The most advantageous period for surprising a fortress is in winter, during the long nights; and the best time of the night for effecting it is from two to three hours before daylight. The order for such a surprise is to be given, and the preparations are to be made, as secretly as possi ble, to prevent the enemy from obtaining any knowledge of it. The march of the troops to execute a surprise ought to be secret, that it may not raise any suspicion ; and it must be so calculated, that they may reach their respective places at the proper moment. In proportion to the dispatch and secrecy with which such a march is executed, will be the probability that such surprise will not be discovered ; and therefore a sufficient number of people to serve as guides should be ready, that nothing may be wanted, nor any detachment retarded in its opera tions from unforeseen accidents.
If a secret understanding with any of the garrison or the inhabitants can he procured, it will always be very ad vantageous ; but still it is far superior to gain a secret entrance into the place. It is impossible to lay down general rules for this part of the subject ; nor is it neces sary, as accident, and the circumstances of the moment, will instantly point out to the experienced commander the most proper mode. It may probably happen, that one part of the town is not well watched ; 7,t! l• this case soldiers may enter there, attack the ge . .;.,te, and open it for a small party, that has heel p • iv Close to it. \\Then this party enters, it i , • be followed directly by a larger force. Another metro, of penetrat ing a town is by approaching; secretly to the gate, and opening it by a petard ; but this is hardly possible in our times, fortresses being generally so well that it is impossible to approach their gates without being (Hs covered.
The gate of a town may sometimes be entered by mask ed soldiers, or soldiers who are habited in regimentals like those of the enemy, and who, under some pretence or other, attempt to be lct in by night. A similar ruse dr guerre might be practised, if the gates were opened too early in the morning. Masked soldiers might also enter a fortress as farmers ; and as soon as a sufficient number of them have penetrated, they might attack the guard, and keep one gate in their possession until reinforcements arrive. Soldiers, under the pretence of being deserters, may also sometimes get possession of a gate. A secret understanding with some person in the fortress may essen tially contribute to its surrender ; and also the sending into the place, unknown to the besieged, a small party of sol diers, who, at an appointed time, are to let in a larger force. Perhaps au officer of the garrison may favour an
attack, and thus a strong detachment will easily become master of a gate.
The soldiers who, after the surprise has succeeded, are to be employed in conquering the town, must have already received their orders where to march, and what service they have to perform. Detachments are to be sent di rectly to occupy all guards and guard-houses, as also all the places of rendezvous, the caserns, the magazines, and all the gates in particular, so as not to allow the enemy to collect any where, or to approach such places. The com mandant and all the chief officers are to be made prisoners as soon as possible, and every thing done that can contri bute to create confusion among the enemy.
On the instant that a surprise has succeeded, all the guards are taken by the assailants, and all such parts of the works as have been destroyed, or want repair, are im mediately to be put into a state of defence. If, however, a surprise does not succeed, then the retreat is to be ordered, and to be executed with as much regularity as possible ; and even in case of success, no soldier is to be allowed to quit his rank and file until all the fortress is completely in their power.
The ofien attack of a fortress, or the attack by an esca lade, is, in some respect, similar to a surprise, and an in tended surprise is often changed to an• open attack. An open attack can only be executed if the fosse of a for tress is easily passed, or if the water in it is not deeper than from four to five feet ; if the revetements are not more than twelve feet above the bottom of the fosse, and if the garrison is not always on the alert, so as to direct the fire of guns mounted on the flanks against the assail ants. Should there be no revetement stone to obstruct an escalade, other impediments may easily be cut off. Thorns, however, and bushes, are difficult to remove, and require a considerable time, if they are planted very thick. Ladders used to effect the escalade are to be con structed for the purpose, and should always be of such a length as may be necessary to mount to the top of the reveternent. If it be found requisite to use very long lad ders, two or more short ones, joined together, will answer the purpose, and will also be more easily taken loin one place to another.