Part 457

SIEGE, in the art of war, is to surround a fortified place with an army, and approach it by passages made in the ground, so as to be covered against the fire of the place.

The first operation of a siege is investing. The body of troops investing a town should, at least, be as strong again as the garrison: so as to be able to divide itself into several parties, in order to take possession of all the avenues leading to the place. By day they should keep themselves out of cannon shot: but as soon as it is dusk they must approach much nearer, the better to be able to support each other, and to straiten the town.

General phrases and terms used at a SIEGE are, viz.

To besiege a place. See SIEGE.

To accelerate the SIEGE, (Presser le Siege, Fr.) is when an army can approach so near the place as the covert-way, without breaking ground, under favor of some hollow roads, rising grounds, or cavities, and there begin their work.

An attack, is when the besieging army can approach the town so near as to take it, without making any considerable works.

To form the SIEGE, or lay siege to a place, (Mettre le Siege à une place, Fr.) there must be an army sufficient to furnish five or six reliefs for the trenches, pioneers, guards, convoys, escorts, &c. and artillery, with all the apparatus thereto belonging; magazines furnished with a sufficient quantity of all kinds of warlike stores; and a general hospital, with physicians, surgeons, medicines, &c.

To raise a SIEGE, (Lever le Siege, Fr.) is to give over the attack of a place, quit the works thrown up against it, and the posts formed about it. If there be no reason to fear a sally from the place, the siege may be raised in the day-time. The artillery and ammunition must have a strong rear guard, lest the besieged should attempt to charge the rear: if there be any fear of an enemy in front, this order must be altered discretionally, as safety and the nature of the country will admit.

To turn a SIEGE into a blockade, (Convertir le Siege en blocus, Fr.) is to give over the attack, and endeavor to take it by famine; for which purpose all the avenues, gates, and streams, leading into the place, are so well guarded, that no succor can get in to its relief.

To insult a work, to attack it in a sudden and unexpected manner, with small arms, or sword in hand.

Surprise, is the taking a place by stratagem or treason.

To escalade a place, is to approach it secretly, then to place ladders against the wall, or rampart, for the troops to mount and get into it that way.

To petard a place, is privately to approach the gate and fix a petard to it, so as to break it open for the troops to enter.

Line of circumvallation, is a kind of fortification, consisting of a parapet, or breast-work, and a ditch before it, to cover the besiegers against any attempt of the enemy in the field.

Line of countervallation, is a breast-work, with a ditch before it, to cover the besiegers against any sally from the garrison, in the same manner that the line of circumvallation serves to protect them in the field.

Lines, are works made to cover an army, so as to command a part of the country, with a breast-work and a ditch before it.

Retrenchment, a work made round the camp of an army, to cover it against any surprise.

Line of counter-approach, a trench which the besieged make from the covert-way to the right and left of the besiegers attacks, in order to scour their works. This line must be perfectly enfiladed from the covert-way and the half-moon, &c. that it may be of no service to the enemy, in case he gets possession of it.

Batteries at a siege, cannot be erected till the trench is advanced within reach of the cannon of the place; that is, within what is generally understood to be a point-blank range, which is reckoned about 300 toises, or 1800 feet.

Cannon is made use of at a siege for two different purposes; the first to drive away the enemy from their defences; and the second, to dismount their guns. To produce these two effects, the batteries should not be above the mean reach of cannon-shot from the place: therefore there is no possibility of constructing them, till the first parallel is formed; and as the distance of the first parallel from the second is generally 300 toises, the batteries must be on this line, or beyond it, nearer the town.

The construction of batteries belongs to the officers of the royal artillery, who generally consult with the engineer that has the direction of the siege, as well about their situation as about the number of their guns and mortars. They must be parallel to the works of the town which they are to batter. It is customary to place the mortar-batteries and gun-batteries side by side, and in the same line, to the end that they may batter the same parts. The use of both is to demolish the enemy’s works, to dismount their guns, to penetrate into their powder magazines, and to drive the besieged from their works and defences; as also to ruin and destroy the principal buildings, by setting fire to the town; and to fatigue and distress the inhabitants in such a manner, that they shall press the garrison to surrender.

To sally at a siege, is to go privately out of a besieged town, fall suddenly upon the besiegers, and destroy part of their works, spike their cannon, and do every other possible damage.

A sally, a secret movement which is made out of a besieged town or place, by a chosen body of troops, for the purpose of destroying an enemy’s out-works, &c. Sallies are seldom made when the garrison is weak; for although they molest the enemy, and keep him on the alert, yet the chance of losing men renders it prudent to keep within the works.

Saps in a siege, are trenches made under cover from the fire of the place, behind a mantlet or stuffed gabion: they are generally ten or twelve feet broad.--This work differs from the trenches, in as much as the latter are made uncovered. The sap has also less breadth; but when it is as wide as the trench, it bears the same name. There are various sorts of saps, viz.

Single sap, is that which is made on one side only, or, which is the same thing, has only one parapet.

Double Sap, has a parapet on each side, and is carried on wherever its two sides are seen from the place.

Flying sap, is that in which the besiegers do not give themselves the trouble of filling the gabions with earth: it is made where the workmen are not much exposed, and in order to accelerate the approaches.

Sap-faggots, are a kind of fascines, but only three feet long, and about six inches in diameter.