1822.] Military Systems of Carnot and Douglas compared. 505 
conferred upon his name a high degree 
of celebrity. His profound mathema¬ 
tical knowledge, and the important use 
that Bonaparte made of his abili¬ 
ties, impressed professional men with a 
very exalted opinion of his system of 
fortification, and proposed plan of de¬ 
fence. Sir Howard Douglas, an officer 
of intelligence and scientific acquire¬ 
ments, has favoured the public with 
observations on Carnot’s plans of de¬ 
fence, and clearly demonstrated that 
vertical fire, upon which the French 
engineer relies with so much confidence, 
as the basis of the defence of a fortified 
place, is by no means entitled to any 
very great degree of estimation in re¬ 
pelling the at tack of besiegers.. 
Let us, first, bestow a few words on 
Carnot’s system of fortification and 
vertical fire , and afterwards examine 
the observations of the British engineer. 
1 n looking at the plan of Carnot’s for¬ 
tification, there seems to be very little 
deviation from the established rules of 
engineering, as laid down in the works 
of the celebrated Vauban. The rev£te- 
ment of his polygon consists of bastions 
and curtains, of saliant and re-entering 
angles—ditch and covert-ways, and 
the usual out-works found in the plans 
of that great engineer. In some minor 
particulars, Carnot has attempted to 
improve the defence of Vauban’s bas¬ 
tion, by a revfdement across the gorge ; 
but that is not a new improvement, as 
similar propositions have been suggested 
by several engineers. 
In the construction of out-works to 
cover the body of the place, there seems 
to be uo very material alteration pro¬ 
posed—the counter-guards, and demi¬ 
lunes, are not much improved; and the 
double covert-way, and additional re- 
vetement to protect the bastions, are 
little calculated to retard the approach 
of the besiegers. Indeed, M. Carnot 
seems to be sensible of the inutility of 
his out-works, as he appears to rely 
principally for the defence of his for¬ 
tress, upon vigorous sallies and conti¬ 
nued vertical fire. 
With regard to sallies, let it be 
observed, that a garrison must be very 
strong to defend extensive out-works, 
and to make numerous and determined 
sallies. Establishing extensive places 
of defence and garrisons of great nu¬ 
merical strength, is acting in direct 
contradiction to the acknowledged 
principles of fortification ; as the great 
intention in erecting a fortresses to en¬ 
able the state to hold an important po- 
Monthly Mag. No. 362. 
sifion wilh a small number of men* 
M. Carnot's fortified place is, tlierefore- 
in direct opposition to this fundamental 
principle, as his out-works are so ex* 
tensive as to require a strong body of 
troops for their defence; and the con¬ 
struction of the works is so inefficient 
as to demand constant and vigorous 
sallies, to repel the besiegers. With 
regard to the efficacy of sallies, profes¬ 
sional men are by no means agreed.. 
The most effectual one of modern times 
was that made by the garrison of Gi¬ 
braltar, under the direction of its vete¬ 
ran governor, the late Lord Heafhfield, 
when the whole of the Spanish batteries 
and approaches were taken and de¬ 
stroyed. 
The other branch of M. Carnot’s de¬ 
fence, vertical fire , Sir H. Douglas has, 
by the most satisfactory experiments, 
proved to be of no importance whatever, 
as precision in the direction, and effect of 
vertical projectiles, cannot be attained. 
The discharge of stones wmuld be use¬ 
less, and the operation of iron balls 
by no means so formidable as to impedo 
approaches of the assailants. The de¬ 
fence, therefore, of M. Carnot’s w r orks 
must still depend upon the usual arms 
and means employed in military war¬ 
fare. 
Having made these observations on 
M. Carnot’s fortification and plan of 
defence, let us enquire how it happens 
that so celebrated an engineer has nofc 
been able to devise a system of defence 
better calculated to resist ricochet and 
enfilading batteries ? Can there be no 
efficacious deviation from right lines 
and saliant angles , by which the artil¬ 
lery upon the works of the fortress may 
be protected ? Traverses are clumsy 
expedients, and occupy too great a por¬ 
tion of the ramparts—and could not 
such an engineer as Carnot prepare a 
better remedy ? It seems he has not—• 
and the only additional defence which 
he has adopted for his bastion is the 
casemated battery behind its gorge. 
This battery can only be mounted with 
mortars—-cannon would be useless, un¬ 
less the battery w as considerably eleva¬ 
ted above the guns upon the bastion, 
and in that case they would be exposed 
to the fire of the artillery of the be¬ 
siegers, who, from the nature of attack 
and defence, always possess a superi¬ 
ority of fire. 
Let us now turn to Sir H. Douglas, 
who has unquestionably shewn the best 
manlier in which M. Carnot’s fortifica- 
tion may be attacked and taken. But 
3 S there 
