The Berm is a space, or path, sometimes left between the exterior slope of the rampart, and the ditch. It serves as a communication round the works, and prevents the earth falling into the ditch.
The Tablette is a flat coping-stone, on the exterior of the top of the escarp of whole revetment.
The Cordon is a semicircular projection of stone, whose diameter is about one foot, placed at the top of the slope of the revetment of the escarp.
The Escarp (a) is the exterior slope, or wall of the rampart.
The Counterscarp (b) is the wall, or slope of the ditch, opposite to the escarp.
The Faces of a work (p q) are those parts which form a salient angle, projecting towards the country.
The Flank (q G) is the part of a work so disposed as to defend another; joining the face of a bastion to the curtain, &c.
The Bastion (M L) is a work composed of two faces, and two flanks. Bastions are joined by curtains, and are constructed salient, and with flanks, in order that the whole escarp may be seen, and that a reciprocal defence may be obtained.
Bastions are of various kinds—viz., full (M), empty (L), also flat, detached, demi, and tower bastions.
A Full bastion (M) is when the terreplein occupies all the interior space of the bastion. From the description of this bastion, that of all the others may be ascertained.