EEG ATION, 
pane are always fuppofed t aie cama up two deep: 
thofe on the banguette never to fire until thofe on the terre 
plein may have lo = d, ex 
In the abov computation, always caft out a fixth 
an of your ces beth artillery and a try, to be in 
referve: the former to replac ce any that may be damaged ; 
the latter : aid — the garrifon may o: hard prefied, 
as well as up vacancies. 
The | interior of a work fhould n 
rer be foc 
y about 220 {quai Thi 
avy ordnance will demand fu t half as 
m 
hat area inp be indif. 
cold Rtwatione s, much lef: 
Interior eee he eres always pain pro- 
defences be oo thereby fo oe as to render 
the garrifon unequal to their maiutena 
* 16. The fub{tance of parapet ae “fold. works muft de- 
pend both on the weight of ae oppofed to, and mounted 
-on, them; the foil will alfo occafion much variety ; but, if 
. t ! 
but 15 will, in moft cafes, be better 
mufketry only need feldom exceed 8 feet: in ma 
pee efpecially where found clay can - oe lefs 
may fuflice he height muft confor cal circum- 
ftances ; obice ving that the bac fhould nee be valle d 
to 43 of the creft, otherwife men of ordinary height could 
saps ae over ina pro manner 
Vv made on the borders of ravines muft be fo 
contended a as to have full amaed down to the bottom of 
every part, and efpecially of all defcents to them from the 
oppofite fide. Such may be very . paca, Pe 
where that advantage does not ier the ditch mu 
dee a 
i} 
as wide and as at leaft _ eda fi co 
the ramparts and ee No ee can be better than 
thofe excavated trom maffes rock, or “obra ugh 
foil, inaccefl:ble towards the front uch are ra see 
reforted to in this branch of for — * Mounds of earth 
may either be cut through for embra fo as to cover 
ae canuon 3 or they may be {carped oar within and with- 
uch manner as to prove admirable ae ee 
the ¢ cannon en‘ barbet a wide range towar anks is 
requilite, this latter ee is highly appropria 
18. In the conftruétion of tetes de pont,’ cer fele& a 
re-entering angle, where an can be lees properly fitu- 
ated. This leg etal the my from 
flanks and re s hei ae es would, if the 
conttructed ne a faliant angle of the flream. Denies ia 
pe former mode, the defenders may line the oppofite banks, 
n both- _ a the bridge, with additional defences, that 
we ay &o e flanks of thofe advancin ng to attack, 
as de as ae abfolutely crofling pa BG bridge, which 
defenees, in-cafe of explofion. If duly funk, and covered 
- Vou. KV. 
firuction o 
by epaulements, and by an a ay a as ee 
on fafcines, &c. refiing on good 
little’ ‘danger éven from the heavieft heiey thie 
maga - 
zines ate face towards that quarter leaft expofed to the 
enem 
For minor parts of os we aed our readers 
to the articles Fascinz, Gasion, Battery, &c. wh 
feveral proportions oa ufes of each ‘vill ie found . 
ailed. ‘Lo conclude this fubje@, we fhall briefly obferve, 
i the ay general ar i which govern in the con- 
f permanent fortifications, apply, fo far as cir. 
euler: may admit, to the pro jection and 2 the raifin ng 
of field-works in Sey The mutual fupport of con- 
tiguous parts muft ever be the principal confideration 
ForTIFICATION is aif ufed for the place fortified : 
ees aie works raifed to defend and flank it, and Keep 
off the enemy. 
All foatiheatibes confift of lines beg ae which have 
various names, according to their vari office: 
The principal angles are thofe of ie ae the flank. 
ing nee ime angle, angle of the epaul 
The cipal aye are thofe of ae a cone 
ee noe of the tal, &c. See each in its pla 
Fortifications are div ided j into regular aud irs ee ‘and 
again into ran ee and es ry. Regular fortification is 
that wherein the battior all equal; or that which is 
built in a ous pal con, i ee and aa whereof are 
aida about a muflcet-fhot from each o 
a regular fortification, t the eal equal, have 
the pete of bein rien! defen ibe fo that there 
are no weak places. i egula r fortification is that wherein 
the baitions are unequal, and _ e; or the fides and’ 
angles not all equal, and equidi 
In an hid eral ss spe pe defence and- ftrength 
being unequal, ther eceflit o: for reducirig he — 
figure, as near as ay i to a regular one; i. ¢. ine 
lead of infcribing it in a circle, it fhould be infer ibed in 
an oval, fo that one half may be fimilar and equal to the 
Sie al 
s the irregularity of a figure depends on the quan- 
of angles and fides; the irregularity of a fortification 
artes either from the angles being tad 5 fmall, or the fides 
being too long, or too fhor 
Cia an ei figure being propofed to be 
fortified ; all the angles, with the quan sree . the fides, 
mutt be found, to be able to judge how it o be formed. 
See Plate V. Fortification fis 3. which a ie a for 
tification inf{cribed in an 
In this cafe vad fides Cc Dd, GH, on the flat parts, are 
ftronger than the fides A B, EF, on the narrow parts, 
fu uppofing all the exterior fides equal, and the place equally 
fortified. Whenthe angles B DE, of the polygon 
are very aa on the ping comes within a final dif. 
tance o » he cannot ne oach nearer, without 
“ox 
ye with trav erles 5 
extend their a 
fmall or large, the work of te poprecnes efore ie front 
DE will be to the work before the rae HABC, as 
the line B E is to the- line HC, nearly, 7. ¢, asthe greater 
N axia 
