FORTIFICATION. 
it should be a rule never to place an out- 
work so that it could be cut off, without 
receiving aid from some sufficiently strong 
and contiguous part. Were this neglected, 
the enemy would not fail to surround such 
ill judged detachments, and to a certainty 
carry them off during the night. Admit- 
ting this principle, the fleche 9 would be 
subject to the foregoing evil, if there were 
not a strong body of troops stationed in the 
counterguard 7, or the flank of the crown- 
work, from which detachments could be 
sent without delay. 
Lunettes are generally constructed by 
producing their faces at about one half the 
length of the raveline, which they flank at 
right angles ; their own flanks are drawn 
perpendicular to the face of the bastions 
which commands them, generally falling 
about the middle of such face. See the 
lunette s, opposite the bastion D. Some- 
times the lunette is separated, by a narrow 
fosse, from the body of the raveline; in 
other instances, its face joins that of the 
raveline ; the fosse being arched over, and 
a battery placed on the arch, by which the 
ditch of the raveline is scoured. The face 
of the lunette gives a direct fire towards 
the glacis, before the saliant angle of the 
bastion 5. 
Tenaillons, (signifying piercers, or claws,) 
are sometimes made on each side of a ra- 
veline, and even beyond them a small de- 
tached raveline, or a bonnet, is sometimes 
added. The rule for constructing a tenail- 
lon is, to prolong the other face of the ra- 
veline, thereby to make its front, and to 
determine the length of that front, by a 
flank drawn perpendicular to the centre of 
the face of that bastion, before which the 
tenaillon stands ; as is seen in the tenaillon 
R, standing in front of the bastion 4, and 
covering the face of the raveline K. 
Redoubts standing in ravelines, being in- 
tended as a resort for the troops driven 
from the defences of its faces, and requiring 
great strength of defenders, should inva- 
riably be casemated throughout, in the most 
substantial manner; they 'may not only 
mount batteries on their ramparts, which 
should command those of the ravelines 
wherein they are placed, but they may 
be pierced below with abundance of loop 
holes, and with embrasures for cannon, 
provided the ditch be of a sufficient depth 
dnd width to prevent assault, and that the 
interior of the raveline be, as it ought, per- 
fectly level, and contain nothing to conceal 
the enemy : in each redoubt there should 
be a small expence magazine, and in every 
outwork one or more wells should be made, 
if practicable, of sufficient capacity to sup- 
ply plenty of water. 
Redoubts made to flank other works 
can have no fixed rule ; they are generally 
placed to most advantage, and their fronts 
are always disposed towards those parts of 
the exterior, which stand in need of such 
support. In some places, as at Q, they 
are made more to cover a weak point, tlmn 
with any immediate view to protracting the 
assault: the want of a redoubt, or some 
other work, on the other side of the bastion 
O, serves to prove the utility of tiiat at Q ; 
it being evident, that could an enemy’s hat- 
tery be placed any where about C°, C°, 
that is, in a position to batter the bastion 3, 
the greater part of the defences of the 
principal would be subjected to mischief; 
and that, as the approaches should advance 
upon the glacis, the ravelines N, and O, 
would be in a measure cut off from all con- 
nection with the curtains S r, and u v. We 
suppose the crown-work M not to exist. 
We now come to speak of that crown- 
work ; it is a limb of immense importance, 
and should be rendered as strong and effi- 
cient as possible. This kind of fortifica- 
tion is built on various accounts, viz. to 
occupy ground which, being left at the dis- 
posal of an enemy, might prove of consi- 
derable injury to the body of the place ; to. 
enclose buildings that could not be included 
within the principal ; to defend a promon- 
tory, or a projection, covering a harbour ; 
to prolong a line of works, and other causes 
which locality would suggest. When, how- 
ever, a piece of ground, which stands higher 
than could be commanded from the works 
of the principal, is to be occupied, a crown- 
work would be improper : in such case, a 
citadel is advantageously made on the supe- 
rior ground ; observing, that in lieu cf a 
raveline being at N, there should be a com- 
plete defensive face, appertaining to the 
citadel, commanding the works of the for- 
tress, which instead of presenting defences 
along the centre face B C, should rather 
lay open to the batteries of the citadel. 
These latter should command the whole 
interior of the polygon, and be well case- 
mated throughout, for the safe lodgment 
of all the garrison, and for the safe keeping 
of provisions and stores, for six months at 
least. The instances on record of citadels 
holding out for a long time, should render 
