FORTIFICATION. 
594 
the time that can be fpared to throw them up, and to the 
fhcngth of the enemy who are to make the attack. The 
following are what have been molt recently pradtifed on 
feveral emergencies, and the rate at which men ordinarily 
work on fuch occafions, arranged in the following table: 
L ■■■ 
Breaft-work. 
Ditch. 
Expence. 
Thickucfi 
Heieht 
Height 
Upper 
Lower 
Solid 
Days’ 
at top 
within 
without 
breadth 
breadth 
content 
work 
4 feet 
72 feet 
6 feet 
8 ft. 
ft. 
s 
4$ ft 
I 
5 
7 s 
6 
IO 
52 
l k 
6 
7 k 
6 
I 2 
4 
6 
8 
2 
7 
Ik 
6 
14 
y* 
IO 
^ 1 
2 2 
8 
Ik 
6 
l6 
si 
7 
I 2 
3 
9 
n 1 
72 
6 
18 
r, 
72 
15 
•3 — 
32 
V 
-- 
The day’s work here is one yard in length. In the 
firft, one hundred men will complete one hundred yards 
in length of this kind of lines in one day; two hundred 
men in haJf a day; four hundred men in a quarter of a 
day, and fo on. 
When lines are thrown up at leifure, then the ditch is 
ufually eighteen feet broad at top, (even or eight feet 
deep, and the Tides of the ditch are To doped, as to leave 
only (ix feet breadth at bottom ; the breaft-work, or pa¬ 
rapet, is about feven feet thick on the top or crown, and 
feven or eight feet high. In the Fortification Plate I. 
thefe line, Tare projected ; where fig. i. Thews the heights, 
depths, ai.d breadths, of the line, and of all its members, 
viz. IL reprefents the ground line, or furface of the 
place. AB, the breadth of the ditch at the top. CD, 
the breadth of the ditch at the bottom. FAC, is the 
dope or fcarp of the parapet and ditch. DBK, is the 
counterfcarp. EF, the top or crown of the parapet or 
breaft-work. EG, the inner dope of the parapet. FIG, 
the top of the foot-bank. HI, the dope of the foot-bank. 
BKL, a fmall doping bank called the glacis. 
The foregoing figure is called a fedtion or profile, and 
may be thus drawn : ift. In the ground-line, lay off, from 
any fcale of equal parts, the diftances I a—6 feet, <36—4 
feet, be— 1 i ft. cd—~] ft. fifA—4^ ft. Af—6 ft. fg=:6 ft. 
£B=:6 ft. B 1,2225 ft. 2d. Through a, b, c, d, e, J, g, B, 
draw lines perpendicular to IL. 3d. Make aH=2% feet 
—bG, cF,—7 ft. dF=i6 ft. /C—8 ft. 2225D. 4th. Draw 
IA, HG, GE, EF, FAC, CD, DB, which continue till 
it meets the line FL, and the profile is conftrudled. 
When lines are made to Cover a camp, or a large trad! 
of land where a confiderable body of troops are pofied, 
the work is not made in one ftraight or uniformly bend¬ 
ing line ; but at certain diftances, the lines projecting in 
faliant angles toward the enemy. Thefe projections, fa- 
liant angles, are called redans or fankers ; becaule the 
tire from them takes the enemy in flank or Tideways as 
they march to attack the lines. The diftance between 
jhe faliant angles of the flankers is ufually between the 
limits of 200 and 260 yards; the ordinary flight of a 
mufket-ball point blank, being generally within thofe li¬ 
mits; although mufkets a very little elevated, will do 
effectual fervice at the diftance of 360 yards. 
A flanker or redan confifts of two lines, called faces, 
meeting in a point, and forming an angle called the faliant 
angle , or flanked angle. The part of the line between 
two adjacent flankers forms the curtain. The gorge of a 
flanker is the diftance between its faces taken at their in- 
terfedlion with the curtains. In the engraving, fig. 2, 
fhews thofe parts : CAB, cab, are redans or flankers. 
AC, AB, ac, ab, the faces. CB, cb , the gorges. AD, 
ad, the capitals. B b, the curtain. The angle CAB, cab, 
the faliant, or flanked, angle. The diftance of the fa¬ 
liant angles is about 240 yards on a mean. The length 
of the capital is ufually between forty and fifty yards. 
The length of the gorges is alfo about fixty or feven ty 
yards. 
To CONSTRUCT A PLAN OF LlNES WITH REDENTS', 
or Redans. —Let the line EEEE, in fig. 3, be fo 
drawn, if poifible, that wherever there is a bend or angle^ 
it may be either at once, or twice, or thrice, &c. the length 
of about 240 yards from one another, whereby a redan will 
always be where .there is an angle.—In this line lay off 
diftances of 240 yards each, as from E to E, E to E, See'. 
reckoning from the bends toward each end, whether it 
happens that the line will or will not be exadlly meafured 
by a repetition of the 240 yards. At each point E draw 
the capital EF in a perpendicular pofition to the direction 
of the line in that point, and make the capitals about 
forty or fifty yards long. On each fide of E fake the 
half gorge, EG, EG, each tf about thirty'or thirty-five 
yards, and draw the facet FG, FG; and the out-line, or 
majler-line of the curtainshmd redans are formed. Parallel 
to each curtain and pace draw lines, within, at the diftances 
from the majler-line of feven feet, eight feet, twelve feet, 
and eighteen feet. Then the breadth of feven feet re- 
preferits the plan of the parapet.-, of one foot, its inner 
dope; of four feet, the top of the foot.bank ; of fix feet, 
the foot-bank (lope. 
On the outlide of the mafer-linc, draw lines at the 
diftances of io|, i6|, and feet, parallel to each cur¬ 
tain and face ; and thefe will reprefent the plans of the 
fcarp, ditch, and counterfcarp ; obferving that the faliant 
angles of the counterfcarp are rounded before the angles 
of the redans. When the plans are drawn from a large 
fcale, all the lines before mentioned are drawn ; but when 
the plan is drawn from a fmall fcale, as of twenty yards 
or more to an inch, then the plan is ufually reprefented 
by four parallel lines : one without tire mafter-line, re- 
preleming the counterfcarp or out-line of the ditch ; and 
two within, reprefenting the breadths of the parapet and* 
foot-bank. 
Of BATTERIES. 
When lines are to be vigoroufly defended againft nrr 
approaching enemy, it is proper to raife batteries ; that is, 
works from which cannon may play on the troops as they 
advance to the attack: thefe batteries are either open or 
covered. An open battery is only a number of cannon, ge¬ 
nerally field-pieces (that is, fuch as carry a ball not exceed¬ 
ing nine pounds weight), ranged abreaft of one another, on 
Tome natural elevation of the ground, or an artificial bank 
of about a yard or two high. Thefe cannon are ranged 
at about fifteen feet diflunt from one another, having 
their loading utenfils lying by their fide ; and the powder 
lodged at Tome diftance behind the battery. A lefs dif¬ 
tance than abont fifteen feet from gun to gun might occa- 
(ion danger, confidering the hot fervice for which fuch 
batteries are eredted. 
A covered battery is when the cannon and gunners are 
covered by a bank made of britfhwood, faggots, and 
earth ; of about eighteen or twenty feet thick, and feven 
or eight feet high. The cannon ufed in fuch batteries 
are generally front nine to eighteen pounders; though 
fometimes twenty-four pounders are ufed in them. The 
faggots, or, as in this fcience they are moll ufually called, 
the fafcincs, are made of the rhiddling-fized loppings of 
trees, and are of three different lengths, lix, nine, and 
twelve, feet, according to the work they are intended for. 
They are fixed to the ground, and to one another, by 
(takes called pickets ; about an inch and a half thick, and 
from three to fix feet long. 
In field fortification, the batteries conlift of four chief 
parts, namely, the ditch, the parapet, the platform, and 
the magazine. The ditch is ufually dug in the front and 
(ides, and fometimes quite round ; and ferves not only to 
furnifh the earth neceffary for the parapet, but it alfo 
prevents the enemy from entering the battery fo readily 
as he might otherwife do. The ditch in front is com¬ 
monly 
