Frederick Engels. Barbette
In a battery, guns are said to be placed en barbette when they stand high enough to fire over the crest of the parapet instead of, as usual, through embrasures. To raise the guns to this height, various means are adopted. In field fortifications, an earthwork platform behind the parapet forms the station for the gun. In a permanent fortification, the common high sliding carriage or the traversing platform raises the gun to the required level. Guns placed en barbette have not the same cover from the enemy's fire as those firing through embrasures; they are, therefore, disposed in this manner where the parapet cannot afford to be weakened by the cutting of embrasures, or where it is desirable to extend their range more to the right and left than would be possible with embrasures. On this account, guns are placed en barbette in field fortifications; in the salient angles of works; and in strand batteries destined to act against ships, especially if the parapet is of masonry. To protect them from enfilading fire, traverses and bonnets are constructed when necessary.