1000000030

R T

[1'

th:

f.me

cllnnrtl~,ion

be pelformcd on the other c,rles

el' the l'0lygun, you wllI hal'" the I'fIC'Llp,.1 ur outlinc of

lhe whole rurtílic.uun.

[f, wíth

ud",s

uf:o

toifes, thm be dtfcribed cir·

t ul.r arcs, froOl the anguldf pJIIltS

B, /I,M,T,

and línes

2re drawn f..om the oppolite angb

E, H,

OC.

1'0

as to

t.Oueh thefe ares, their part! ab, b, e,

&c.

to~ether

with

tbefe arcs will reprefem the (lutline of Ihe dlteh.

D EF IN ITIOSS .

l .

T he pan FEALN, is ealletl the b¡nion.

2 .

AE, AL, the faces of the banion.

EF,

LN,

the fi.nks.

4. FG, the eumin.

FN, the

gorg~

al' the baflíon.

AG, BF, the lines of dcCcnee.

' . AB, the exterior fide of the polygon.

8. CO,

the perpendicnlar.

Any linewhich divides awork i.nto twO equal pam,

i's

ealled the capital of that work.

10. abe, Ihe eounterfearpal' the diteh.

1! .

A,M, the fi.nked angles.

12. H,E, L, the angltS of the Ihoulder, or filOulder

ooly.

13. G,F,N, the angles of Ihe fi ank.

14 . Any angle whofe point turns from the place is

called a faliant angle, fueh as A, M; and any angle

whofe point turns towards the place, re.entering angle,

liteh as b, F,

there be drawD t\\'O liDes parallel to the priDci.

A T ION.

pal or outline, the one

toifes dinanc'., ami the OIJ,er

at S fromit; Ihen the f¡'.ee yx Indudcd btl" ccn the

pflnápjl

on~

aod

t1w

f.,rthdl dliljnt, is called the raOl.

polft.

,\ nd the fpace

xx ,

eomained by the princip,l line, and

thjt ntxt 10 it, and which is generally lIained black, "

eal lcd the parape\'

16. There is a fine line drawn wilhin four fcel of Ihe

parapet, which exprefi<s

nep called banquetle.

AII work, have a parapet of three loifes Ihiek,

and a rampen al' 8 tO10, belides thcir fiopcs. 'rhe

rampan is elevated more or lefs abol'e the Iml al' the

pl.ec,

from 1010 20

fe~I,

aecording to Ihe nature

01'

Ihe

ground and thc partícular conflrulllllns

englncers.

TIII: p3edpet is a part

01'

the rampan clcvaled from (,

fte!

abo\'~

the rtn, in arder tOcover the trOOrs

wlllch al e

dr.wn

up Ihere f'OI1l the

fire

of ¡he cnemy ID

a fiege; and the banquwe is t"O or Ihrce fm higher than

the rampart, or about fou r f<el lu",cr than the parapél;

that \Vhen the troops

fI.nu

upon il, they mayjufl be

able tO fi,e over the par.¡pel.

I7.

The body of the

pl.ce,

is all Ihat which is con·

tained within Ihis firl! rampan; for which mfon, it is

afIen faid

confiru(l the body of Ihe place; which

means properly, the eoufiruélion of Ihe

b~flions

and eur–

tains.

8. AII the IVolks w'hich are eon1rulled beyond Ihe

dileh befare the body of the

pla~e

are

called outworkl.

T A B L E.

Fans.

Liule f onif.

II~II ~I

Side

01'

1'01ffi:..._1

!...o~

110 120 13011

\ 160

~II ~

'YO II'~CO

Perpendlcul.

10 1I 12:

...:1

161 20

~5 1

;t¡ 25

Faces-baU.-\;;

\25\28

40 \ 4 2 '\ _:111_42//

\ 5311 55

\~I

ca¡;or;a~

. 25 .

2s .

JI .

8 .

40 45 . 50

\ 5

I 60

50.

the fi rn vertical eolumn are the numbm exprefling

lhe lenglhs of rhe exterior fides from 80 to 260.

In the fecond, Ihe perpendiculars anfwering tO Ihefe

fldes.

In lhe third, Ibe lengths of the faces of

b~nions;

and

io the founh, Ihe lenglhs of the

eapit.ls

of the ravelins.

Thc fansare monly, if not always, fquarcs; fur which

reafon, lhe pcrpendiculm are made one eighth of the ex·

terior fides; bmufe if they were more, Ihe gorges of

lhe banions would become tOO narrow.

The liule fonifieation is ehieAy defigned lar citadels,

~od

are eomOlonly p<ntagoos; the perpendiculars are

made one fcvemh of the exltrior fide; the mean is ufed

in all kinds of foniC,cations from an exagon upwards tO

~oy

r.umber al' fides: and the grcat is fcldom ufed bUI in

an irrcgul.r fortificalion, where therc are fome fides that

cannot be made lefs without mueh expenee: or in a tOlVn

whieh lies near a grw river, where the fide neXl Ihe ri·

~er

m.de

from 200 to 260 talfes; .nd

th:tt fide is

lefs expofed tObe au.¡cl ru than aoyother, the perpeodi.

1" is made OlOrlCr, wh"h faves much expence.

Tb ' f¡ces uf the blt:,ons

üfC

a11 ; ths al' Ih exterior

fides,

nearly fa, beclllfe Ihe fraeíons are neglelled.

may be obferved in general, thal in all fquares Ihe

perpendicular is tlh al' the

CKm

ior fide, aod

.11

peola–

gons ,th, and in all the refl upwarus ilh.

l .

C.njl,l/fli,,, 01

O,il/<III

and ,rliud

Flad/...

De(cribe Ihe fron l

~IPQ!~ST

:ISbefare, and diVIde

Ihe fi,mk into thrce equal pans, of \\'hich fuppofe Sr.10

beone: from Ihe oppofite fijnkeu angle M draw a "ne

MI',

in which lake the part mr

5 toifes; I¡ke ItkeIVlfe

Rn in the line 01' defence IR , produced, e9 u?1tOS

toifes, and jalO nOl, upon \\'hieh as a baf, ddcflbc Iht

equilaleral trionglé nplll,

~nd

fromIhe

ao~le

p, uppofite

tOIhe

b~fe

as centre, is defcliblJ th: cireul" fiank nOto

Aorl if Sr be blf,(led by the perprnuiculJr 1,

anJ

another be Cl c,ged upon the

f.ee

5T. al S; the loter'

fe(lion 2 of thefe IWO pcrpendiculm, \\ill be the cenlre

of Ihe are wh,dr forms the onllun.

The orillons are very ufeful in covering Ihe rellled

fiank" whieh cannol be fetn but ,\",lIly in the.

fro(,~;

ancl .s thefe oflllons are ruund, th<)' cannol be fa

deflroyed s Ihey \\'oulJ

b~,

¡r

t!tey

~lI

iJJy

othu

~UI C.

Ctr;