FORTIF 
Block-loufe, is a building eredted in the middle of a work 
to fhelter the garrifon, and efpecially the guard, from bad 
weather. 
Profile, is the delineation of the vertical fedlion of a 
work, indicating the dimenfions of the feveral parts 
which compofe it. 
Angies, are the two lines which meet each other in a 
point, and the point where they meet, is called the angu¬ 
lar point. 
A faliant angle is that wliofe angular point turns from 
the center of the work. 
A re entering angle. , is that whofe angular point turns 
towards the center of the work. 
The flanking angle is that which is formed by the flank 
and the line of defence. 
A flanked angle is a faliant angle, whofe legs are de¬ 
fended from the tire of the flanks. 
Maxims in Fortification. ^-From the nature and 
variable circumftances of military architecture, certain 
general rules, or maxims, have been drawn, and laid down, 
by d ifferent engineers. Thefe may iiveed be multiplied 
to any extent, but the principal of them are the follow¬ 
ing : viz. 
x. That the manner of fortifying (hould be accommo¬ 
dated to that of attacking. So that no one manner can 
be aflured always to hold, unlefs it be affured that the 
manner of belieging is incapable of being altered. Alfo, 
to judge of the perfection of a fortification, the method 
of belieging at the time when it was built mult be con- 
fidered. 
2. All the parts of a fortification fhould be equally 
ftrong on all Tides, where there is equal danger ; and they 
fhould be able to relid the mod powerful machines known 
to be ufed in befieging. 
3. A fortification fhould be fo contrived, as to be de¬ 
fended with the fewed men poflible : which conlidera- 
tion, when well attended to, enables a fortrefs to hold out 
for the greated length of time. 
4. If there fhould be feveral works within reach of one 
another, they mud be difpofed fo as to proteCf each other 
mutually by their fire, without a poflibility of receiving 
any injury from it. 
5. Such works as are intended to defend others, fhould 
not be at a greater didance than the arms, with which 
the latter are to be defended, can teach. The reach of 
mufket fhot is allowed to be from 120 to 150 toifes; but 
it is only at the former didance at mod, that the efteCt of 
the mufketry can be relied upon. 
6. The flanking angle, that is, the angle which the 
flank forms with the line of defence, mud always be 
either a right angle, or more open than a right on , but 
it fhould not be above one hundred degrees, or as little 
more as poflible. 
7. The flanking parts mud always be fufficiently fa¬ 
liant, in order that from within fide of the parapet you 
may batter the whole breadth of the ditch of the part 
that is flanked. 
8. An advanced ditch is never to be made that cannot 
be filled with water, unlefs it be clear and enfiladed in 
its whole extent, and in an angle able to proteCl it from 
the work which it covers, or which it encompaffes. 
9. The mod faliant parts, which by their nature are 
the weaked and the mod expofed, fhould, as much as 
poflible, be the bed defended, and at lead by the fire of 
two flanks, befides the front fire. 
10. The interior Ipace of all kinds of works fhould be 
fufficiently extenfive to contain the number of men ne- 
ceffary for their defence, and that they may be at eafe ; 
and this is to be mod caretully attended to when the gar¬ 
rifon is to dwell in the work. 
11. The extent of all manner of works, indiferimi- 
nately, mud be proportioned to the number of men who 
are to defend them. 
12. All the country around mud lie open to the de¬ 
fenders; fo that no hill or eminence mud be allowed, 
¥ol, VII. No. 452. 
CATION. 
behind which the er.emy might flielter hiirfelf from the 
guns of the fortification ; or from which he might annoy 
them with his own. Hence, the fortrefs is to command 
all the place round about; and confequently the out¬ 
works mud all be lower than the citadel or body of the 
place. Thefe are the general laws and views of fortifi¬ 
cation. As to the particular ones, or fuch as refpeR the 
feveral members or parts of the work, they are next to 
be confidered, 
CONSTRUCTION of LINES or RETRENCH¬ 
MENTS. 
A line, or intrcnchment, confifls of a bank of earth, and 
a ditch, and, when Amply confidered, is of two forts. 
Fird, Such as the trenches carried on in a fiege, where 
the bank is between the ditch and the enemy or town ; 
and here the earth is thrown up againd the town, becaufe 
the workmen are thereby better covered in carrying on 
thfe works. Secondly, Such as ferve to enclofe a town 
or camp, fecure a pafs, cover the entrance into a country, 
or other place, &c. in thefe the ditch is between the 
bank and the enemy. The firft fort is ufually called 
trenches or approaches : and the fecond is more llriftly 
called lines, both of which are condantly praRifed in 
field-fortification. 
The projeRing of lines greatly depends on the nature 
of the place, and the time that can be taken to condruft 
them ; thofe made at leifure being very different from 
thofe thrown up in hafle. A road or pafs may be advan- 
tageoufly held by few men againft a much greater num¬ 
ber, otherways than by throwing tip lines ; as by turning 
a water-courfe, planting dakes, felling trees, digging 
ditches, making a fence of dones, &c. But the mod de¬ 
fen live mode is certainly by a regular line of fortification. 
To throw up a Line across a Pass. —Having 
chofen the place mod convenient for the line, let a rope, 
or twided haybands, be run quite acrofs the way along 
the intended place of the line, pegged to the ground at 
every four or five yards; and at the didance of about 
twelve feet before the line, toward the enemy ; let fuch 
another line, or a row of dakes, be carried in a pofition 
parallel to the fird rope. Then range the labourers or 
troops within thofe limits, either fingle, in pairs, or treble, 
&c. according to their number, or the time in which the 
work is to be completed, each being furnifiied with proper 
tools. Let the earth, as they dig it up in this breadth, 
be throw n on the other fide of the fird rope, until a bank 
of about five or fix feet thick and fix or feven feet high 
be raifed ; obferving that the fides of (he ditch be doped, 
in the fame manner that the earth naturally rolls down 
the bank; and continue the digging till the ditch is 
about five or fix feet deep, the breadth of the bottom 
being about one-third of the breadth daked out at the. 
top. Let the inner fide of the bank be pared with the 
fpade into fuch a Hope, as a man danding upright may 
eafily touch, with his arm extended draight before him ; 
and at the foot of this bank let a foot-bank or dep be 
raifed, of fuch a height, that a man handing on it may 
eafily fire his mufket over the bank ; that is, let the top 
of the foot-bank be about four feet and a half lower than 
the top of the bank or breafl work. 
A work of this kind being completed, the troops be¬ 
hind the line may wait the coming of an enemy with lefs 
concern : For, 1 ft. The bank or bread-work fecures them 
from the enemy’s fire. 2d. When they dand on the foot- 
bank, they are more than two-thirds covered, while the 
enemy are wholly expofed ; and confequently the troops 
within may make three of their (hots tell for one of the 
enemy’s. 3d. They can, by going oft' the foot-bank, 
be quite covered while they load again. And on the 
whole, they are in no great danger of being forced from 
the lines while they have courage enough to defend them j 
except the enemy are greatly fuperior in numbers, and in 
artillery. 
The magnitude of lines is generally proportioned to 
7 M. the 
