A military dictionary

by William Duane

Baron d’Espagnac, in consequence of the remarks which are made by Marshal Saxe, in his Reveries, has in his supplement to that work amply discussed the subject of fortification, and described the different means of attack and defence. We refer the inquisitive officer to those works. Before we conclude these interesting remarks upon an art, which is certainly equal to any invention that has employed the skill and ingenuity of man, we must observe that in all periods, productions on that head have been as numerous as the subject has hitherto proved inexhaustible. It must, however, be acknowleged with some regret, that the tendency of the greater part, if not of all, seems to be an indiscriminate and bold attack upon the works of the immortal Vauban. These writers censure the methods of that great engineer by proposing something of their own, which only differs in appearance, and which they think proper to call a superior system. Assertions, and promises to afford new lights upon the science of fortification, have always, in fact, been profusely given by authors of this description. Their labors, however, are only so far to be regarded and esteemed, in as much as their different systems tend to point out the necessary calculations which are required to shew the expence attending their construction, and to prove the effects they might produce. The memoirs upon perpendicular fortification, written by M. Montalembert engineer, will throw considerable light upon these observations.

With respect to the knowlege of fortification, it must be manifest to every thinking man, that from a chief magistrate, or head of a country, down to the lowest infantry officer, the acquirement of it is more or less indispensibly necessary.

A chief magistrate of a country, should be well versed in the science of fortification, in order to examine the plans that are laid before him, and to determine upon the execution of proposed projects.

A secretary of war should know it, in order to explain the nature of the plans when questioned by a superior power, to calculate the expences which will attend the construction of works, and to distinguish good ones from those which might be useless and expensive.

Every commandant of a town or fortified place, should be well acquainted with the subject, because it may fall to his peculiar share to construct works in cases of emergency, or to add to those already erected for the defence of the place entrusted to his care. He likewise ought, at all times, to be able to ascertain how far such a place is capable of holding out.

Every director of fortification should be master of it, in order to discriminate between what is proper, or what is defective, and make his report accordingly.

Every infantry officer, in a word, should be conversant in field fortification at least, if not acquainted with the general system. For without some knowlege of its branches, how will he, in cases of emergency, be capable of throwing up a temporary redoubt, of fortifying a spot of ground which he is ordered to maintain, or of securing a common outpost?

Field Fortifications, fortifications de campagne, Fr. consist in the art of fortifying, constructing, attacking, and defending all sorts of temporary field works during a campaign.

Although an engineer may be perfectly master of the different methods by which a town can be strengthened and secured by permanent works, he should not remain satisfied with that acquisition, but carefully direct his attention to the distribution of ground, for field fortification. He should be able to ascertain, with geometrical precision, all the relative divisions and corresponding points of any situation in which it might be judged expedient to construct that species of fortification which consists in intrenched lines, fortins, or small forts, and in redoubts of various denominations. The shape or figure of these works is exactly similar to those of the permanent kind. Ditches, ramparts, and parapets must be dug and thrown up, to secure the former, in the same manner as they are practised for the protection of the latter. They only differ in their measurement and proportions. Intrenched lines are made for the purpose of covering a camp from any sudden insult of the enemy, which should always, on this account, be pitched in the most advantageous manner; contiguous to and facing that quarter where it is probable the attack will be made, a ditch must be dug, having three toises at least in width and two in depth. This must be defended by a parapet en redans, or be occasionally flanked with small bastions, two toises thick, consisting of solid good earth well pressed together, covered and supported with fascines; having likewise banquettes behind them sufficiently high to conceal the soldiers’ tents. If water could be conveyed, or drawn into the ditch from any adjacent rivulet, or river, the security would be greater. When the lines of intrenchment are thrown up with an intention to maintain the ground any length of time, a covert-way must be made, which should be regularly fenced with palisades.

There is another species of field fortifications, which is resorted to in order to keep up a communication between two places; in which case great care must be taken to prevent the lines from being enfiladed in any quarter; and if they should be exposed in that manner, no time ought to be lost in strengthening the weak points by constructing redoubts, or small forts. The defence of these redoubts and forts must be entrusted to small arms and musquetry, but not to cannon, as the range of the latter is always too extensive to prevent an enemy’s close approaches to the lines of communication from their field works, or forts. Necessary drains must be made to let out the water that collects, as it would otherwise destroy the works, drown the sentries, and cut off all communication with the main body.