable, drag their anchors, and are liable to destruction from floating bodies.

Trestle bridges may be constructed in rivers whose depth does not exceed 9 feet, and whose velocity is not more than 6 feet. They may be employed with advantage in rivers of moderate depth and gentle current, with hard, even bottoms. When the bed of the river is uneven the adjustment of the trestles to the bottom is very tedious, and if the current is rapid, almost impossible. When the bed is of mud or fine sand, the settlement of the legs is liable to be irregular.

Gabion bridges are used over marshes and shallow streams. They consist of gabions constructed in the ordinary way, and of a height necessary to give a level road; these are placed in rows perpendicular to the axis of the bridge, are filled with stones, or gravel, and are capped with a piece of timber on which the balks rest.

Pile bridges are superior in point of stability to all other military bridges, but requiring much labor and time in their construction; they are usually restricted to securing the communications in rear of the army.

Bridge-head. A fortification covering the extremity of a bridge nearest the enemy. The French term for the same is [tête du pont].

Bridle. An instrument with which a horse is governed and restrained, consisting of a head-stall, a bit and reins, with other appendages, according to its particular form and uses.

Bridle. In gunnery, the piece in the interior of a gun-lock, which covers and holds in place the tumbler and sear, being itself held by the screws on which they turn.

Bridle, Arm Protect. The term for a guard used by the cavalry, which consists in having the sword-hilt above the helmet, the blade crossing the back of the head, with the point of the left shoulder, and the bridle-arm; its edge directed to the left and turned a little upwards, in order to bring the mounting in a proper direction to protect the hand.