When the enemy approaches the covered way, and is en deavouring to construct his lodgement there, or to effect his passage over the fosse, the guns that have been pre served are to be opened upon him, and an unremitted fire kept up as long as they are fit for use.
Such works as have sustained much injury, are always to be repaired with all possible dispatch, and ordnance is to be planted behind them to be ready for use. If the ene my has taken possession of the covert way, it will be ne cessary first to spring the mines there, in order to throw him into confusion, and then to attack him and drive him back.
The defence of the fosse is the next most essential part ; but cannot be of long duration, for if the counterscarpe is lost, all is lost. Still, however, a gun, or several riflemen, will be of the greatest use to hinder the passage of the fosse ; and sallies also may be made if the ditch is dry. If the fosse be wet, fire-machines will be useful to set the fas cines of the enemy on fire ; and where the water can be let in and out at pleasure, the enemy may be harassed for a considerable time. Even when he thinks himself master of the fosse, his works may be destroyed by a sudden inun dation. The besieged always have great advantages when the enemy is among their works, as confusion is likely to take place. In such circumstances .too, a sally may be successfully made.
The defence of the outworks, after the enemy has made a breach, is either attempted on the top of the breach, or from the work in its re-entering angle. In the first ease, the enemy is to be attacked by small mines, artificial fire works, and rafters thrown down upon him, care being ta ken that not overcome all these impediments, and the sectr, ns, where otherwise a good defence might have been made. As soon as the enemy has taken an outwork, and begins to construct his lodgement there, a small gun, or some riflemen, are to molest him constantly. Mines are also to be sprung under his lodgement, or any work where he has constructed a lodgement, an attack be ing always made upon him after every explosion.
Should an outwork be countermined, and the enemy be gins a subterraneous war, he must be opposed as formerly directed.
If the enemy's well be discovered under a work, it may be filled, as we formerly observed, with poisonous smoke, and his miner be killed by grenades and shells thrown in the fosse, or by others hung before his well, and afterwards burst.
If, after the enemy has taken an outwork, he can be again dislodged, all endeavours must be used for that purpose ; and to effect this, the most probable appear to be, to make a sally after bursting a mine, and to destroy his communi cation over the fosse.
The defence of the rampart, so often neglected, though great labour is frequently used in constructing it, is the last part of the defence of a fortress. The assault here may be sustained, when a strong section is to be had, or when there is a retreat to a place, where the garrison may wait till a convention be concluded, or succours arrive. Sometimes, however, circumstances do not allow the gar rison to wait an assault, and, in this case, the commandant capitulates, either to save the lives of many, or to prevent the inhabitants from being plundered. When the defence of the rampart is resolved on, the same rules are to be ob served as in the defence of outworks.
Circumstances must determine whether the enemy is to be opposed in the bi each, or attacked from the section. The latter is to be preferred, unless there is every reason to believe that the former will prove successful. A sally at the time of the assault may sometimes be useful ; but is always in such circumstances to be undertaken with cau tion.
A fortress with a citadel may be defended as long as pos sible; and when the enemy has penetrated by an assault, and when every thing necessary has been sent into the cita del, the troops are to withdraw to it, taking care that the enemy does not enter along with them. Rather than run any risk of this, indeed, part of the garrison is to be shut out. If the commandant is at last convinced that the fortress must surrender, he orders the chamade to be beaten on the at tacked front, or he sends an officer to the enemy, to pro pose an armistice. If this be granted, he sends some intel ligent officers to the enemy to conclude a capitulation, or the capitulation may be concluded in the town, the enemy sending two or more officers, with proper powers and in structions for that purpose.