It has been proposed by some to cover the glacis with 
stones, or plant it with brush-wood, to prevent the ene- 
my from making excavations. Perhaps the same pur- 
would be better accomplished by planting it with 
This last method was adopted by the French en- 
subsequently to 1792. Another improvement 
ey denartetitn Ceahs'ytacks is to round off all the 
ought to look towards the 
bastion, because, if it were on the opposite side, it would 
be to the enemy’s fire, whenever oan dae: 
session of the saliant angle of the ravelin. The com- 
munication between the covered way and the ditch is 
formed by ramps in the counterscarpe of the places of 
arms. 
Such is a general outline of a complete fortification 
ing to the modern system of defence. A fortified 
place, however, when finished, seldom presents so sim- 
ple a form as what we have now described, being gene- 
rally surrounded with a great variety of other outworks. 
The nature and use of these we shall now proceed to 
A tenaillon is a kind of couvre face A, Fig. 4. construct- 
ed on each sideof a small ravelin B, toincrease its strength, 
and cover the shoulder of the bastion. To trace a tenail- 
lon, ce the face of the ravelin, and, leaving from 
60 to 80 feet for the fossé, set off ab equal to 180 feet. 
On the coun’ of the bastion, set off cd equal to 
90 feet, and ab dc will be the tenaillon. Works of this 
kind are sometimes a little different from that repre- 
are in consequence seldom 
et been sometimes before 
the ravelin; but the 
PLATE 
iH por 
| aa 1, 
before th seteduidioeree: 
ph igh ct ce ehetthety gor tm 240 feet, and CDabout 
g 
: 
: 
it may 
with the covered 
A 
we ete eer ; 
Coun’ 
~ 
FORTIFICATION. 
493 
When there is a scarcity of earth, a ditch is some- Permanent 
times constructed before the covered way, or rather be-  Fortifica- 
fore the glacis, called the avant fossé. It is not, how- SS) 
ever, of much use, unless it can be made wet and dry ayant 
at pleasure, and is rather incommodious to the soldiers fossé. 
when making a sally. 
The avant-covered-way is a second covered way be- Avant- 
fore the first-or before the avant-fossé; but is useful covered - 
only in large fortresses, which have numerous garrisons. *Y: 
It is constructed in the same way as the first, care being 
taken that the fire of the latter is not interrupted b 
the former. The avant-covered-way communicates wit 
the works behind by means of bridges or caponniers, 
the inner extremity of which terminates in the places 
of arms. 
Fleches are works of two lines or faces, forming an fteches. 
angle, and generally constructed over saliant angles. 
ey are sometimes useful in covering a passage, but 
in ne they are incapable of making any resistance. 
unettes are works resembling ravelins, but consist- Lunettes. 
ing only of a parapet, placed opposite the saliant angle Prats 
of the cov way, as H and K, Fig. 1. If the cover- a 8 
ed-way has an avant-fossé, the lunettes are placed in Poel 
the fossé ; but if it has none, they are constructed at 
the foot of the glacis, as H and K, Fig. 1. When 
surrounded a ditch and covered-way, they form 
an excellent defence; and, by obliging the enemy 
to open his works at a greater distance from the place, 
they essentially prolong the siege. They are also uses 
ful in sorties. 
Lunettes ought-not to be placed too far from the en« 
ceinte ; their angles should be at least 60 degrees, that 
it sauyibe-defiesiod by guns; and the faces from 100 
to 200 feet long. are always of the greatest ad- 
vantage, when the angles of the bastions are very open. 
The most advantageous arrangement of lunettes, and 
that by which they best defend one another, is where 
the straight lines joining them make saliant and re-en+ 
tering angles alternately ; the saliant before the ravelin, 
and the re-entering before the bastion. In this way, 
too, the greatest number can be made to defend one 
bastion, all which must be taken before the bastion it. 
self be assaulted. Flanks of from 50 to 60 feet are ne« 
in lunettes. The angles of these flanks increase 
as that of the bastion diminishes, and vice versa. 
The communication between the lunette and the co- 
vered way, is by means of caponniers; but lest these 
rh subterraneous pas- 
of covered way, to the 
If the communica- 
tion is not covered, it enters the gorge by steps; if it 
is subterraneous, the gorge is and the steps 
are in the middle of the lunette. the terre-plein of 
the lunette is not higher than the ground, gorge 
by a wall with loop-holes, at least 
i The covered 
A horn work is ted by ABCD, Fig. 2, and Horn 
is constructed as follows. From the saliant ce works. 
the capi ing EF from 450 to 500 feet. hy Fig. 2 
F draw a icular BC, ing BF, CF each 
from 300 to 350 feet, and on this line construct a 
front, as on the exterior side of the polygon. Then 
draw the BA, CD directed to a t, about 30 
feet from the shoulder of the bastion. If aravelin abe 
is constructed before the horn work, its faces ought to 
be 200 feet. ‘The ditch round horn works is about 72 
feet. Various entrenchments, as Gand H, have been 
