Fickt 
¥ ectifixa- 
tere 
—ye 
Piate 
OcLVIU. 
Pig 5 
The redan, 
Redoubt. 
The num- 
ber of mea 
necessary 
for different 
kinds of 
works. 
498 
400 or 500 feet. The. saliant, angles) are.always to be 
pong and dead angles, or points, that cannot be 
seen trom any other part of the work,.as much as pos- 
sible avoided. To render the faces more nearly paral- 
lel to the field, the saliant angle should. be very \ob- 
tuse, and its defence will be considerably improved, if, 
instead of furming an angular point, it be. truncated, 
rounded, or serrated, These diferent forms are repre- 
sented in Fig. 5. A, B,C. Saliants, like», where the 
faces cousist of a suite of small saliant angles, are useful 
in removing all unflanked angles; but the sides, form- 
ing each of the small saliants, ought never to exceed two 
feet ; when they are more than this, they, either weaken 
the parapet, or. they render it necessary to increase its 
chickeaee which both adds to the expense, and en- 
croaches on the room within. Perliaps, upon the'whole, 
the best form of a saliant is the circular represented by 
B. With these general remarks, we shall now proceed 
to enumerate the principal works employed in field for- 
tification, 
The redan is a work consisting, of two faces, like a 
demilune, sometiines also having flanks, in which case 
it is called a piece, , As the redan has an open gorge, it 
is easily taken in rear, and. is therefore never but 
to cover a road, dyke, village, castle, or other work. 
sree eo snes eonennennnerate 
ing a com enceinte, It is. generally triangular, 
aie or circular, and sometimes also a polygon. The 
form is seldom used, indeed, its angles being 
too acute, andthe within |too. small. ..'Phe.circu- 
lar redoubt encloses a large space, Lut is difficult to con- 
struct, and cannot be well fanked. The square, or pen- 
tagonal form, is therefore most commonly. used. 
As a redoubt is liable to be attacked.on. every side, 
its size ought to beso rtioned to the number of the 
arrison, that it may be defended on all sides at once. 
“o be sufficiently defended, a side. will require a man 
to every yard, and three ranks.of men. » The first! rank 
fires, the second loads, and the. third acts as a body of 
reserve. la 
The weak defence of such works generally arises 
from the net Capone of the men who are to defend 
them, an erefore great care is necessary in accom- 
modating the work te the number of the ison, A 
redoubt, whose side is about. 12, yards in length, will 
inclose 36 square yards, but will contain. men; enougly 
only for one rank along the parapet, and is besides much 
ex to the destructive effects of stone balls and 
shells. This is, therefore, the smallest redoubt that 
ought ever to be constructed; if the side be 14 to 16 
yards, the space within will be 60 to 80 yards, 
and will contain men sufficient for one ne ad 
serve. A side of 18 to 20. yards will afford room for 
144 men, being enough for two ranks, and, in general, 
the more the mY SYR ER the greater 
in tion will be the room. aff for the garri« 
son. This is to be understood, however, only of isola~ 
ted works, as those to which succours can be readily af- 
forded, <lo not require to be increased at this rate. If 
the side of the t exceed 30 yards, there will be 
accommodation within for 500 men, of which 384 will 
be sufficient for a complete defence. In this ease, there- 
fore, the redoubt may be constructed with flanks; and, 
if guns are to be planted upon it, it may also have out-. 
works, The general rule for determining the fire lines 
of redoubts, is to allow three men to eight square yards 
of interior room, if the garrison ex 
if less, one man to two square yards. Redoubts are of 
great use in preserving a communication with advan. 
Sorts. . Stay forts, or forts: ad tenaille, are such as form 
s 90 men ; but, . 
PORTIFICATION, 
ced posts, and defending a defile, 
river, a frith, or even the wings of an army ; 
are also very defective in some 
peer and ~ 
rapet. " may 
such a situation that their saliants 
A JSortin, or (field fort, resembles a redoubt, but is 
larger, and has a greater variety of forms. It is called 
a fort when isolated, and.a téte when the gorge is pla+ 
ced upon a river, defile, &c. When forts are not irre- 
gular, which is, however, in many: cases, the most ad+ 
vantageous form, they are either star forts or bastion 
a 
suite of saliantiand. re-entering angles. They 
Forts, 
Star forts, 
may be considered as polygons, whose sides are broken 
so as to form the re-entering angles. If possible, the 
saliant angles should never be less than 60 es, and 
the nearer they approach to 90 the better, asa rectangu< 
lar defence is always the best. .The brisures, or faces, 
forming the re-entering angle, should not be less than 
50 feet, nor more than 100. If they are longer than this, 
they require a numerous garrison to defend them, and 
it would. therefore be better, in such cases, to con- 
— a small fortress, especially if guns are to be 
u R ; 
Star forts are seldom constructed either in the triangu- 
lar or square form, a redoubt being almost always pre- 
ferable to either: Iiniabtriengle thete can be no bri- 
sures, in a square theirangles are 150 degrees. “A 
tagon is somewhat superior to both, the defence of its 
saliant _— being better, and the angles of the bri 
sure 182 degrees, » The hexagon is still better than the 
pentagon, though its saliants are by no means well de« 
fended, The eptagon has saliant angles of 128 des 
grees, and those of the brisures 112. This form might 
therefore be used with considerable advantage, were the 
construction not so difficult; the most convenient, how- 
ever,-as well as: the most advantageous polygon for 
works of this kind, <_< . The construction 
is made either upon the interior , by placing 
equilateral triangles on its sides, ph ae pp thee side, 
by means of the perpendiculars from the saliant andre- 
entering angles. vet Fo WEWO 
Bastion forts have frequently been ; but in 
eral they are inferior to star forts. The triangi 
ilf-bastion is peculiarly defective. They are 
to construct—the saliants are too acute and ‘ill-defend. 
ed—the faces of the demi-lunes are without any cover, 
and the interior surface is too small. The square half- 
bastion is little’ better than the tri , but it in. 
closes a larger When the bastions are full, the 
work may sometimes be very advantageous, and the 
construction is the same as in permanent fortification. 
In bastion forts the sides should not be less than 100, 
nor more than 200:yards, that the flanked may be 
within musket shot.:  P 120 yards is a mes. 
dium. | The best form of the curtain is to break it twice, 
by which a very advantageous fire is obtained.’ 
The principal things to be considered in field forti- 
fication are the nature of the ground, and the soil to be 
Bastion 
vf forts. 
used, the attack that is likely to be made, the relative 
importance of the place, and the number of the garri- 
son. 
When the place is to be defended against small arms 
only, the talus may be as steep as'possible, from the 
summit of the parapet to the bottom of the ditch; the 
base being equal to the height. ‘If guns are to be used, 
the slope should be , to make a better defence. 
The base, in this case, may be one-third of the height, 
The talus 
or slope. 
