FORTIFICATION; 
m 
the line ZZ in Y; join YR*, and the plan is formed.— 
Or, from X, fig. 12, the faliant angle, with a radius of 
fix times tlie height, fuppofeof 12 yards,»defcribe the arc 
IL ; and with five times the height, or ten yards, defcribe 
the arc KK, cutting ZI in O, and drawn OP parallel ro 
KL. Make XM=t or 3 yards, and draw the curved 
lines MO, MP, which in plans are be done by hand ; or 
eife draw right lines from M to O, and from M to P, and 
the plan of the ramp is completed. 
Or BARBETS. 
It often happens, that by railing the floor of part of a 
battery, the guns placed on it have an advantageous com¬ 
mand over the ground in front of it; and when the guns 
thus railed fire over the crown of the parapet, without 
any embrafures, it is called an Open Battery, Battery 
gn barbe, or a Barbet. Thefe may be made either in a 
Curtain, or at the faliant angle of a flanker. They fhould 
always be about three feet lower than the crown of the 
parapet, and about eight or nine yards broad at the top, 
with a proper Hope to the bafe, of a length fuitable to 
the number of guns to be mounted on them, allowing 
about fix yards for each, with a proper ramp at each end 
to afeend by. This condruftion will be better elucidated 
by referring to the plan and profile projected through the 
line BC, fig. 13, 14, 15, in the preceding engraving.—Let 
PQJRVX, fig. 13, be the common bank of a line, the pa¬ 
rapet of which is RSTV ; the inner Hope RS being about 
fix or feven feet higher than QR : then the bank mnoR, 
jailed fo high that the cannon can fire over the crown of 
the parapet ST, is the barbet, the height of which ap is 
about four feet. 
On the top of the barbet a platform is raifed as in 
other batteries.—Let fig. 14, 15, reprefent part of the plan 
of a line, and one of its flankers, or of a battery condruft- 
ed in fuch a form 5 where A a is the length of the barbet 
or raifed battery, fuited to the number of guns to be 
ufed, which are to be drawn up the ramps put at the 
ends ; the breadths being about nine feet, and the length 
*b about eight yards. 
Of CAVALIERS. ' 
A cavalier is a battery raifed above the other works, and 
covered by a parapet with embrafures. They are con- 
firufted of various fliapes ; fquare, as (hewn at fig. 17, or 
round, as at fig. 16 ; or like a horfe-lhoe, which is the 
Saracen method ; but when they are conftrudled in flank¬ 
ers, as is modly the cafe, as reprefented at fig. 18, they are 
of a like figure to that particular flanker ; leaving a fpace 
.of ten yards or more, between the parapet of the flanker 
and the outline of the cavalier. They fhould be faced 
with earth, or plank, or brick, but not with ftone ; be- 
caufe the fplinters knocked off by the enemy’s cannon 
would greatly annoy the troops that may be polled in the 
line below the cavalier. 
Of TRAVERSES. 
A traverfe is a bank of earth thrown perpendicularly 
acrofs a line, or other work, to prevent the enemy’s artil¬ 
lery from taking that line. Traverfes may be from twelve 
to eighteen feet thick, in order to be cannon proof, and 
their height about 7 feet or more, if the line be expofed to 
any eminence from which the enemy can have a command. 
And to preferve a communication, a paffage of about five 
er fix feet wide mull be left at one end of the traverfe. 
The different ways of condrufting thefe works will be 
jeadily underftood by referring to fig. 19, 20, 21, 22, in 
the engraving. Thus at A, fig. 19, the traverfe is formed 
by two equal Ihort banks, the ends of which jut one be¬ 
yond the other about four feet, leaving a paffage of about 
fix feet. At B, C, and fig. 20, 21, the end of the traverfe 
juts.about two or three feet into the parapet, befide the 
paffage. But as this greatly weakens the parapet, it 
©uglit to be praflifed only in fuch places where there is 
lutficient thicknefs left $ where nothing can be fpared 
2 
from the parapet, the traverfe may be made as at E and 
F, fig. 22. If any part of a work, thus (hut in by one or 
more traverfes, is to be defended by mulketry, as well as 
by cannon, then it is proper to add to the traverfe one or 
more foot-banks for the troops to mount upon, when they 
are to fire over the traverfe, leaving the upper foot-bank 
four feet and half below the crown of the traverfe. 
Of BARRIERS. 
A barrier is a gate or fence ferving to Unit ttp the roads 
or approaches towards works of fortification, in order to 
prevent their being carried by furprife : they are of va¬ 
rious kinds; as,—ill. A ftrong chain drawn acrols the 
paffage at about four feet above the ground, and fattened- 
at each end to an upright pod. 2d. A beam laid hori¬ 
zontally acrofs two upright polls. 3d. A bar-gate hang¬ 
ing by hinges to an upright pod. 4th. A Chevaux de 
frife , or beam cut with fix fides, each of which is armed 
with iron Ipikes let within five or fix incites one of the 
other. This beam is fupported at each end by an up¬ 
right pod. 5th. A Turnflile, which is fure to prevent 
more than one perfon at a time from pading the fame way/ 
6th. A Herrifon, or a chevaux de frife turning horizontally 
on a pod in the middle of a paffage, like a turndile. 7th-, 
Klinkets , or ftrong doors or gates made like palifades, and 
fadened or fecured ir^the interior fide. 8th. Palifades , 
which are conftrufted of draight wooden dakes, nine or 
ten feet long, and about the thicknefs of a middle-lized 
leg, but of a triangular or re< 5 tangular diape, with one of 
their ends pointed. Their ufe is to form a line before 
thofe places that are mod likely to be taken by furprife. 
The bed are thofe made of fpine oak. In planting pali« 
fades it is ufual to fink about three feet of them into the 
ground, the thick end downwards, and the pointed end 
upwards, and to fet them about four inches from one ano» 
ther ; the whole fhould be braced by ftrong pieces nailed 
acrofs them, and fecured by thick pods at the diftance of 
every four or five yards. 
Of REDOUBTS. 
A Redoubt is extremely ufeful to drengthen the lines 
•which flint up or fecure a pafs. They are ufually figures 
of three, four, five, or fix, fides, encompaffed with a ditch 
and a bank of earth. The bank encompading fuch works 
generally confifts of a rampart and parapet, adapted to the 
occalion. The Rampart is a large bank, of a height fuf- 
ficient to cover the habitable parts of the lioufes (if any) 
from a diredl fire of the enemy; or to raife the troop*- fo 
as to command the neighbourhood ; and of a thicknefs 
f ufficient to refid the efforts of an enemy’s cannon for fome 
time. The Parapet confids of a bread-work or bank roiled 
on the rampart clofe to its outer edge, to cover and de¬ 
fend the troops poded behind it, on the rampart. Ob 
thofe fides of the work likely to be attacked, the parapet 
fliould be cut into embrafures and merlons. 
When redoubts are intended to defend lines or intrenefv 
ments, their faces or fronts fhould be fo placed, that the 
fliot difeharged from them may fly diredlly to the front 
of thofe lines; for hereby the enemy may be fo galled in 
flank, as to find it neceffary to attack the redoubts, and 
fo either weaken his attack on the lines, or caufe him to 
lofe time. But when redoubts are built more particu¬ 
larly to defend the fpot on which they dand, their can¬ 
non mud front the places from which they are liable to 
be battered, and alio command the ways by which they 
may be approached. 
To construct a squARE Redoubt— Mark out a 
fquare, the fide of which is adapted to the number of 
troops allotted for the defence; asAB,fig. 23, for the in* 
fide of the rampart; About tlii's fquare, at the didance 
of ten or twelve feet, defcribe another fquare, the fide of 
which, CD, is the inner boundary of the parapet. Make 
a parapet about ten feet thick, the outline of which is 
the line EF ; leave a berm about four feet broad, the fide 
of which is GHj and dig' a ditch about fix teen feet wide. 
