TENAILLE, in fortification, a kind of outwork, resembling a hornwork, but generally somewhat different; for, in stead of two demi-bastions, it bears only in,fi-ont a angle between the same 'without flanks"; and the sides are parallel. Tenaille, dotible or flank ed, is a work whose front consists of four faces, "making two re-entering' angles, and three saliant ; the wings or sides of this work being in like manner corre spondent in the front of the gorge; Tenaille simple, a work having its front formed by two faces, which make a re enteringangle, the sides running directly parallel from the head to the gorge. Te• naille of the place, is that which is com prehended between the points of twa neighbouring bastions ; that is to say, the curtain, the two flanks that are raised on the curtain, and the two sides of the bastions which face one another ; so that it is the same With what otherwise called the face of the fortress. Tenaille
of the foss, is a low work raised before the curtain in the middle of, the doss :it is of thrye sorts; the 'first is compOsed of a curtani,..two flanks, and two faces; the rampart of the curtain, including the parapet and, talus, is but five fathom thick, but the rampait ot the flanks and faCes is seven. The secon'd is compbsecl only of two faces made on tfte lines of de fence, whose rampart and facts are paral lel. The third sort Aiffers -from the second only in this, that its rampart is parallel to the curtain of the place. All three sorts are good, and cannot be hurt by the besiegers' cannon, till they are masters of the covert way, and have planted their cannon there.