inary way, 
silenced, and the fall of the place m 
out with shewing how the 
be retarded. This is pri to be done by 
lar sorties, so contrived, that the sallying force 
s be greater than the force to be attacked. 
ies commonly made in the t system of 
fence are too to be effectual. are . 
ways made at same points, where; 
the enemy is always prepared to receive so 
that, before they can succeed in destroying any of 
the works, they must combat a superior force. But 
by contriving to have a great number of points from 
which sorties can be e, the garrison may have fre- 
quent opportunities of attacking an inferior force, so as 
to insure success in destroying the works intended, 
without sustaining any considerable loss. By these, 
frequently repeated, the enemy’s p' is retarded, 
iseien are harassed, and he is bliged to employ a 
much greater number in defending his VERWE as it 
is only by a very strong guard at every ib int 
of stiack, that he can protect rs it ie ay 2 
the disastrous effects of pene pn $2 piiys should 
he beventen enasgh. 7. Fe cient 's on every 
part of his works, by crowding great numbers into one 
place, he only exposes them to a more certain destruc- 
snd vertical tion, from the immense number of vertical fires ( feux 
ares. verticaur), which form the second, and indeed the prin- 
cipal I parts of Carnot’s method of defence. These con- 
sist of mortars of different calibres, elevated at an angle 
of about 45 degrees behind the parapet, and covered M 
blindages. In this way, the guns themselves, as we 
as the men who work them, are completely protected, 
both from the direct and ricochet fire of the enemy. 
When used, they are loaded with a sufficient to 
carry the shot to such a height, as that, by its descent, 
to prove fatal to the 
the effect produced by 
follow ; he 
enemy 
gs 
tion. 
Commence- The vertical fires are supposed to commence only 
=f prog when the enemy opens his third parallel, as the distance 
ious to this would render their effects less certain, 
‘rom this period till the opening of the breaches, the 
ggg tye tes 
to be 100 yards from 
i e ravelin, 
of the exterior side of the polygon 360 
ld occupied by the besieging army will be 
nearly. 36,000 square yards ; but, in eetow to calealake 
on the, miatmum effect of the fire, call it 60,000 yards. - 
It is now. necessary to ascertain how much of this 
space is actually covered by the bodies of the men who 
act as labourers and of the besi works, The 
penis. of, Sse men is generally estimated at’ a. 
Nomber fourths aang tees, ath pogo being foun 
sontained in too weak for resisting the sallies of ieeoae Sup- 
what space, posing then that the garrison consists only of 4000, 
FORTIFICATION. 
the guard of the trenches will 
be 
$000 men will be spread over the surface of the ground 
occupying the avenues or passages, ; 
ofthe squere sochh, dae nied 
of one man to 20 square yards. sth -geteindenli 
Let itnow be su that a man’s 
horizontally covers one square 
thus be uired to cover completely a square 
But it has already been calculated that there is 
he 
: 
: 
; 
J 
a EFF 
g 
ry 
j 
E 
A 
a 
: 
as 
Bg 
Sn we ee dere 
so situated as to fire along the capital of each. 
mortars, as formerly observed, are 
45°. 
to prevent the collection of smoke, and 
with a small fossé to secure it from the shells 
fall near it. ' 
To estimate the effect of each piece 
pound, may be 
is, each mortar, at, a single shot, will discha 
600 such balls, being 3600 from the whole. But it has 
been shewn, that out of 180 balls, one may be supposed 
to strike the enemy ; therefore at each discharge of the 
six mortars, twenty of the besiegers.will be put hors de 
It remains now to inquire how many rounds may be 
fired in the of 24 hours, the fit beig continued 
during the night as well as the day. ‘These, ata mo- 
derate calculation, may be rated at 100, which allows 
nearly a quarter of an hour to each round. But at 
every discharge 20 of the besiegers are disabled ; there- 
fore 
; but these avenues, 
in 24 hours, 2000 men will be destroyed or rens- 
Number of 
rounds in 
one day. 
