The place where the fireworks are prepared, should not be far distant from this park, and the park must be as close as possible to that side where the attack, or where one of tho attacks, is to be made. Sometimes, however, it may be placed before a different front of the fortress from that which is to be attacked, in order the better to hide the in tention of the besiegers, or to take advantage of a more favourable part of the ground.
The stores of ammunition are to be dispersed in several places, in order that the whole of the powder may not be blown up by any single accident. The buildings erected for this purpose being generally made of wood, and cover ed by a mound of eartn, a ditch, and rows of palisadoes round them, are to be constructed at such places as arc covered from the enemy's fire. These houses for the re ception of the ammunition, or of the powder in particular, are to be made so as to keep the powder dry, and must consequently have a good roof, and some openings with shutters, which, in fine weather, may be opened for the free passage oLthe air. The powder is to be placed on boards, under which the air may pass free, and kept either in bar rels or in chests, in the same manner as ammunition chests on the carriages.
The depots for the materials are also constructed near the front where the attack is to be made, that they may easily be conveyed wherever they are wanted. Sometimes, however, to deceive the enemy, or for convenience, a part of the depot may be conveyed to another front ; but great caution is necessary on these occasions. It is not proper to place the whole of the materials in one depot, or too near storehouses, lest they should all be destroyed, and their destruction occasion damage to the storehouses also.
Sometimes palisadoes, and sometimes only a single ditch, is constructed round the depots ; and here, as well as round the powder magazines, sentinels are placed to keep all strangers or suspicious persons at a distance.
The tools and sand bags, or similar stores, may be kept at the depots of materials, but if possible under shelter, that wet, or other circumstances, may not injure them.
The choice of the front to be attacked, will principally be determined by the knowledge that has been procured from the surveys, the weakest being always the most as sailable. That side generally is considered to be the weak est which is commanded by eminences, or where the ram part can be hit at a great distance, where the terre-plein is very narrow, the bastions small, the construction or trace imperfect, the defence injudicious, the outworks weak, the covered way easily taken, the fosse small and not deep, the revetement damaged, or not of stones, where there are no mines, and where the besieger's works cannot be com manded.
With regard to the surrounding country, a dry plain and open ground sloping towards the fortress is most advan tageous. A stony soil particularly retards the siege, as also moorish ground. In these situations, the attack can only advance with a very small front, which is certainly very disadvantageous. hollow ways, hedges, walls, or similar objects, may serve also to cover the besiegers works. If a country be rather low, it is of consequence to know whether it can be inundated, which is a very serious disad vantage. The side of attack also, in some measure, de pends on the manner in which the ordnance and fascines can be transported. The follifications and their strength, however, generally determine the point, when the other circumstances are not very unfavourable.
The next thing to be considered is the plan of attack, which ought to be such, that all the works shall be con ducted regularly, and as few as possible constructed, so that the fortress may be taken in the shortest time. All this is the business of the officer who is to conduct the scige, and who is always present to direct and controul every thing on the side of attack. The works constructed by the be siegers as a defence from the fire of the fortress, are in general called trenches. Of these there are different kinds, as approaches, parallel batteries, and traverses.
Approaches are excavations about 3 feet deep, and 10 to 18 feet wide, the earth of which is thrown towards the ene my in order to cover them. The direction of these work-• is towards the place, but generally zigzag, so that they al ways approach the fortress in such a manner, that none of them can be enfiladed. They are represented A, A, A, Plate CCU X. Fig. 1. Parallels are also excavations, about 3 to 31 feet deep, and 20 to 30 feet wide, the earth of which is thrown towards the enemy. They are constructed paral lel to the front of attack, as B, ii, 13. Behind the parapets are made banquettes, for the soldiers to stand upon, as in other fortifications.