Coffer

In fortification, a hollow lodgment, sunk in the bottom of a dry ditch, from 6 to 7 feet deep, and from 16 to 18 feet broad. Its length corresponds with the whole breadth of the said ditch, from side to side. The besieged generally make use of these coffers to repulse the besiegers when they attempt to pa the ditch; they are distinguished only by their length from caponnières . They are covered with joists, hurdles, and earth, raised 2 feet above the bottom of the ditch, so as to serve the purposes of a loop-holed parapet.