Part 26 (1/2)

COUNTERSCARP, is the casing of the ditch which is opposite to the defence.

DEMI-LUNE, low work, disposed before a curtain between two bastions, separated from the main body of the fortress by a ditch, and possessing two faces and two short flanks (see p. 306).

DONJON OR KEEP, chief retreat of the defenders of a strong castle. The donjon was always separated from the defences of the castle, and put in direct communication with the exterior (see p. 169).

ESCARP is that part of a revetment of fortifications which fronts the exterior, from the bottom of the ditch to the parapet or crenelation.

FAUSSE-BRAIE, palisade or trench, with parapet, defending the bottom of the ditch, low enough to be masked by the relief of the counterscarp.

GLACIS, sloping ground which extends from the counterscarp of the ditch towards the country, and masks the covered ways as well as the escarp.

h.o.a.rDING, wooden gallery which in time of war was put outside crenelations to enable the defenders to see the foot of the ramparts and towers, and to throw stones and materials of all kinds upon a.s.sailants attempting to approach.

LIST, interval left between the exterior defences and those of the body of the place (see p. 180).

MACHICOULIS--The wooden h.o.a.rding being easily set on fire, it was replaced in France, about the end of the thirteenth century, by stone corbels carrying a crenelation of masonry, and leaving intervals between them for throwing materials upon the a.s.sailants who approached the foot of the walls. In Syria, the Christians had adopted the machicoulis as early as the beginning of the thirteenth century.

MANGONEL, engine for propelling large stones from a kind of sling attached to the longer arm of a movable beam heavily weighted at its other extremity.

MERLON, solid s.p.a.ce in the parapet between two embrasures. During the Middle Ages the merlons were usually perforated in the middle by a loop-hole. In time of war the battlements were masked by mantelets of wood, which could be raised at discretion by means of an axle turning in two iron collars let into the upper angles of the merlons.

MOVABLE TOWER, timber tower which was mounted on rollers and was advanced to the walls for the purpose of a.s.sault. The movable towers were made to command the battlements, and the upper story was furnished with a bridge which fell upon the crest of the ramparts of the towers (see p. 218).

OISEAU, in the fifteenth and sixteenth centuries, a small masonry work which, disposed at the salient angles in the ditch, swept the latter and was intended to bar the pa.s.sage. The _oiseaux_ were masked by the counterscarp. In modern polygonal fortifications this plan has been re-adopted (see p. 373).

OPPIDUM (Latin), a citadel or fortified strategical position, among the Gallic populations. Many Roman camps were formed at the epoch of the conquest of Gaul, on the Gallic _oppida_, which were only a kind of intrenched camps formed upon elevated plateaux. Several of our French towns occupy the sites of ancient _oppida_--Langres, Laon, Beziers, Carca.s.sone, Uzerche, Sainte-Reine (Alesia), Le Puy-en-Velay, Semur-en-Auxois, Avalon, Puy d'Issolu, &c.

ORILLON, projecting part of faces of bastions, intended to mask the flanks and to s.h.i.+eld the guns which arm these flanks (see p. 280).

PARADOS, mound of earth disposed behind the guns in battery, to shelter them as well as the servers from reverse firing.

PARALLEL, trench parallel to the sides of the polygon of a fortress, supplying a covered communication for planting and serving the siege batteries. Formerly these parallels were required for approaching and planting the breach batteries. These parallels communicated with each other by trench boyaux traced in zigzags, so as not to be raked by the fires of the place (see p. 330).

PAReCLAT, epaulment of earth, or formed with gabions raised on the ramparts, or in the middle of bastions, to shelter the defenders from the splinters of bombs and sh.e.l.ls.