Faces, of any work, in fortification, are those parts where the rampart is made, which produce an angle pointing outwards.
Face prolonged, that part of the line of defence rasant, which is terminated by the curtain, and the angle of the shoulder.
Fascine. See [Fascines].
Fausse bray, is a low rampart going quite round the body of the place; its height is about 3 feet above the level ground, and its parapet is about 3 or 4 fathom distant from that of the body of the place. These works are made at a very great expence: their faces are very easily enfiladed, and their flank of course is seen in reverse: the enemy is under cover the minute he becomes master of them; and a great quantity of shells which may be thrown into them, and must of necessity lodge there, will go near to make a breach, or at worst to drive every one out. Hence they are liable to do more harm than good, and contribute no way to the defence of the place. M. Vauban only makes them before the curtains, and as such calls them tenailles.
Flanks, in fortification, are, generally speaking, any parts of a work, which defend another work along the outsides of its parapets.
Flank of the bastion, is the part between the face and the curtain; the flank of one bastion serves to defend the ditch before the curtain and face of the opposite bastion.
Flanking, is the same thing in fortification, as defending.
Retired flanks, are those made behind the line which joins the extremity of the face and the curtain, towards the capital of the bastion.
Concave flanks, are those which are made in the arc of a circle.
Direct, or grazing flank, is that which is perpendicular to the opposite face produced, and oblique or fichant, when it makes an acute angle with that face.