F. (continued 3)

The great method, according to Vauban, contains on its exterior side from 200 to 230, or 240 toises. This extent is not uniformly the same throughout all the sides of a place, but is confined to that side which lies along the banks of a river, where he uniformly erects considerable outworks.

Vauban made use of his second method in fortifying Béfort and Landau. On account of the bad local situation of Béfort, and the impossibility of fortifying it with common bastions that would not be exposed to an enfilade in almost every direction, in spite of the traverses or rechutes which might be made: he invented arched bastions that were bomb proof, which he called tours bastionnées, or towers with bastions. These arched bastions are covered by counter-guards, the height of whose parapet almost equals the elevation of the towers themselves. Although strictly speaking, both these places are irregularly fortified, nevertheless a method of regular defence may be established from the construction of their works.

Vauban’s third system grows out of the second, and for that reason it is called ordre renforcé, the reinforced order or method. It was adopted in the fortifications of New Brisac. Vauban left nothing untried to bring this system to perfection, and he had the ingenuity to execute his plan at a less expence, than it would otherwise have been effected, by means of half revetements which he threw up in the outward works called the dehors.

This system, however, (ingenious and unrivalled as it certainly is,) has not escaped the censure of some writers. It must nevertheless be acknowleged, that their remarks are either founded in envy, or that they proceed from ignorance.

There are other systems of fortification which have been proposed by the writers of other countries besides France. We shall give a brief detail of them, and leave the inquisitive to go more at length into the nature of their methods, by referring them to the different treatises.

The Italians have furnished several authors who have written variously on the subject of fortification. The method proposed by Sardis has been generally esteemed the best.

The Spaniards in their methods of fortifying, never adopt that which adds a second flank. The obtuse flanked angle is not looked upon by their best engineers as a defective system in fortification.

Both the Italians and the Spaniards speak frequently of the ordre renforcé, which was originally invented to lessen the number of bastions in a great town or fortified place, and to render consequently the line of defence equal to the range of musquetry.

The Chevalier St. Julien, a very able engineer, has published a method, by which, he asserts, that works may be constructed not only at a less expence than others require, but in a manner that must render his defence or attack more formidable. He has likewise invented a new method for the defence of small places, which is preferable to the first, although it is not without faults. According to his system, the reach of the musquet is taken from the centre of the curtain. To this end he directs, that a covert lodgment, 7 feet high, and 10 toises wide, be constructed from that spot to the gorge of the half moon or ravelin. Cannon is disposed along the faces, and a gallery is erected for the musquetry, which likewise serves as a passage to the ravelin.

Francis Marchi, a gentleman of Bologna, in his folio edition, has furnished us with upwards of 160 different methods of constructing fortifications.

The Dutch uniformly pursue the system published by Marollois.

Bombelle has likewise established three sorts of fortification, the great royal, grand royal; the mean; and the little royal, petit royal. His method agrees with the sound maxims of good fortification much more than any of the preceding ones.

Blondel has published a system of fortification, which he divides into two principal heads; the great, whose exterior side contains 200 toises; and the little, where the side does not exceed 170 toises. His reason is, because he objects to the line of defence having more than 140 toises, which is the furthest reach of musquetry, or less than 120 toises, to prevent an unnecessary increase of bastions. The principles of Blondel’s system resemble, in a great degree, those upon which Pagan’s is founded, and chiefly consist in methods of fortifying inward posts. The invention has certainly great merit, but its adoption must prove expensive in all its practical branches. It must, moreover, be manifest, that the four long batteries which are supported by flanks of his construction, must serve as so many scaling ladders, or steps to the besiegers, the instant they have effected a breach by cannon shot, or shells.

In 1689, a work was published, entitled:

Nouvelle maniere de fortifier les places, tirée de methodes du Chevalier de Ville, du Comte de Pagan, et de M. de Vauban; avec des remarques sur l’ordre renforcé, sur les desseins du Capitaine Marchy, et sur ceux de M. Blondel. This work is full of strong reasoning, from the result of which the author has formed a new method, containing indeed, nothing original, but giving references to what has already appeared, and disposing the different parts in so judicious a manner, as to shew how a place may be rendered stronger, and be subject at the same time to a less expence. This writer divides fortification into three parts, the great, the mean, and the little.

There is a second and a third method proposed anonymously, and containing mere simple designs. That method in which a modern author gives it the preference over the system of New Brisac, contains little useful information, and contributes less to the real art of fortifying places.

Donato Rosetti, a Canon belonging to Livournia, professor of mathematics in the academy at Piedmont, and mathematician to the Duke of Savoy, has written upon a method of constructing works in what he calls fortification à rebours, or fortification in reverse; so called not only because the re-entering angle of the counterscarp is opposite to the flanked angle; but because, in his idea, it will be necessary to attack it from the reverse side of other works. His system is very simple, and does not require a sacrifice of much money, or stand in need of many men to defend the works: although he can, on his side, pour as much fire upon the enemy, as could be furnished by more complicated methods.

Antonio de Herbart, major of artillery, in the Duke of Wurtemberg’s service, in 1735, published a treatise on fortifications with square angles, which he calls angular polygons.

Monsieur de Montalembert has lately endeavored to bring arches, which are so much condemned by the Chevalier de Ville, into repute. He treats the subject in a manner, and upon principles so similar to those proposed by Antonio de Herbart, that it is almost impossible to separate the two systems. M. de Montalembert asserts, that the science of fortification, (as it is established and taught at present) can only be valued by the public on account of its illusion. He looks upon the use of bastions, as the effect of prejudice; he rejects them wholly, and substitutes in their room, a front of angular tenailles, polygons with small wings, and angular polygons. The engineers of the present day assert with confidence, that the chief security to be derived in works that are supported by bastions, must depend upon cross and reverse firing directed against the enemy’s lodgments on the glacis. Large half-moons are made, not only for the purpose of covering the curtains and the flanks of bastions, but principally to obtain a reverse firing, which effectually prevents the enemy from maintaining his ground on the glacis of a bastion, before he has taken the two collateral half-moons.

M. Menno, Baron of Coehorn, who was general of artillery in the Dutch service, lieutenant-general of infantry, director-general of all the fortified places belonging to the united provinces, and governor of Flanders and all the fortresses that lay along the Scheldt, has been justly esteemed for his extensive knowlege in the art of fortifying places. He was cotemporary with Vauban. This intelligent and sagacious officer being thoroughly convinced, that, however expensively the rampart of a town may be constructed, it could not long sustain the shock of heavy ordnance, invented three different systems, by which he throws so many obstacles in the way of a besieging enemy, that although the place be not in reality rendered impregnable, it is nevertheless so far secured as to make its conquest a business of considerable hazard and expence. We must however acknowlege, that the three methods which have been pointed out by this Dutch general, can only suit places and grounds that are nearly on a level with the surface of the water; that is to say of 3, 4, or 5 feet; which circumstance plainly indicates, that his attention has been chiefly directed to the soil and ground of Holland; so that his instructions are peculiarly applicable to low and aquatic situations. There is much skill discovered in his manner of treating the subject, and considerable ingenuity in the treatise he has published, which certainly contains several improvements that are exclusively his own. It would be impossible to force a passage, or to penetrate into any of his works, without being exposed on all sides, to the fire of the besieged, who are under cover, and from whose discharge of ordnance and musquetry, it is scarcely possible for an assailing enemy to secure himself.

Scheiter, a German writer, describes two kinds of fortifications, the great or the superior, and the small or the inferior species. It has been erroneously and unjustly stated, that the celebrated Vauban only copied after Scheiter, at New Brisac.

Every man of the least knowlege or penetration must see, that the whole system of that illustrious engineer differs essentially from the author we have quoted.

The defects which are manifest in all these different systems shew the superiority which exists, to this day, in all the fortifications that have been constructed by Vauban.

An anonymous writer in the Sardinian service, proposes two new methods of fortification in a work entituled Science de la Guerre, which was published at Turin, in 1744. After having discussed, at considerable length, the art of fortification in general, its utility, the different sciences which must be acquired towards obtaining any degree of perfection in that art, the various systems in it, regular and irregular, and the construction of palisades, gates, mines, casemates, magazines, &c. &c. he concludes with this extraordinary sentence: “It is not my intention to propose any alteration in the general system, but merely to suggest, that the style be rendered more intelligible.” It must be noticed, that this Italian writer in his preface, frankly confesses his deficiency in the French language. We shall however pass over what he says relative to the approbation which his proposed systems, or rather his explanation of methods already known has met with from scientific men, and give his own observations concerning the improvements that might be made. His words are—

“The first method which I propose, consists of a new figure and position that should be given to exterior works in fortification. Having constructed the body of the place after Vauban’s manner, my next object is to erect counter guards with bastions at the head, and flanks upon the wings. I have been induced to adopt this species of work, in order to remedy the inconveniences and the dangers which invariably attend works erected at the foot of the glacis. These works contribute very little to the security of the place, and can only be defended by cannon, which eventually do more harm to the garrison than to the besieging enemy, since they serve as an epaulement to the battery, which the latter will naturally erect the instant he obtains footing in that quarter. This was proved during the siege of Turin, where in a very short space of time the French carried the bonnets and fleches, and made use of them for the purpose of bringing up their artillery.

By means of the small bastions which I have proposed, and which must be pushed forward into the country, the enemy’s approaches are necessarily checked, the saliant angle of the counter-guard is covered, the ditch is completely flanked, and the garrison are impressed with confidence, because the artillery and the troops can always be called in, in cases of exigency. They moreover equal the enemy in the fire which they can furnish, and the whole body of the place is covered by them.

I construct the bastions and flanks out of the sides of the counter-guard, which are detached by means of a ditch 4 toises wide. This ditch is covered above by vaults made of brick or timber, and by boards well supported underneath by strong stakes, the whole being strengthened and rendered bomb-proof with earth 3 or 4 feet thick. This earth keeps the upper plan of the bastion compact, and is sufficient to form a parapet to the counter-guard when the bastion is destroyed. If the vaults should be blown up by mines, and the besiegers set fire to the beams that supported them, a fresh work will present itself, together with a ditch which they had not foreseen or expected, and which they must cross before any further impression can be made.

This sort of subterraneous fortification is extremely advantageous, and may be converted to various purposes. It serves for casemates and galleries to the mines, which I would construct along the whole extent of the faces belonging to these bastions; a communication with them is kept up by means of the galleries attached to the counter-guard. These galleries must be blocked up the instant the bastion is demolished. The flanks of the side will be built after the same method, with a ditch as wide as the one dug in front of the bastion, and which, according to circumstances, may be uncovered, like that already described. The flanks will be of a round figure, in order to avoid the projection of any angles towards the body of the place, which would be the case, should the work be carried; for the enemy availing himself of the earth in front of the walls, and throwing it up, would derive considerable advantage from these angles.

The principal advantage to be obtained from my system arises out of the double defence which it affords to the saliant angles of the bastions, by covering a part of the demi-lunes mitrées, or mitred half-moons (which are their chief protection,) and by these means concealing the body of the place from any outward command, or eminence. This cover or defence cannot, in fact, be taken, before the enemy has got complete possession of the outworks.

I have spoken of these sorts of fortification in the chapter that treats of field works, which, in my humble opinion, are more useful, more solid, less expensive, and more easily built than a variety of others that have been adopted to this day.

The demi-lunes or half-moons which are nearly mitred or crossed, and which I dispose between the counter-guards, have been constructed in that manner for the purpose of stretching as far as possible, beyond the body of the place towards the country. One essential advantage attends this method, which is, that the work being more spacious, it is better calculated to hold a greater quantity of artillery, and a large garrison; that it becomes double by means of the ditch, which separates it from the advanced work, which it covered as described above, and which is joined to the interior revetement by plain walls, separating a whole half-moon from it; in which space a small fort with loop-holes may be constructed to enable the garrison to dispute every inch of ground as the enemy advances. Under the main body of the place, I build a subterraneous chamber, to serve as occasion may require, either for a powder magazine, or for mines.

Between the half-moons and counter-guards, I construct another kind of ravelins, which are open towards the body of the place, cover the curtains of the counter-guards, and supply a double fire against the enemy and the covert way. These ravelins are not raised so high as the other works, in order to keep them under their fire; and I preserve a communication by means of palisaded caponnieres. I leave them empty within, that the besiegers may have as little ground as possible; they are moreover sufficiently thick and solid to withstand the discharge of ordnance, which can only batter in breach from the counterscarp, which acquires double strength, because by means of these works, it is enfiladed, and secured against the enemy’s attack or attempt to make a lodgment.

If the plan, which I had the honor of laying before the king of Sardinia, be carefully examined, it must be apparent to every military man, that the works I therein describe, are not only more useful, but capable of being constructed at a less expence, than those which are generally practised to this day. It will be clearly seen, that I have done nothing more than add some additional proportions of the flanks and bastions to the counter-guards, which are usually erected; and that I have augmented their double face, by joining it to the half-moons of the curtain. The object of this addition, is to throw obstacles in the enemy’s way, should he attempt to make close approaches, to cover the body of the place, to render the siege difficult, to increase the besieger’s expence, and to give confidence to the troops of the garrison, who are thereby no longer exposed, as they must be in all outworks erected upon the foot of the glacis.

It is not, however, my design to throw works of this kind into utter disrepute. There are situations and local circumstances, which not only make their adoption useful, but render it absolutely necessary. I cannot pretend to describe the specific nature of such exigencies, as they grow out of existing cases, which an able general and an engineer will know how to discriminate by examining the ground.

The ditch belonging to the body of the place, be its soil what it may, must be very broad, as the chief security to be derived from it, depends entirely upon its width. The enemy cannot easily fill it up, and he must suffer a considerable loss of men, should he attempt to cross it; being exposed to the discharge of artillery from the flanks, which artillery cannot be dismounted from any quarter or lodgment, before the counter-guards are taken. The storming of the place must depend entirely upon the previous conquest of the side ravelins, and of the centre half moons; for unless the enemy has first effected this, he will not be able to cross the ditch, or make any lodgment, since at every approach he must be annoyed from the flanks, and battered in front; he must, in fact, attack and get the better of five works at once. The execution of any part of so important a task, must be the more dangerous, because in proportion, as he overcomes one line of defence, another presents itself which is equally formidable, and the rest increase in difficulty and hazard.

When I submitted this new method to the consideration of able and intelligent men, only one opponent started to controvert the property of its general adoption. This was a celebrated Dutch engineer, who asserted that it could not be of any essential service, except in hexagons, or figures that had many sides; he further argued, that the method was more faulty in small works, because the angles became more acute, and that no use could be made of them in regular fortification.

I had the good fortune to satisfy this gentleman, and to convince him, that his objections were not well founded. I stated to him, that by increasing the width of the ditch at the angle of the flanks of the bastion, I reduced that angle to any size I judged necessary; I maintained, that by so doing I did not weaken the place; but that on the contrary by cancelling the parallelogram of the counter-guards, I rendered more oblique any battery which the enemy might erect in front of the bastion, whilst the rampart belonging to it fell under a cross fire from the mitred half-moon.

With respect to its uselessness in irregular fortification, after having discussed the subject at some length, I got him to agree with me, that every detached piece of fortification might be constructed any where (and with greater advantage to the ultimate defence of a place) sooner than in plain counter-guards, horn or crownworks, tenailles and such like fortifications, because by means of the retreat which was secured under a second line of retrenchment, by means of the regular resistance it afforded, without having one dead angle attached, and by means of the little ground it left for the enemy to lodge on, the main body of the place was more effectually protected, and the approaches of the enemy were considerably checked.

With regard to the construction proposed in this new method, I take all the measurements, and I mark all the essential points upon capital lines; that is to say, I prolong the lines of the saliant angles of the bastion, and those of the centre of the curtain; after which I determine the width of the ditch at 23 or 24 toises, in order to make the parallels of the faces of the different bastions for the counterscarp of the counter-guards and of the great half-moon, and finally the thickness of the works, to agree with the ditches in front.

With regard to the ravelins which are made between the mitred half-moons and the counter-guards, I place the saliant angle in the centre of the scite, and I construct faces to them in such a manner, that they are under a straight line of defence from the half-moons and counter-guards. I erect the counterscarp and glacis in the usual manner, only with this difference that I wish to have a ditch of moderate breadth and depth between the covert-way and the glacis: say, two toises broad upon two deep.

In order to clear the ditch of occasional rubbish that may fall in, or of pieces that may drop from the demolished parts of a fortification during a siege, square excavations or wells must occasionally be made along the flanks and faces of the different works; by which means the ditch is always kept clean, and you may at any time repair the fortifications, whilst on the other hand, the enemy, should he attempt to storm the place, must have recourse to fascines, as he could derive no advantage from the materials that would otherwise be found under the walls.”

This ingenious writer has described every part of the method proposed in a clear and perspicuous manner. His plan is particularly valuable, on account of the exact measurements it contains, whereby the most common understanding may become acquainted with the construction. He appears singularly anxious to have it practically proved, that works can be erected according to this method at a less expence than by any other, and that there is no comparison between the advantages it affords in point of real utility. In chap. 16, p. 61, the following account is given of his second system, which he calls the Great System.

“After I had thoroughly digested my plan, relative to the best method of covering a town or fortified place by outworks, it naturally occurred, that I had not provided the necessary means of keeping the troops under shelter, of securing a retreat to the artillery, which is always seized whenever a work is taken by assault, nor of furnishing a heavier discharge of ordnance and musquetry than the enemy could pour in. These important objects put my invention to work, and I directed all the faculties of my mind towards discovering a kind of fortification which might not only cover the body of the place, and by a new disposition of its relative parts communicate equally with every quarter, without there being any necessity to carry the heavy ordnance into the ditch; but likewise oblige the besieging enemy to increase his means of attack, and make extraordinary efforts. I necessarily saw, that the saliant angles of the bastions should be well covered, and that the strongest ought to be raised before the curtain belonging to the body of the place, in order to force the assailants to make their attack on a quarter from whence the concentrated fire of several works, presenting a wide front of artillery, would issue with considerable effect.

After having for several years, directed the whole of my attention to this specific object, and tried the result of my reflections upon paper by a variety of designs; I had the good fortune to discover a method, whose plan exhibits to the eye several pieces that are joined together by their different walls, and in front of which there are ditches covered in with beams and strong oak boards, and made bombproof by means of a sufficient quantity of earth that is spread upon the whole. So that it appears evident to me, that there is only one species of fortification, which affords the means of concentrating your line of defence from every quarter, and of lining the parapets with heavy ordnance. By means of this construction, the lines and glacis will be secured against any immediate approaches of the enemy, during which seasonable interruption, the artillery may without risk, be withdrawn and lodged in the interior work; a convenience which cannot be obtained in detached pieces, on account of the difficulty which always attends the first erection, or ultimate demolition of them.

By taking away the beams, or by destroying them at once, and by pulling down the walls which compose the flanks, you suddenly open a new work upon the enemy; which work has the advantage of being considerably larger than the one he has just attacked and taken, and against which he must raise fresh batteries, and prepare the means of crossing a ditch, he had not foreseen, and which he cannot easily pass. This work either communicates with a tenaille that commands it, or is connected with a horned work, flanked by two others of similar construction. The tenaille is open in the centre (being divided into two parts by a ditch) in order to leave as little room as possible for the enemy to lodge on, and to multiply the enfilading points of the place.

Between these large works, demi-lunes or half-moons, of three orders, are constructed in the shape of bastions. These have orillons and ditches between the two, which flank the side-works, and are always protected by an enfilade, that the enemy never can lodge without being exposed to a cross and rear fire. In order to cover the whole body of the place, I construct other intermediate demi-lunes, which are equal in elevation to the first works. These contribute greatly towards preventing the enemy’s approaches; for they not only enfilade the covert-way, but they likewise double the defences in such a manner, that the enemy, as has already been observed, cannot attack one place without experiencing a necessity to attack four others at the same time: to which may be added this disheartening circumstance, that as fast as he advances, so fast a retreat is made behind some new work, and he is, of course, obliged to recommence his attack.

The regular communication between the several works must be kept up by means of sleeping bridges, which are well supported underneath by strong beams or stakes. Those which form a part of the rampart must be covered with four feet of earth, well pressed together. The walls by which the works are connected, must be so built as to be easily demolished, and they must only serve to cover the subterraneous fortifications. These walls are never within the reach of the enemy’s cannon, and when they are pulled down, their ruins are thrown into wells, or excavations, which have been previously dug at the foot of the main wall, to prevent the ditch from being filled with them: subterraneous embrasures are opened from within to enfilade the ditch, and to obstruct the passage.

When by dint of perseverance, and after having expended considerable sums of money, lost many lives and consumed much time the enemy has at last obtained possession of these works, he discovers, that his sacrifices have only led him to an unexpected body of the place which he cannot injure. This new construction he finds flanked on both sides by two double bastions, and a broad curtain lined with a triple front of artillery, having a very wide ditch, traversed by tenailles, batteries from casemates, and defended by flanks with the two cavaliers belonging to the bastions, which keep up an incessant fire upon the artillery that is planted in the carried outworks, and render it almost impossible for him to establish a lodgment.”

“I need not pretend,” continues the same author, “to have discovered by this new method, any certain means of rendering a place impregnable; such an idea would be chimerical and absurd.

Let a town be ever so well fortified, that town, if properly invested and resolutely attacked, must eventually fall, unless it be seasonably succoured from without. My chief object is to correct the errors into which former writers seem to have fallen, and by the methods I have proposed, to harrass a besieging army, not only by increasing its expence, but by occasioning a considerable loss of men; I thereby prolong the siege, and gain time for the garrison, so that succours may arrive, or such conditions be entered into as will secure the country, which the place attacked is destined to cover.

Counter-guards, ravelins, and demi-lunes are, in fact, a species of fortification by which they flank one another obliquely, and which only tend to embarrass the troops of the garrison, whenever it is judged expedient to manœuvre under the fire of artillery; a circumstance that invariably causes confusion; whereas the works which I have proposed are capacious enough to admit of every movement and evolution without inconvenience.

Horned and crowned works are extremely expensive in their construction, and of little use when completed; their lines of defence, their faces and their flanks are so short and limited, that a besieging enemy can with great ease attack, and carry them by means of an equal front and range of fire: and when he has so far succeeded, he derives considerable advantage from having opened a wide space of ground on which he can erect angles to annoy and batter the place. Whereas in the works of my proposed method, the foundations are broader, the defences are more direct and within musquet shot, and when the garrison retreats towards the body of the place, the ground which it abandons is scarcely sufficient for the erection of a small battery; it is moreover exposed to all the retrenched and flanking points, so that the enemy would be instantly dislodged.

Tenailles and queues d’hirondelle contain dead angles which may always be taken advantage of by the besieging enemy. This does not exist in the works I propose. For at every approach, not only fresh expences must be incurred by the assailant, but he will remain exposed to several fires at once, without being able to cover himself from the reverse and cross ones.

Double ditches afford the means of creating perpetual uneasiness in the enemy, by uncovering fresh works as he advances. So that the siege is protracted, his expences are increased, and his loss of men, ammunition, stores, and artillery is proportionably multiplied.

In the examination which was made of the relief proposed by me; some persons well acquainted with the particular subject, objected to its adoption on account of the expence. I made an accurate calculation of the amount, and I found that it cost a sixth more than the usual fortification. This does not assuredly form sufficient ground to outbalance the many advantages which can be derived from the construction. Besides, there is no occasion of fortifying all the parts of a town in this manner, since it would be advisable to strengthen the weak points only.”

The construction which is proposed in this new method, is simple, and easily understood. The principal objects to be attended to are these; that there be mines under all the works, and that a regular communication be kept up with the chambers by means of subterraneous galleries, which must be resorted to in proportion as the enemy approaches.

The Piedmontese engineer, from whom we have made these extracts, has added to Vauban’s and Coehorn’s systems. We leave the subject to the consideration of those professional men who have made the art of fortification their peculiar study; they must determine whether the theory of the proposed method be susceptible of practice, and if so, whether it can be rendered so generally useful, as the author seems to promise it would.

On a general view of the subject it must, however, be acknowleged, that a situation is not always found which will admit of the improvements and additions that might otherwise be made. There are some old places in which the figure of the fortifications erected for their defence, is so strange and whimsical, that the least correction of its errors, must be attended with an enormous expence.

A town may be irregularly fortified, and owe that irregularity either to the figure of the works only, by the angles not being equally distant from the centre, although every one may admit of a good bastion, and the lines be tolerably extensive; or by the figure and the angles differing, from some being too acute, and others being rentrant; or by the inequality of the figure and its sides; some being too long and others too short; or finally by a disparity all together in the figure, in its sides and angles.

If the three first kinds of irregularity are judiciously corrected, the correction of the fourth follows of course, as it is only the natural consequence of the others. Those irregularities may be occasioned by a neighboring river, by the entrance into a creek or harbor, or by steep rocks beyond which it is impossible to carry the works.

It is a sound and general maxim in the art of fortifying, to reduce the irregular proportions of its lines, &c. of defence to as much regularity as the ground and situation will permit. For by so doing, their strength becomes equally great throughout. If you should not be able to surmount the natural obstacle which may be thrown in your way, you must never deviate from the general rules that are laid down in regular fortification. These are, that all the parts be well flanked, that the angles of the bastions do not fall under sixty degrees, that the line of defence be within musquet shot, or that outworks be established to bring it within that range; and finally, that the means of resistance be distributed in as many equal proportions as the irregularity of the works will suffer.

You must, however, be careful to avoid an error into which many have fallen. You must not weaken the collective means of defence, in order to strengthen any particular vulnerable quarter; for by so doing you are sacrificing a great line of defence, to the security of a small part which might be strengthened by outworks.

The author of Oeuvres Militaires, in his 3d volume, page 45, has given observations and maxims relative to irregular fortification.

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.

When a position is taken upon a steep rock, or eminence extremely difficult of access, the lines which surround it do not absolutely require ditches for their safety, as the parapet and banquette may probably be sufficient; but if any vulnerable or weak part be observed, every effort should be used to get at a spring, and to fill up an excavation in front of it, to prevent surprises. An able engineer will be particularly careful in drawing his plan of communication, to ascertain the exact points whereby they may be protected by an enfilade from one fort to another; so that if the enemy should make a lodgment any where, he will not be able to maintain his position on account of his being flanked by other works.

Field works, or small forts are generally constructed in places the preservation of which is judged to be indispensibly necessary. Such, for instance, are necks of land that stretch into a marsh, and are surrounded by it; the passage of a road, têtes de ponts, or heads of bridges, and other objects of similar importance in offensive, or defensive operations. On these occasions the shape and size of the construction must depend upon the nature of the ground, the importance of the undertaking, and on the number of men by which the works are to be garrisoned.

Many forts in field fortification are built in triangular forms; some are square, some starred, or en étoile, some as redoubts, in the shape of demi-lunes, others in crown, or horn-work, and others again in the figures of tenailles or queues d’hirondelle.

When the object of defence is a windmill, a castle, or a small dwelling-house, the first step to be taken, is to select a spot of ground upon which you are to build the field work, so as to check and prevent the enemy’s approaches. In order to do this effectually, the shape and adjacent parts of the building must be closely attended to, and the work be thrown up without exposing it to a rear attack; but if the place to be defended stand alone, and be not supported by any ditch or eminence on its flanks, or in its rear, you must then fortify it all round. The earth which is dug out of the ditch will serve to raise the rampart, or parapet. Saliant angles, distributed at equal distances, in the shape of bastions, must be erected with good flanks to protect and cover the intrenchment. If, on account of the ground, the work should not be much raised, the parapet must be raised, in order to prevent the enemy from attempting an easy assault.

An engineer from Piedmont, who has proposed some new methods in field fortification, is decidedly against stone and masonry, in the construction of parapets and field works. His reason is self-evident; for as he justly observes, the scattered pieces which must naturally be thrown about in all directions by the demolishing of the walls in the discharge of heavy cannon, would do more mischief than the cannon itself.

It is frequently found necessary to fortify a bridge; the means adopted for this purpose must depend entirely upon the size and current of the river. If the stream should be broad and navigable, and so far from the fortress, that it cannot be defended by the ordinance of the town or fortified place, in that case a large retrenchment, resembling a place of arms, must be constructed, with strong bastions to support and cover it, curtains and half-moons, a broad and deep ditch, and covert-way that must be well secured by palisades. This retrenchment, or place of arms, must be made sufficiently capacious to hold a garrison that would be capable of opposing the attack of a large detachment from the main army of an enemy. A half-moon must be constructed within the lines, with a ditch in front, to serve as a work behind which the garrison might retreat with its artillery, disputing every inch of ground, and by that means affording sufficient time to cut down the bridge.

If the river should be narrow, yet wide enough to prevent any sudden irruption into the country beyond it, the bridges that are across must be fortified by works made of earth, which are to be covered by ditches dug in front. Half-moons, tenailles, crown and horn-works, and similar constructions, provided they be well fenced with palisades, will answer all the purposes required in such cases. The engineer, by the first glance of his eye, will be able to ascertain the situation of the country, and to fit his plans accordingly. Small lodgments, or wooden recesses, must be made as guard-houses, in which detached parties of men should be stationed to meet the first attacks of the enemy, and to keep him in check while the whole army passes over the river, or is drawn up in order of battle to dispute the passage. These intrenchments must invariably be well furnished with light artillery, for the purpose of annoying the approaching enemy. But the disposition and arrangement of these pieces must always be such as to admit of their being instantly removed, when the intrenchments are carried, under the cover of heavier ordnance which is kept playing upon the enemy from the opposite side of the river.

Practical Maxims in building Field Works. 1st. The spot on which works are to be constructed should determine their figure; nor should any attention be paid to preserve a regular form which does not occupy the ground to advantage.

2d. Every line must be so disposed, that the slope of hills all around even to the very bottom, be open to the small arms of the garrison; and every part should be discoverable to the distance of at least 500 paces.

3d. Works thrown up for the defence of a defile, should always be within musquet shot of it, which must not be more than 200 yards.

4th. The best defence in works that are flanked, or where one side is defended by the fire of another, is that formed by right angles.

5th. A saliant angle should never be less than 60, and a re-entering angle than 90 degrees; nor greater than 120 degrees.

6th. The entrance to the work should always be made in the part least exposed to attack, and if possible in a re-entering angle.

7th. Endeavor to present, if possible, a larger front to the enemy than he can occupy in making the attack.

8th. Avoid all ground commanded by an eminence, either in front, flank, or rear.

9th. Never leave the rear of a work so exposed that the enemy may turn it.

10th. Always make the angles of a work in the directions least exposed to attacks, and consequently always present a front to the most exposed.

11th. The garrison should never be drawn up more than two deep; and an ordinary pace of two feet is usually allowed for each file, and from 6 to 8 paces from each piece of ordnance.

12th. If a work is so large as to be defended by a battalion or two, a reserve should be allowed of about one sixth of the number.

13th. The space within a work should always be sufficient for the men to move and lie down. Every soldier will require at least 18 square feet, and every field gun at least 216 square feet.

14th. Provided the line is not made too extensive, the more inward space there is the better.

15th. A parapet to resist cannon shot should never be less than 12 feet thick; and for musquet shot not less than 6 feet.

16th. The height of the parapet must be regulated by the situation of the work, and of the adjoining ground; with this consideration, that its height above the banquette does not exceed 4¹⁄₂ feet.

17th. The depth and breadth of the ditch must be regulated by the quantity of earth required for the parapet and banquette.

18th. A tête de pont, or work to cover the embarkation of troops, or the passage of a river, should, if possible, be made where the line of the river or coast forms a kind of re-entering angle; that the flanks of the corps, as well as those of the works, may be covered.

To carry on the work.—The number of workmen must be proportioned to the time allotted for carrying on the work, the quantity of labor, and the number of hands capable of being employed at the same time. When the ditches are broad, the workmen may be posted in two rows; but if narrow, only in one. In the first case, the earth will be thrown by those who are on the outward edge of the ditch to the second row, and by them upon the parapet; for which reason the second row, to keep pace with the first, ought to be twice as numerous. The workmen should never be placed nearer than 2 paces, or 4 feet, from each other; and two men with shovels should be preceded by one with a pickaxe. If more than usual expedition be required, one man with a wheelbarrow, or basket, may be added to six or eight with shovels. Another row of workmen should also be placed upon the parapet, to spread the earth and beat it down, as it is thrown up.

In fixing the fascines, three men will be sufficient for every 24 feet of the work, who should be provided with mallets, a saw, and a handbil, or hatchet.

In order to form some idea of the time in which a field work may be completed, compute the number of cubic feet of earth to be excavated, thus; multiply half the sum of the breadth of the ditch at top and at bottom, by the depth, for the number of square feet in the profile; and this multiplied by the distance between the workmen in feet will give the number of cubic feet each man has to dig: or being multiplied by the length of the ditch, gives the cubic contents of the ditch. Now one man is supposed to be able to move 216 cubic feet of earth in a day, during the summer; but this is not always the case. If a field work be completed in 24 hours, it will be as much as the most diligent workmen are capable of. This time is generally allowed for the formation of a weak profile; 48 hours for that of a stronger, with a revetement of fascines; and 72 for the strongest.

The different slopes for the works must depend upon the nature of the soil, and the materials of which the work is composed. The interior slope of the parapet, though it be fascined, should be ¹⁄₆ of its height; exterior about ²⁄₃ its height. The slope of the banquette equal to its height. The slope of the scarp or counterscarp of the ditch, should be from half its height to its full height, according to the soil. The superior slope of the parapets must entirely depend upon the situation of the work, and that of the surrounding country. The interior slope of the parapet is generally lined with fascines, to keep up the earth; but it is not absolutely necessary to fascine the exterior slope, if the soil be pretty stiff. The embrasures are generally made 20 inches wide on the inside, and 9 feet on the outside; they must always be lined with something to retain the earth; turf is generally preferred, as fascines are so apt to take fire.

The manner of making the materials for field works, may be seen under the heads Fascines, Gabions, Hurdles, &c. and the manner of estimating the quantity of materials for works of this kind, may be seen under the word Battery. See Am. Mil. Lib.

Fortification....Permanent.

A parapet, to resist cannon should never be less than 18 feet thick in earth, and 8 or 9 in masonry. A wall need only be two feet thick in masonry to resist musquetry. The parapet should always be 4¹⁄₂ feet above the banquette, and 7¹⁄₂ or 8 feet above the rampart, or terre-plein.

The Rampart should always be sufficiently wide to allow for the platform, and for two carriages passing each other; about 9 fathoms at top. A parapet of earth, though it takes more room, is always preferable to one of masonry, when it can be raised; though the only objection to the masonry, is the number of splinters it produces.

Entire Revetements of masonry are not advantageous for the same reason. The masonry of revetments should not be so high as to be seen or battered from a distance; earth parapets are battered in vain, as the earth forms a natural slope.

The best Scarp is made of masonry, either in wet or dry ditches, be the earthen one ever so well fraized or palisaded. The earthen one may be stormed without making a breach. The scarp should be 30 or 35 feet high.

The Counterscarp should also be of masonry, and not less than 12 feet high. The inconveniences of an earth or low counterscarp, are the impossibility of defending to the last the covert way; as the enemy may descend into the ditch, and again mount the covert way, and so get in the rear of the traverses. The enemy may find his way along the natural slope of an earth counterscarp, and is not delayed by a tedious operation of getting into the ditch. Besides the natural slope of the end of an earth traverse prevents its effectually covering the covert way.

Ditches are generally 15 or 18 toises wide. Dry ditches are always preferable to wet ones, on account of the shelter they afford the troops, and the ready communication with the outworks, without the constant trouble and danger of bridges.

The Covert way should be 5 toises wide; less would croud the troops, and more would allow room for the enemy to erect batteries in it.

The whole of the glacis should be seen, not only from the crest of the parapet, but from the embrasures in the parapet.

The Tenaille, must not be so high as to prevent the flank guns in one bastion seeing the breach that may be made in the collateral one.

Ravelins are best without flanks; their faces directed to 10 toises from the shoulders of the bastions.

The crest of the parapet of the body of the place should be 8 feet above the crest of the glacis, to command it across a ditch of 15 or 20 toises.

The crest of the parapet of the ravelin is 3 feet lower than that of the body of the place, in order that it may be more effectually commanded from the place; and therefore to enable the parapet of the ravelin to command its own glacis, the ditch is only made 10 toises, and this glacis is a foot lower than that of the body of the place.

There must be an equilibrium of defence established through every front of a fortified place; for it will be needless to strengthen any particular front, if the others from their weakness be left exposed. The following remarks may enable an observer to appreciate the value of particular works, in the proper application and arrangement of which that equilibrium consists.

Intrenchments within the works add much to their defence. In large bastions with obtuse flanked angles, the best intrenchment is formed of the front of a fortification, or of two demi-bastions and a curtain, connecting the angles formed by the flank and curtain. If this intrenchment be advanced to the shoulders of the bastion, so as to include its flanks, as is often the case, it will be subject to be taken in the rear, by the fire from the counter batteries opposed to the flanks. But in bastions with acute flanked angles which do not afford sufficient space for this kind of intrenchment, Cormontaigne proposes one in the form of a cavalier, whose faces and flanks are parallel to those of the bastion. The first kind of intrenchment does not operate in the defence of the place, till after the passage of the ditch; till which time it remains entire, and then capable of a very great defence. The second kind becomes a support to the bastion from the first commencement of the siege; but it is therefore subject to have its defence destroyed at a distance. Nor is its defence equal to that of the other form.

Counterguards should possess the three following properties: 1st. They must cover effectually the principal work before which they are placed; at least that part of it, which can be battered in breach. 2d. They must be lower than the work which they cover; but not so low as to permit its revetement to be seen. 3d. They must be so narrow as not to afford room for the besiegers to erect batteries in them, against the work which they cover, and therefore not leave the besiegers a choice of positions. The counterguards in Coehorn’s system are only of earth, through which it is necessary to make an opening, before the capital work can be battered.

Horn or Crown works, unless to occupy some important point, to strengthen some weak side, or to afford more room for a confined garrison are rather a weak than a strong arm to a place. This is particularly the case when they are constructed with smaller, and consequently weaker fronts, than that part of the body of the place which they cover: as they facilitate, when taken, the approaches to the body of the place. This is remedied by constructing their fronts of the same strength as the front or fronts which they cover. They also facilitate the taking of the place, by exposing the revetement of the work on which their branches are directed to be battered in breach, along the ditches of those branches. This is a great evil, even to an outwork, but is of serious consequence if they rest upon the body of the place. This defect has been remedied by placing these works altogether outside of the covert way, and allowing their ditch no communication with those in the rear. In this case their gorge must be made very secure to prevent its being turned.

An Advanced Covert way, is esteemed amongst the best means of adding to the defence of places. Besides the advantages common to the usual covert way, it has many peculiar to itself. It however seems necessary to ensure to it the many advantages of which it is susceptible, (beside being properly palisaded,) that it should be secured in the rear by a wet ditch, as the only means of giving it an inaccessible counterscarp, and at the same time keeping it under the fire of the musquetry of the place. This kind of covert way is generally supported by redoubts upon the capitals of the bastions and ravelins which from their position cannot mask the fire of the place; and being mounted with artillery, oblige the besiegers to commence their attack at a great distance, and very much to extend their operations; and as their establishment upon this covert way must effectually mask the fire of their first batteries, it must greatly increase their labor. The retreat from these redoubts must be secured by an underground passage.

Countermines are undoubtedly one of the first means of strengthening places. For this article we refer to the word Mines.

Detached redoubts, when circumstances of situation favor them, are employed with great success. They are usually detached and totally unconnected with any of the works of the place, by any covert way or other above ground work; and have for objects, either the opposing an additional obstacle to the besiegers at the point they occupy, or the rendering the adjoining fronts inaccessible, by an enfilade or reverse fire upon the approaches. They also afford at their gorge, a most excellent rendezvous and retreat for sorties; upon the level of the country, and without the difficulty of filing troops through the barrier of a covert way.

But in order to insure to the detached work or works, all these advantages, it is necessary that they should be either totally inaccessible to the besiegers, by reason of the natural difficulties of their situation, as in an inundation, morass, &c. or be made secure by art, from being taken by storm, and only attackable by regular approaches. They should be under cover of the fire of the place; but if their distance be too great for that, an intermediate work must be established to give them support. Their best form is that of a bastion with retired flanks; and a strong system of countermines the most effectual way of prolonging their resistance.

General remarks...The larger the flanked angles of works, the more direct will be their fire, and that of their covert way, upon the approaches; the greater extent will they oblige the besiegers to occupy in their parallels and batteries; and the more will they oblige the besiegers to expose themselves to the fire of the fronts collateral to the one attacked. Faces of works directed to inaccessible situations, such as rivers, lakes, &c. from whence they cannot be enfiladed by ricochet batteries, add greatly to the strength of a front.

If the flanked angle of a ravelin be so advanced as to see in reverse any battery erected upon the crest of the glacis, or in the covert way of the bastions, it will increase the strength of that front; because it will oblige the besiegers to gain possession of the ravelin, before they can make any lodgment, from which they can batter the bastions. This is the case in Cormontaigne’s system: and a place thus fortified, obliges the besiegers to attack and gain two ravelins to get at the bastion between them. Beside, if this system be applied to a right line, or to a polygon of many sides, the prolongations of the faces of the bastions will be intercepted by the flanked angle of the ravelins, and consequently make the establishment of enfilading batteries against them very difficult. A work which admits of a breach being made in it (particularly the body of the place) at a distance, very much facilitates its being taken. The ditch of the ravelin affords an opening through which the besiegers may make a breach in the face of the bastion from the glacis, opposite the flanked angle of the ravelin, and is therefore subject to this defect. A counterguard before the bastion, lessens this evil, by transferring the breach from the body of the place to the ravelin; but it requires a counterguard also before the ravelin, effectually to cure it. A crown or horn work also produces this evil; its remedy was given, in speaking of those works.

The direction of the flanks or faces of a work is not so material as relating to the fire of artillery, as to that of musquetry; for artillery is never fired without being pointed, but musquetry is fired mechanically, and perpendicular to the parapet, without much attention to the object to be struck.

A work in the neighborhood of a height must be defiladed[8] from that height, that is, instead of being built upon a horizontal plane, it must be erected upon an imaginary inclined plane, passing from somewhere in the interior of that work, over the most commanding points of the height: and every part of the works must bear the same relation to this inclined plane, that they would do, to a horizontal plane in a level country.

A work is not therefore always to be condemned, because it is in the neighborhood of a height; for if it be properly defiladed from that height, it will receive a great advantage over the approaches of the besiegers, carried on down an inclined plane towards it. But a work to be properly constructed in the neighborhood of heights, must not uniformly preserve the same distance from those heights, unless their summits be all upon the same level; but must approach them at their lowest parts, and recede from them as they rise; thus will the necessary plane of defilement preserve nearly the same degree of obliquity throughout.

Dimensions of Walls and their Counterforts, from 10 to 50 Feet high, having a Slope of ¹⁄₅ their Height.

Wall. Counterforts.

Height. Thickness at Top. Thickness at Bottom. Distance between them. Breadth. Length.

Ft. Ft. In. Ft. In. Feet Ft. In. Ft. In.

10 4 0 6 0 8 2 8 4 —

15 4 3 7 3 10 3 4 5 —

20 4 6 8 6 12 4 0 6 —

25 4 9 9 9 14 4 8 7 —

30 5 0 11 0 16 5 4 8 —

35 5 3 12 3 18 6 0 9 —

40 5 6 13 6 20 6 8 10 —

45 5 9 14 9 22 7 4 11 —

50 6 0 16 0 24 8 0 12 —

The heights in the above table are taken only from the bottom of the ditch, and do not include the foundations.

When the rampart is partly walled and partly turfed; then ¹⁄₅ of the height of the turfed part must be added to the breadth of the wall at the top given in the table.

The bases of all inward slopes of earth should be equal to their height, if not more.

The bases of all outward slopes of earth ²⁄₃ of their height.

The superior slopes of all parapets ¹⁄₆ of their breadth.

The slope of all walls, or revetements ¹⁄₅ of their height.

Though the above principles given for the erection of field works may assist an officer’s recollection who may be employed on that duty, the memorandums given respecting permanent fortification pretend to no such object: but may serve to remind an officer, if he should visit a fortification, of its essential requisites; and may assist his observations in passing round the works.

FORTIN, FORTLETT, or FORTILAGE. See Field-Fort.

FORTRESS, any place strongly fortified.

FORWARD, a word of command, which is given when a regiment, or company has been interrupted in its regular movement, and the march is continued. On this occasion every succeeding division must preserve its proper distance and mark time until the word Forward, is given. This frequently occurs in the passage of obstacles, and in the winding of roads, streets, &c.,

Right or Left -

shoulders Forward, an absurd word of command, used in the British exercise. It is a gross misconception of the French line of science, which requires the whole body to face in the given inclination; every man must see that it is impossible for a soldier to march either with ease or grace in such a position. See Line of Science.

FOSSE, in fortification. See Ditch.

Fosses pleins d’eau, Fr. Wet Ditches. See Fortification.

Fosses secs, Fr. Dry ditches.

Fosses revétus, Fr. Ditches that are lined.

Fosses non revétus, Fr. Ditches that are not lined.

FOUCADE, FOUGADE, a small mine.

FOUGASS, in mining, a small mine, from 6 to 8 feet under ground: It is generally placed under the glacis or dry ditches.

FOUGETTE. Fr. Indian sky-rocket, a species of fire-work which is frequently used by the Asiatics. The author of a late military production in France makes the following observations relative to advantages which might be derived from this weapon against cavalry, and for the defence of fortified places, or intrenchments. He observes, that the fougette, in shape, resembles a sky-rocket, whose flight is gradually brought to run along an horizontal direction. By throwing several fougettes into parks of artillery and upon the caissons, &c. considerable damage might be occasioned from the fire which would inevitably be communicated to some part. A fougette forces itself immediately forward, cuts as it penetrates, by the formation of its sides, which are filled with small spikes, becomes combustible and on fire at all its points; and possesses within itself a thousand various means by which it can adhere to whatever object it is destined to set on fire or to destroy. This weapon would be more effectual, because it might be more variously applied, to defend the mouth of a harbor against an enemy’s shipping, than red-hot balls can ever prove. Fougettes might be used on board ships of war, but there would certainly be some danger in the experiment; although, in my humble opinion, a little experience would effectually remove that difficulty; in which case ships might run along a coast, and easily destroy the wooden works that are sometimes erected upon it. They would in the first place occasion more havoc than red-hot balls; and in the next, they might be used whilst the vessel was in full sail; which cannot be done in the first instance. By means of their natural velocity they would do more execution in a less space of time, than the most active piece of ordnance could effect; and they would require fewer hands, as the only necessary operation would be to light and dart them forward. As a defensible weapon it must naturally be allowed, that, where a small body of men is attacked, the fougette might be adopted with considerable advantage.—The writer of this article, who, we find, is likewise the inventor of a fougette which has been submitted to the French government, continues to argue much in favor of its adoption. If, adds he, our enemies should imitate the invention, we must then have recourse, especially in sea-fights to those pieces of ordnance which are calculated to do more execution at a distance; and it will then be our business to contrive fougettes that shall reach their shipping, by means of a greater degree of force and velocity which might be given to them, than they would be capable of attaining. See Rocket.

FOUILLER, Fr. To search. In a military sense, it signifies to detach small bodies of infantry round the flanks of a column that is marching through a wood, for the purpose of discovering an ambuscade, and of giving timely notice that it may be avoided. The same precaution is necessary when a body of men advances towards or enters a village.

FOUNDATION, in military architecture, is that part of a building which is under ground, or the mass of stone, brick, &c. which supports a building, or upon which the walls of a superstructure are raised: or it is the coffer or bed dug below the level of the ground, to raise a building upon; in which sense, the foundation either goes to the whole area or extent of the building, as when there are to be vaults, galleries, casemates, or the like; or is drawn in cuts or trenches, as when only walls are to be raised. Sometimes the foundation is massive, and continued under the whole building, as in the antique arches and aqueducts; but it is more usually in spaces, or intervals; in which latter case, insulated pillars, bound together by arches, should be used.

There are several things to be well considered in laying the foundation of a military building. We must first examine the bed of the earth upon which we are to build, and then the under fillings or substruction. We are not to rest upon any seeming solidity, unless the whole mould through which we cut has likewise been solid; and in such cases, allow ¹⁄₆th part of the height of the building for the hollowing or under-digging, unless there be cellars under ground, in which case it may be something less. There are many ways to try the firmness of the ground; but the following, in our opinion, is the best. Take an iron crow, or such a borer as well-diggers use, which at once will point out the goodness and tenacity of the ground.

Engineers should use the utmost diligence in this point; for, of all the errors that may happen in building, those are the most pernicious which are committed in the foundation, because they bring with them the ruin of the whole building; nor can they be amended without very great difficulty.

Foundations are either natural, or artificial: natural, as when we build on a rock, or very solid earth; in which case we need not seek for any other strengthening; for these, without digging, or other artificial helps, are of themselves excellent foundations, and most fit to uphold the greatest buildings. But if the ground be sandy or marshy, or have lately been dug, in such case recourse must be had to art. In the former case, the engineer must adjust the depth of the foundation by the height, weight, &c. of the building: ¹⁄₆th part of the whole height is looked upon as a medium; and as to the thickness, double that of the width of a wall is a good rule. If you build upon mossy and loose earth, then you must dig until you find sound ground. This sound ground, fit to support a building, is of divers kinds: in some places so hard, as scarcely to be cut with iron; in other places very stiff; in other places blackish, which is accounted the weakest; in others like chalk, and in others sandy: but of all these, that is the best which requires most labor in cutting or digging, and when wet, does not dissolve into dirt.

If the earth to be built upon is very soft, as in moorish grounds, or such that the natural foundation cannot be trusted, then you must get good pieces of oak, whose length should be the breadth of the trench or about 2 feet longer than the wall; these must be laid across the foundation about 2 feet asunder, and being well rammed down, lay long planks upon them; which planks need not lie so broad as the pieces are long, but only about four inches on a side wider than the basis, or foot of the wall is to be. But if the ground be so very bad, that this will not do, then you must provide good piles of oak of such a length as will reach the good ground, and whose diameter must be about ¹⁄₁₂th part of their length. These piles must be driven down by an engine for that purpose, and must be placed as close as one can stand by another; then lay planks upon them, and pin them fast. But if the ground be faulty in some parts, and firm in others, you may turn arches over those loose places, which will discharge them of the weight. You must not forget to place the piles under the inner, as well as the outer walls; for if these should sink, it would be a means to make the outer walls crack, and so ruin the whole building.

Having thus far considered the bed of the earth on which the building is to be erected, we shall next consider the substruction, as it was called by the ancients; but our modern engineers call it the foundation. This is the ground-work of the whole edifice, which must sustain the walls, and may be termed artificial, as the other was natural; with regard to which, the following things are most necessary to be observed: 1. That the bottom be exactly level; therefore lay a platform of good boards. 2. That the lowest ledge or row be all of stone, the broader the better, laid closely without mortar; which is a general caution for all parts of a building that are contiguous to board or timber, because lime and wood are utter enemies to one another, and, if unfit confiners any where, they are more especially so in the foundation. 3. That the breadth of the foundation be at least double the breadth of the wall which is to be raised upon it: but even in this case art should give way to discretion: and the foundation may be made either broader, or narrower, according as the ground and the ponderosity of the edifice require. 4. That the foundation be made to diminish as it rises, but yet so that there may be as much left on the one side as on the other; so that the middle of that above may be perpendicularly over the middle of that below, which should in like manner be observed in diminishing the walls above ground; for by this means the building will become much stronger than it would be if the diminution were made by any other way. 5. That you should never build on the ruins of an old foundation, unless you are well assured of its depth, and that its strength is sufficient to bear the building.

The stones in the foundation should be laid as they naturally lay in the quarry, for they have the most strength in their natural position. This should be observed in all parts of a building, because all stones have a cleaving grain; consequently, if the horizontal position of the stones in the quarry should be placed vertically in the building, the superincumbent weight would be apt to cleave them, and so render the building ruinous.

FOUNDER, a person, who casts cannon, &c.

FOUNDERING, a disorder in horses, which may be considered under two heads, viz.

Foundering in the feet, which is an universal rheumatism, or defluxion of humors upon the sinews of a horse’s feet; so that in the course of time the hoofs become stiff and callous, and the horse has no sense or feeling of them. This disorder is generally brought on by hard riding. Sometimes it proceeds from sudden heats and colds; and frequently from the horse being watered when he is very hot. Too tight a shoe, or frequent travelling upon hard flinty ground, will likewise produce this disorder.

Foundering in the chest, a disorder which may be occasioned by crudities collected in the stomach, or by other infirmities which obstruct the free action of the lungs. It is discovered by the horse not being able to bend his joints, and, when once laid, by not being able to rise again. A swelling in the legs is likewise symptomatic of it.

FOUNDERY, -

FOUNDRY,

in military matters, the art of casting all kinds of ordnance, such as cannon, mortars, howitzers, &c. It likewise signifies the place or work-house wherein these operations are performed. At present all pieces of artillery are cast solid, and bored afterwards. Formerly guns were bored perpendicularly, but at present in a horizontal position: the boring instrument is fixed immoveably, and forced into the gun or mortar by a mechanical power. The piece of artillery is turned round by a large wheel, and at the same time the gun is bored, the outside is turned and polished, by another very curious machine for that purpose, invented by the very ingenious Messrs. Verbruggen, founders at Woolwich. Guns were first founded in England in 1587.

FOURAGE, Fr. Forage. In the artillery, it is used figuratively to signify hay, straw, or any thing else of vegetable growth, which is used to ram into the bore of a cannon for the purpose of cleansing it.

Aller au Fourage, to go a foraging.

FOURAGER, Fr. To forage, or look about for provender and provisions.

Fourager likewise means among the French to ravage, desolate, pillage, and waste a country for the purpose of throwing the inhabitants into disorder. The word is derived from foras agere, or to seek for forage in the fields.

Fourageur, Fr. foragers, or men employed to procure forage, &c. for an army. They are generally escorted. Hence the expression: so many men have been ordered to escort the foragers. The body of foragers has been charged by the enemy’s cavalry.

FOURBISSEURS, Fr. a sword cutler. The French familiarly say of two persons who are extremely intimate, Ces gens sont tête-a-tête comme des fourbisseurs, meaning, that, like sword cutlers, (who when they work sit closely opposite to each other) they are putting their heads together.

Se battre a l’épée qui est chez le fourbisseur, to fight with a sword which is still in the cutler’s hands; signifying figuratively to dispute about any thing that does not concern either party.

FOURGON, Fr. a sort of waggon. It likewise signifies a poker.

FOURNEAU, Fr. furnace, also the chamber of a mine.

FOURIER, Fr. A quarter master belonging to a cavalry or infantry regiment. In France there were fouriers-majors of cavalry who composed a part of the cavalry staff. Serjeant fourier, and corporal fourier, answer to our quarter master serjeant.

FOURNIMENT, Fr. A horn which holds about one pound of gun-powder to prime cannon. It is likewise used by cavalry and infantry soldiers, who hang it across their shoulder. The artillerists keep it in a belt.

FOURCHETTES à mousquet, Fr. Rests for a musquet. They are sometimes used to relieve men who do duty on the rampart of a town.

Chemin Fourchu, a cross way.

Paix FOURREE, Fr. a peace suddenly patched up.

Pays FOURRE, Fr. a country thick set with hedges, &c. properly called a close country.

FOURREAU de pistolet, a holster.

Faux Fourreau de pistolet, pistol bag.

Fourreau d’epée the scabbard of a sword.

Fourmiller, Fr. to swarm with. La France fourmille en braves soldats—France swarms with brave soldiers; L’Angleterre fourmille en braves marins—England swarms with brave seamen.

FOUR de campagne. A field oven.

FOUR, a place of confinement in Paris to which vagabonds and persons who could not give any satisfactory account of themselves were committed; and when once shut up had their names enregistered, and were enlisted for the service of the old French government. A four in this acceptation of the term means a room arched over without having the least aperture to receive day light. There were several such places of confinement in Paris. They owed their invention to a Monsieur D’Argenson, and were supposed to add annually two thousand men at least to the king’s regular army; by which means the capital was relieved from a multitude of thieves, pick-pockets, &c.

FOURNITURES des vivres, Fr. See Stores, &c.

FOYER, Fr. Focus, or centre of the chamber. See Mine.

FRAISE, in fortification, a kind of stakes or palisades placed horizontally on the outward slope of a rampart made of earth, to prevent the work being taken by surprise. They are generally 7 or 8 feet long, and about 5 inches thick. When an army intrenches itself, the parapets of the retrenchments are often fraised in the parts exposed to an attack.

To Fraise a battalion, is to line, or cover it every way with pikes, that it may withstand the shock of a body of horse.

FRAISER, Fr. To plait, knead or drill....In a military sense to fraise or fence; as fraiser un battalion, is to fraise or fence all the musquetry-men belonging to a battalion with pikes, to oppose the irruption of cavalry should it charge them in a plain. At present it means to secure a battalion by opposing bayonets obliquely forward, or cross-ways in such a manner as to render it impossible for a horseman to act against it.

Fraises, Fr. See Fraise an adopted English term.

FRANCHES, Fr....Les compagnies franches, free companies, were bodies of men detached and separated from the rest of the army, having each a chief, or commandant. They consisted chiefly of dragoons, hussars, &c. and their peculiar duty was to make irruptions into an enemy’s country; and may not improperly be called land pirates, as their chief occupation was to harrass and plunder the enemy and his adherents, in whatever manner they could, without paying any regard to military forms. The persons who composed these corps were termed partisans. They always accompanied the main army in time of war, and were distributed among the different garrison towns in France during peace. They were common to every power in Europe; the Pandours and Hulans were of this description. They were the worst afflictions of war; and generally as fatal to their friends as their enemies.

FRAY, a battle, combat, or duel.

FRICTION, in mechanics, the rubbing of the parts of engines and machines against each other, by which a considerable part of their effect is destroyed.

It is hardly possible to lay down general rules for computing the quantity of friction, because it depends upon a multiplicity of circumstances, as the structure, firmness, elasticity, &c. of bodies rubbing against each other. Some authors make the friction upon a horizontal plane, equal to ¹⁄₃d of the weight to be moved; while others have found it to be considerably less. But however this be, the doctrine of friction, as ascertained by the latest experiments, may be summed up in the following manner.

1. When one body rests on another upon a horizontal plane, it presses it with its whole weight, which being equally reacted upon, and consequently the whole effect of its gravity destroyed by the plane, it will be absolutely free to move in any horizontal direction by any the least power applied thereto, provided both the touching surfaces be smooth.

2. But since we find no such thing as perfect smoothness in the surfaces of bodies, arising from their porosity and peculiar texture, it is easy to understand, that when two such surfaces come together, the prominent parts of the one will, in some measure, fall into the concave parts of the other; and therefore, when an horizontal motion is attempted in one, the fixed prominent parts of the other will give more or less resistance to the moving surface, by holding and retaining its parts; and this is what we call friction.

3. Now since any body will require a force equal to its weight, to draw it over a given obstacle, it follows that the friction arising to the moving body, will always be in proportion to its weight only, and not to the quantity of the surface, by which it bears upon the resisting plane or surface. Thus if a piece of wood 4 inches wide, and 1 thick, be laid upon another fixed piece of the same wood, it will require the same weight to draw it along, whether it be laid on its broad or narrow side.

4. For, though there be 4 times the number of touching particles on the broad side (cetæris paribus) yet each particle is pressed with only ¹⁄₄th of the weight, that those are on the narrow side, and since 4 times the number multiplied by one fourth of the weight, it is plain the resistance is equal in both places, and so requires the same force to overcome it.

5. The reason why friction is proportional to the weight of the moving body, is, because the power applied to move the body must raise it over the prominent parts of the surface on which it is drawn; and this motion of the body, as it is not upright, will not require a power equal to its whole weight; but being in the nature of the motion on an inclined plane, it will only require a part of its own weight, which will vary with the various degrees of smoothness and asperity.

6. It is found by experiment, that a body, may be drawn along by nearly ¹⁄₃d of its weight; and if the surfaces be hard and well polished, by less than ¹⁄₃d part; whereas, if the parts be soft or rugged, it will require a much greater weight.

The ingenious Mr. Emerson, in his Principles of Mechanics, has given the following rules deduced from experiments; but they require some variation under different circumstances, which must be left to the judgment of the artist.

1. Wood and all metals, when greased, have nearly the same friction; and the smoother they are, the less friction they have; yet metals may be so far polished as to increase friction by the cohesion of their parts.

Wood slides easier upon the ground in wet weather than in dry, and easier than iron in dry weather; but iron slides easier than wood, in wet weather. Lead makes a great deal of resistance. Iron or steel running in brass, makes the least friction of any. In wood acting against wood, grease makes the motion twice as easy, or rather ²⁄₃ds easier. Wheel-naves, greased or tarred, go 4 times easier than when wet.

Metals oiled make the friction less than when polished, and twice as little as when unpolished.

In general, the softer or rougher the bodies, the less or greater their friction.

2. As to particular cases: a cubic piece of soft wood of 8 pounds weight, moving upon a smooth plane of soft wood, at the rate of 3 feet per second; its friction is about ¹⁄₃d of the weight of it; but if it be rough, the friction is little less than one half the weight.

Upon the same supposition, other soft wood upon soft wood very smooth, the friction is bout ¹⁄₄th of the weight.

Soft wood upon hard, or hard wood upon soft, ¹⁄₅th or 1-half of the weight. Hard wood upon hard wood, ¹⁄₇th or ¹⁄₈th of the weight.

Polished steel moving upon steel or pewter, ¹⁄₄th of the weight; moving on copper or lead, ¹⁄₅th of the weight; on brass, ¹⁄₅th of the weight. Metals of the same sort have more friction than different sorts.

The friction, cæteris paribus, increases with the weight almost in the same proportion. The friction is also greater with a greater velocity, but not in proportion to it, except in very few cases. A greater surface also causes somewhat more friction, with the same weight and velocity; yet friction may sometimes be increased by having too little surface to move on; as upon clay, &c. where the body sinks.

3. The friction arising from the bending of ropes about machines, differs according to their stiffness, the temper of the weather, degree of flexibility, &c., but, cæteris paribus, the force or difficulty of bending a rope is as the square of the diameter of the rope, and its tension, directly; and the diameter of the cylinder or pulley it goes about, reciprocally.

A rope of 1 inch diameter, whose tension or weight drawing it is 5 pounds, going over a pully 3 inches diameter, requires a force of 1 pound to bend it.

4. The resistance of a plane moving through a fluid is as the square of the velocity; and putting v = velocity in feet in a second; it is equal to the weight of a column of the fluid, whose base is the plane, and height vvb4. And in a globe it is but half so much.

5. As to the mechanic powers, the single lever makes no resistance by friction; but if, by the motion of the lever in lifting the fulcrum, or place of support, be changed further from the weight, the power will be decreased thereby.

6. In any wheel of any machine, running upon an axis, the friction on the axis is as the weight upon it, the diameter of the axis, and the angular velocity. This sort of friction is but small.

7. In the pully, if p, q, be 2 weights, and q the greater; and w = 4pqpxq then w is the weight upon the axis of the single pulley; and it is not increased by the acceleration of the weight q, but remains always the same.

The friction of the pullies is very considerable, when the sheaves rub against the blocks; and by the wearing of the holes and axles.

The friction of the axis of the pulley is as the weight w, its angular velocity, the diameter of the axis directly, and the diameter of the pully inversely. A power of 100 pounds, with the addition of 50 pounds, will only draw up 500 with a tackle of 5; and 15 pounds over a single pully will draw up only 14 pounds.

8. In the screw, there is a great deal of friction: those with sharp threads have more friction than those with square threads; and endless screws have more than either. Screws, with a square thread, raise a weight with more ease than those with a sharp thread.

In the common screw the friction is so great, that it will sustain the weight in any position given, when the power is taken off; and therefore the friction is at least equal to the power. From whence it will follow, that in the screw, the power must be to the weight or resistance, at least as twice the perpendicular height of a thread to the circumference described by one revolution of the power; if it be able to raise the weight, or only sustain it. This friction of the screw is of great use, as it serves to keep the weight in any given position.

9. In the wedge, the friction is at least equal to the power, as it retains any position it is driven into; therefore in the wedge, the power must be to the weight at least as twice the base to the height, to overcome any resistance.

10. To find the friction of any engine, begin at the power, and consider the velocity and the weight at the first rubbing part; and estimate its quantity of friction by some of the foregoing articles; then proceed to the next rubbing part, and do the same for it, and so on through the whole.

And note that something more is to be allowed for increase of friction by every new addition to the power.

FRILL. An ornamental appendage to the shirt which officers and soldiers generally wear with regimentals. A small aperture is usually made at the top to admit the hook and eye of the uniform coat. Detached frills for the privates are certainly preferable to those which are fixed to the shirts, as three per week, at the regular times allotted for a change of linen, would answer every purpose of cleanliness.