Chapter D: Caldwell, (18)

In this manner every other division proceeds; each officer advancing, with a firm, steady step, in a perpendicular direction towards his point of formation, while the flank serjeant remains at his point in the line, till the succeeding officer, who has dressed his division, arrives to replace him; after which the serjeant covers his own officer.

_To_ FORM _on a rear division_, is to face all the preceding divisions which are in column to the right, (the point of forming having been previously taken in that direction, as far as the prolongation of the head division will extend, and just beyond where the right of the battalion is to come) and to uncover the rear one, so as to enable it to advance forward to a given point on the left, and take up its place in the alignement.

The leader of the front or head division having been shewn the distant point in the alignement on which he is to march, and having taken his intermediate points, if necessary, at the word _march_, the faced divisions step off quick, heads of files are dressed to the left, the front one moves in the alignement with scrupulous exactitude, and the others continue in a parallel direction close on its right; each carefully preserving its relative points of prolongation, and being fronted by its officer the instant it gets upon the ground, which is perpendicular to its intended formation in line.

As soon as the rear division is uncovered, and has received the word _march_, it proceeds forward, and when arrived within a few paces of its ground, the officer commanding steps nimbly up to the detached officer or serjeant, who has carefully marked its left in the new position, gives the words _dress_, _halt_, and quickly corrects his division on the distant point of formation; after which he replaces his serjeant on the right of his division. As the officer who conducts this division has necessarily the longest extent of ground to march on, he must take especial care to observe his perpendicular direction, constantly keeping the different points of formation in his eye, and preserving a perfect squareness of person. The intermediate divisions will successively proceed and advance as the ground opens before them.

_To_ FORM _on a central division_. To execute this manœuvre, the front and rear divisions must deploy, or open, so as to uncover the named division, and enable it to move up to a given point of alignement. A forming point must be given to both flanks in the prolongation of the head division.

When the caution of forming on a central division has been given, the leading officers will shift to the heads of their several divisions, the instant they have been faced according to the hand which leads to their ground. The files during their deployment must be kept close, and well locked up; and when fronted, must instantly be corrected in their dressing before they march forward. The central division, when uncovered, moves up into line to its marked flank. Those that were in front of it proceed as in forming on a rear division; those that were in rear of it proceed as in forming on a front division. By means of those three formations, which are effected by the deployment, or flank march, every battalion in close column, may uncover and extend its several divisions. The previous formation of close column upon given proportions of a brigade, battalion, &c. is done by facing and moving _inwards_, and thus contracting the original line with any given division for the head; which line may again be restored by the different divisions facing and moving _outwards_, as we have just described.

_To_ FORM _line on a rear company of the open column standing in echellon_, that company remains placed; the others face about, wheel back on the pivot flanks of the column, as being those which afterwards first come into line. On the word _march_, they move forward, and then _front_, _halt_, _dress_, successively, in the line of the rear company.

_To_ FORM _line on the rear company facing to the rear of the open column standing in echellon_, the whole column must first countermarch, each company by files, and then proceed as in forming on a front company.

_To_ FORM _line on a central company of the open column_, that company stands fast, or is wheeled on its own centre into a new required direction. Those in front, must be ordered to _face_ about. The whole, except the central company, must wheel back the named number of paces. Those in front, on the proper pivot flanks of the column, and those in its rear on the reverse flanks, such being the flanks that first arrive in line. The whole then marches in line with the central company. See _Am. Mil. Lib._

_To_ FORM _line from close column on a rear company facing to the rear_, the whole of the column changes front by countermarching each company by files. The rear company stands fast, and the remaining companies face to the right, deploy, successively _front_, _halt_, _dress_, and move up into the alignement.

_To_ FORM _line from close column on a central company facing to the rear_, the central company countermarches and stands fast; the other companies face outwards, countermarch, deploy, and successively march up to the alignement.

Whenever the column is a retiring one, and the line is to front to the rear, the divisions must each countermarch before the formation begins. In which case the head would be thrown back, and the rear forward.

_To_ FORM _en potence_, to wheel the right or left flank of a body of men, or to march them forward by files, so as to make that proportion of a line face inwards, and resemble a potence or angle. A double potence may be formed by running out both flanks, so that they stand in a perpendicular direction facing towards each other like the letter Λ, or thus, \__/; these oblique lines are the potence, so named by the power of their cross fire. This formation is not only extremely useful on actual service, but it conduces greatly to the accommodation of any body of men which may be marched into a place that has not sufficient extent of ground to receive it in line.

FORMATION, in a military sense, the methodical arrangement, or drawing up of any given body of men mounted, or on foot, according to prescribed rules and regulations.

_Cavalry_ FORMATION, consists of the following proportions.

Squadrons of cavalry are composed each of two troops; regiments are composed of ten.

FORMATION _of a troop_, is the drawing out of a certain number of men on horseback on their troop parade, in a rank entire, fixed according to the size roll, the tallest men in the centre.

FORMATION _of the squadron_, is the military disposition of two troops that compose it closed into each, from their several troop parades. In this situation, the officers move out, and form in a rank advanced two horses length, fronting to their troops. The serjeants and covering corporals rein back, and dress with the quarter-master in the rear. When the formation of a squadron has been completed, and its component parts have been accurately told off, the commanding officer is advanced a horse’s length before the standard. Two officers are posted, one on each flank of the front rank, covered by a non-commissioned officer. One officer is posted in the centre of the front rank with the standard, and is covered by a corporal. The serjeants are placed, one on the right of the front of each of the four divisions, except the right one, and each is covered by a corporal or private dragoon. The serre-files or supernumerary officers and serjeants, the quarter-masters and trumpeters, are in the rear of their several troops, divided in a line, at two horses distance from the rear rank. Farriers are behind the serre-files a horse’s length. Allowance is always made for sick and absent officers and non-commissioned officers; and if a sufficient number of any rank is not present, then serjeants replace officers, corporals replace serjeants, and lance-corporals or intelligent men replace corporals.

Formation, considered as to general circumstances, admits of a few deviations from the strict letter of the term. In order to preserve each troop entire, it is not material, if one division be a file stronger than another. The flank divisions indeed, both in cavalry and infantry regiments, will be strongest from the addition of officers. Officers, in the formation of squadrons, are recommended to be posted with their troops. Corporals not wanted to mark the divisions, or to cover officers or serjeants, will be in the ranks according to their size, or be placed in the outward flank file of their troops. Farriers are considered as detached in all situations of manœuvre.

All these general circumstances of formation apply and take place, whether the squadron be composed of two, or more troops, and whether the troops be more or less strong.

_General modes of_ FORMATION, are when a regiment broken into and marching in open column, must arrive at and enter on the ground on which it is to form in line, either in the _direction_ of that line, _perpendicular_ to that line, or in a direction more or less _oblique_ betwixt the other two.

_Infantry_ FORMATION, is the arrangement or disposition of any given number of men on foot according to prescribed rules and regulations. When the companies join, which are generally ten in number, the battalion is formed; there is not to be any interval between the relative parts, but the whole front must present a continuity of points, and one compact regular line from one flank file to the other.

The formation or drawing up of the companies will be from right to left. There is much folly prevalent on the subject of positions of companies. Steuben’s work has endeavored to fix a plan of alternation; but failed. A simple principle would be to number the companies from right to left, and form the first battalion of 1, 3, 5, 7, 9, and the second of 2, 4, 6, 8, 10. Officers commanding companies or platoons are all on the right of their respective ones.

The eight battalion companies will compose four grand divisions--eight companies or platoons--sixteen subdivisions--thirty-two sections, when sufficiently strong to be so divided, otherwise twenty-four, for the purposes of march. The battalion is likewise divided into right and left wings. When the battalion is on a war establishment, each company will be divided into two equal parts. When the ten companies are with the battalion, they may then be divided into five grand divisions from right to left. This is done to render the firings more exact, and to facilitate deploy movements.

The battalion companies will be numbered from the right to the left 1. 2. 3. 4. 5. 6. 7. 8. The subdivisions will be numbered 1. 2. of each. The sections will be numbered 1. 2. 3. 4. of each. The files of companies will also be numbered 1. 2. 3. 4. &c. the grenadier and light companies will be numbered seperately in the same manner, and with the addition of those distinctions. No alteration is to be made in these appellations whether the battalion be faced to front or rear.

FORMATION _at close order_, is the arrangement of any given number of men in ranks at the distance of one pace, except where there is a fourth, or supernumerary rank, which has three paces. In firing order the ranks are more closely locked in.

When a battalion is formed in close order, the field officers and adjutant are mounted. The commanding officer is the only officer advanced in front for the general purpose of exercise, when the battalion is single; but in the march in line, and during the firings, he is in the rear of the colors. The lieutenant colonel is behind the colors, six paces from the rear rank. The major and adjutant are six paces in the rear of the third and sixth companies. One officer is on the right of the front rank of each company or platoon, and one on the left of the battalion. All these are covered in the rear by their respective serjeants, and the remaining officers and serjeants are in a fourth rank behind their companies. There are no coverers in the centre rank to officers or colors. The colors are placed between the fourth and fifth battalion companies, both in the front rank, and each covered by a non-commissioned officer, or steady man in the rear rank. One serjeant is in the front rank betwixt the colors; he is covered by a second serjeant in the rear rank, and by a third in the supernumerary rank. The sole business of these three serjeants is, when the battalion moves in line, to act as guides, and direct the march according to prescribed instructions. The place of the first of those serjeants, when they do move out, is preserved by a named officer or serjeant, who moves up from the supernumerary rank for that purpose. The pioneers are assembled behind the centre, formed two deep, and nine paces from the third rank. The drummers of the eight battalion companies are assembled in two divisions, six paces behind the third rank of their 2d and 7th companies. The music are three paces behind the pioneers, in a single rank, and at all times, as well as the drummers and pioneers, are formed at loose files only, occupying no more space than is necessary. The staff officers are three paces behind the music.

FORMATION _at open order_, is any open disposition, or arrangement of men by ranks, at straight lines parallel to each other.

When a battalion is directed to take open order, the rear ranks fall back one and two paces, each dressing by the right the instant it arrives on the ground. The officers in the front rank, as also the colors, move out three paces. Those in the rear, together with the music, advance through the intervals left open by the front rank officers, and divide themselves in the following manner: the captains covering the second file from the right, the lieutenants the second file from the left, and the ensigns opposite the centre of their respective companies. The music form between the colors and the front rank. The serjeant coverers move up to the front rank, to fill up the intervals left by the officers. The pioneers fall back to six paces distance behind the centre of the rear rank. The drummers take the same distance behind their divisions. The major moves to the right of the line of officers; the adjutant to the left of the front rank. The staff place themselves on the right of the front rank of the grenadiers. The colonel and lieutenant-colonel dismounted, advance before the colors four and two paces.

FORMERS, round pieces of wood that are fitted to the diameter of the bore of a gun, round which the cartridge paper, parchment, lead, or cotton is rolled before it is sewed.

FORMERS were likewise used among officers and soldiers to reduce their clubs to an uniform shape, before the general introduction of tails.

FORMATION _of guards_. See GUARDS.

FORT, in the military art, a small fortified place, environed on all sides with a ditch, rampart, and parapet. Its use is to secure some high ground, or the passage of a river, or to make good an advantageous post, to defend the lines and quarters of a siege, &c.

Forts are made of different figures and extents, according to the exigency of the service, or the peculiar nature of the ground. Some are fortified with bastions, others with demi-bastions. Some are in form of a square, others of a pentagon. Some again are made in the form of a star, having 5 or 7 angles. A fort differs from a citadel, the last being built to command some town. See CITADEL.

_Royal_-FORT, one whose line of defence is at least 26 toises long.

_Triangular_ FORTS, are frequently made with half bastions; but they are very imperfect, because the faces are not seen or defended from any other part. If, instead of being terminated at the angle, they were directed to a point about 20 toises from it, they would be much better, as then they might be defended by that length of the rampart, though but very obliquely. The ditch ought to be from 8 to 10 toises. Sometimes instead of half bastions at the angles, whole ones are placed in the middle of the sides. The gorges of these bastions may be from 20 to 24 toises, when the sides are from 100 to 120; the flanks are perpendicular to the sides, from 10 to 12 toises long; and the capitals from 20 to 24. If the sides happen to be more or less, the parts of the bastions are likewise made more or less in proportion. The ditch round this fort may be 10 or 12 toises wide.

The ramparts and parapets of these sorts of works are commonly made of turf, and the outside of the parapet is fraised; that is, a row of pallisades are placed about the middle of the slope, in an horizontal manner, the points declining rather a little downwards, that the grenades or fireworks thrown upon them may roll down into the ditch; and if the ditch is dry, a row of pallisades should be placed in the middle of it, to prevent the enemy from passing over it unperceived, and to secure the fort from any surprise.

FORT _de campagne_, _Fr._ a field fortification, See FORTIFICATION.

FORTERESSE, _Fr._ Fortress. Any strong place rendered so by art, or originally so by local advantages, or by means of both nature and art. Places which are strong by nature generally stand upon mountains, precipices, in the middle of a marsh, on the sea-coast, in a lake, or on the banks of some large river. Places which are strong by art, owe their strength to the labor of man, whose ingenuity and perseverance substitute ditches and ramparts where mountains and rivers are wanting.

FORTIFICATION, is the art of fortifying a town, or other place; or of putting it in such a posture of defence, that every one of its parts defends, and is defended by some other parts, by means of ramparts, parapets, ditches, and other outworks; to the end that a small number of men within may be able to defend themselves for a considerable time against the assaults of a numerous army without; so that the enemy, in attacking them, must of necessity suffer great loss.

_Fortification_ may be divided into ancient and modern; offensive, and defensive; regular, and irregular; natural, and artificial, &c.

_Ancient_ FORTIFICATION, at first, consisted of walls or defences made of trunks, and other branches of trees, mixed with earth, for security against the attacks of an enemy. Invention owes its origin to necessity; _fortification_ seems to have had fear for its basis; for when man had no other enemy but the wild beasts, the walls of his cottage were his security; but when pride, ambition, and avarice, had possessed the minds of the strong and the daring to commit violences upon their weaker neighbors, either to subject them to new laws, or to plunder their little inheritance, it was natural for the latter to contrive how to defend themselves from such injuries.

Our Aborigines of North America, have left traces of _fortification_ in its infancy, of which there are some curious and magnificent remains on the _Miami_ river, in the state of Ohio.

There are abundance of Indian villages fenced round by long stakes driven into the ground, with moss or earth to fill the intervals; and this is their security (together with their own vigilance) against the cruelty of the savage neighboring nations.

Nor is _fortification_ much less ancient than mankind; for Cain, the son of Adam, built a city with a wall round it upon mount Liban, and called it after the name of his son Enoch, the ruins of which, it is said, are to be seen to this day; and the Babylonians, soon after the deluge, built cities and encompassed them with strong walls.

At first people thought themselves safe enough with a single wall, behind which they made use of their darts and arrows with safety: but as other warlike instruments were continually invented to destroy these feeble structures, so on the other hand persons acting on the defensive were obliged to build stronger and stronger to resist the new contrived forces of the desperate assailants.

What improvements they made in strengthening their walls many ages ago, appear from history. The first walls we ever read of, and which were built by Cain, were of brick; and the ancient Grecians, long before Rome was ever thought of, used brick and rubble stone, with which they built a vast wall, joining mount Hymetus to the city of Athens. The Babylonian walls, built by Semiramis, or, as others will have it, by Belus, were 32 feet thick, and 100 feet high, with towers 10 feet higher, built upon them, cemented with bitumen or asphaltus. Those of Jerusalem seem to have come but little short of them, since, in the siege by Titus, all the Roman battering rams, joined with Roman art and courage, could remove but 4 stones out of the tower of Antonia in a whole night’s assault.

After _fortification_ had arrived at this height it stopped for many ages, ’till the use of gunpowder and guns was found out; and then the round and square towers, which were very good flanks against bows and arrows, became but indifferent ones against the violence of cannon; nor did the battlements any longer offer a hiding place, when the force of one shot both overset the battlement, and destroyed those who sought security from it.

_Modern_ FORTIFICATION, is the way of defence now used, turning the walls into ramparts, and square and round towers into bastions, defended by numerous outworks; all which are made so solid, that they cannot be beat down, but by the continual fire of several batteries of cannon. These bastions at first were but small, their gorges narrow, their flanks and faces short, and at a great distance from each other, as are those now to be seen in the city of Antwerp, built in 1540 by Charles V. emperor of Germany; since which time they have been greatly improved and enlarged, and are now arrived to that degree of strength, that it is almost a received opinion, that the art of fortification is at its height, and almost incapable of being carried to a much greater perfection.

_Offensive_ FORTIFICATION, shews how to besiege and take a fortified place; it further teaches a general how to take all advantages for his troops; the manner of encamping, and method of carrying on either a regular or irregular siege, according as circumstances may direct.

_Defensive_ FORTIFICATION, shews a governor how to make the most of a garrison committed to his care, and to provide all things necessary for its defence.

_Regular_ FORTIFICATION, is that built in a regular polygon, the sides and angles of which are all equal, being commonly a musquet shot from each other, and fortified according to the rules of art.

_Irregular_ FORTIFICATION, on the contrary, is that where the sides and angles are not uniform, equi-distant, or equal; which is owing to the irregularity of the ground, vallies, rivers, hills, and the like.

_To_ FORTIFY _inwards_, is to represent the bastion within the polygon proposed to be fortified; and then that polygon is called the _exterior polygon_, and each of its sides the _exterior side_, terminating at the points of the two nearest bastions.

_To_ FORTIFY _outwards_, is to represent the bastion without the polygon proposed to be fortified, and then the polygon is called the _interior polygon_, and each of its sides the _interior side_, terminating in the centres of the two nearest bastions.

_Elementary_ FORTIFICATION, by some likewise called the theory of fortification, consists in tracing the plans and profiles of a fortification on paper, with scales and compasses; and examining the systems proposed by different authors, in order to discover their advantages and disadvantages. The elementary part is likewise divided into regular and irregular fortification, which see.

_Front_ FORTIFICATION, any proportion of the body of a place, consisting of two half bastions and a curtain.

_Practical_ FORTIFICATION, consists in forming a project of a fortification, according to the nature of the ground, and other necessary circumstances, to trace it on the ground, and to execute the project, together with all the military buildings, such as magazines, store houses, barracks, bridges, &c.

_The names of every part of a_ FORTIFICATION; and first of lines, which are divided into right lines, and curve lines.

_Line of defence_, is the distance between the saliant angle of the bastion, and the opposite flank; that is, it is the face produced to the flank. Common experience, together with some of the greatest artists in fortification, unanimously agree, that the _lines of defence_ may extend (though not exceed) 150 fathom. Some indeed will affirm, that as a musquet does not carry more than 130 fathom point blank, the angle of the bastion should be no further removed from its opposite flank. We agree that a musquet carries no farther point blank; but we are sure it will do execution, and kill, at 180 fathom. The enemy generally makes his breaches near the middle of the face; which if granted, the line of fire from the flank to the breach, scarcely exceeds 130 fathom; besides, the cannon of the flank does less execution upon a short _line of defence_ than on a long one.

_Line of defence fichant_, is a line drawn from the angle of the curtain, to the point of the opposite bastion, which is not to exceed 120 fathom; and from the point of the curtain, and flank, to the face of the opposite bastion, which is to be defended. This line may not improperly be called in good English the _butting flank_, since it partly sees the opposite faces in reverse; and the shot from it, especially near the orillon, strike against the faces. Authors are numerous both for and against the _fichant_ and _rasant_ lines; we can only set down as a fixed rule, that the more powerful the active quality is, the more the passive must suffer; that in fortification the active quality is the fire, which discovers the assailants (who are the passive) going to attack the face of the opposite bastion; consequently, the more this active quality is augmented, by so much the more must the passive subjects suffer; and from thence we argue for the _fichant flank_, since it augments this active quality, by all the fire of the curtain added to the flank, which is the principal action in the art of defence.

_Line of defence rasant_, is a line drawn from the point of the bastion along the face, ’till it comes to the curtain, which shews how much of the curtain will clear, or defend the face. This line may very justly in our language be called the _sweeping flank_; because the shot as it were sweeps along the opposite faces. This line, as well as the _fichant_, has many supporters, and as many opponents. In our humble opinion, the _line fichant_ is preferable to the _line rasant_.

_Line of circumvallation._ See SIEGE. See CIRCUMVALLATION.

_Line of contravallation._ See CONTRAVALLATION.

_Line of counter-approach._ See APPROACHES.

_Capital line_, is an imaginary line which divides the work into two equal and similar parts, or a line drawn from the point of the bastion to the point where the two demi-gorges meet, &c.

_Line of defence prolonged_. In the square, and most polygons of the lesser fortification, you prolong the line of defence; but in the polygons of the greater and meaner, you draw a line from the angle of the opposite shoulder to the angle of the curtain, upon which you raise a perpendicular, which serves for the first line of the flank.

_Names of the angles in a_ FORTIFICATION.

_Angle of the centre_, in a polygon, is formed by two radii drawn to the extremities of the same side, or from the centre, terminating at the two nearest angles of the figure.

_Angle of a bastion_, _Flanked angle_, that which is made by the two faces, being the outermost part of the bastion, most exposed to the enemy’s batteries, frequently called the saliant angle, or point of the bastion.

_Angle of the polygon_, is made by the concourse of two adjacent sides of a polygon, in the centre of the bastion.

_Angle of the triangle_, is half the angle of the polygon.

_Angle of the shoulder_, _Angle of the epaule_, is made by the face and flank of the bastion.

_Angle of the flank_, _Angle of the curtain_ that which is made by, and contained between the curtain and the flank.

_Angle of the tenaille_, _Flanking angle_, made by two lines fichant, that is, the face of the two bastions extended till they meet in an angle towards the curtain, and is that which always carries its point towards the work.

_Dead-angle_. Every angle is so called, that points inwards, or is not well defended.

_Angle of the ditch_, is formed before the centre of the curtain, by the outward line of the ditch.

_Angle rentrant_, _Re-entering angle_, is any angle whose point turns inwards, or towards the place; that is, whose legs open towards the field.

_Saliant angle_, is that which points outwards or whose legs open towards the place.

_Angle of the complement of the line of defence_, is the angle formed by the intersection of the two complements with each other.

_Inward flanking angle_, that which is made by the flanking-line and the curtain. See ANGLE.

_Names of the solid works of a_ FORTIFICATION.

_Advanced-foss_, _Avant-fossé_, or ditch, made at the foot of the glacis: it is but very seldom made, because it is easily taken, and serves for a trench to the besiegers.

_Appareille_, is that slope or easy ascent which leads to the platform of the bastion, or to any other work, where the artillery, &c. are brought up and carried down.

_Approaches_, are a kind of roads or passages sunk in the ground by the besiegers, whereby they approach the place under cover of the fire from the garrison.

_Area_, the superficial content of a rampart, or other work.

_Arrow_, is a work placed at the saliant angle of the glacis, and consists of two parapets, each about 40 fathoms long; this work has a communication with the covert-way, of about 24 or 28 feet broad, called a caponniere, with a ditch before it of about 5 or 6 fathom, and a traverse at the entrance, of three fathom thick, and a passage of 6 or 8 feet round it.

_Banquette_, whether single or double, is a kind of step made on the rampart of a work near the parapet, for the troops to stand upon, in order to fire over the parapet: it is generally 3 feet high when double, and 1¹⁄₂ when single, and about 3 feet broad, and 4¹⁄₂ feet lower than the parapet.

_Bastion_, is a part of the inner inclosure of a fortification, making an angle towards the field, and consists of 2 faces, 2 flanks, and an opening towards the centre of the place, called the gorge: or it is rather a large mass of earth, usually faced with sods, sometimes with brick, but rarely with stone; having the figure described.

With regard to the first invention of bastions, there are many opinions amongst authors. Some have attributed this invention to Zisca, the Bohemian; others to Achmet Bashaw, who having taken Otranto in the year 1480, fortified it in a particular manner, which is supposed to be the first instance of the use of bastions. Those who wrote on the subject of fortification 200 years ago, seem to suppose, that bastions were a gradual improvement in the ancient method of building, rather than a new thought, that any one person could claim the honor of. It is certain, however, that they were well known soon after the year 1500; for in 1546, Tartalea published _Quesiti & inventioni diverse_, in the 6th book of which he mentions, that whilst he resided at Verona (which must have been many years before) he saw bastions of a prodigious size: some finished, and others building: and there is besides, in the same book, a plan of Turin, which was then fortified with 4 bastions, and seems to have been completed some time before.

The great rule in constructing a bastion is, that every part of it may be seen and defended from some other part. Mere angles are therefore not sufficient, but flanks and faces are likewise necessary. The faces must not be less than 50 fathom, nor more than 65. The longer the flanks are the greater is the advantage which can be derived from them. They must therefore stand at right angles with the line of defence. At the same time the disposition of the flanks makes the principal part of a fortification, as on them the defence chiefly depends; and it is this that has introduced the various kinds of fortifying.

The angle of the bastion must exceed 60°; otherwise it will be too small to give room for the guns, and will either render the line of defence too long, or the flanks too short. It must therefore be either a right angle or some intermediate one between that and 60 degrees.

_Full bastions_ are best calculated for intrenchments, which are thrown up at the gorge, or by means of a cavalier, whose faces are made parallel to those of the bastion at the distance of 15 toises; having its flanks at the distance of 12 toises, and a ditch measuring 5.

_Large bastions_ have the advantage of small ones, for this palpable reason; the bastion being considered the weakest part of the body of a place, is always attacked; when there is room for troops, cannon and mortars, its natural weakness is greatly remedied.

_Gorge of a bastion_, the interval between the extremity of one flank and that of the next.

_Flat bastion._ When a bastion upon a right line is so constructed, that its demi-gorges do not form an angle, it is called a flat bastion.

_Gorge of a flat bastion_, is a right line, which terminates the distance between two flanks.

_Solid bastion_, _Full bastion_, A bastion is said to be solid or full, when the level ground within is even with the rampart; that is, when the inside is quite level, the parapet being only more elevated than the rest. Solid bastions have this advantage over others, that they afford earth enough to make a retrenchment, in case the enemy lodge themselves on the top of the bastion, and the besieged are resolved to dispute every inch of ground.

_Hollow bastion_, _Empty bastion_, is that where the level ground within is much lower than the rampart, or that part next to the parapet, where the troops are placed to defend the bastion. The disadvantage of these kinds of bastions is, the earth being so low, that when an enemy is once lodged on the rampart, there is no making a retrenchment towards the centre, but what will be under the fire of the besiegers.

_Detached bastion_, is that which is separated or cut off from the body of the place, and differs from a half moon, whose rampart and parapet are lower, and not so thick as those of the place, having the same proportion with the works of the place. Counter-guards with flanks are sometimes called detached bastions.

_Cut bastion_, is that whose saliant angle or point is cut off, instead of which it has a re-entering angle, or an angle inwards. It is used, either when the angle would, without such a contrivance, be too acute, or when water, or some other impediment, prevents the bastion from being carried to its full extent.

_Composed bastion_, is when two sides of the interior polygon are very unequal, which also renders the gorges unequal; it may not improperly be called a _forced bastion_, being as it were forced into that form.

_Deformed bastion_, is when the irregularity of the lines and angles causes the bastion to appear deformed, or out of shape.

_Demi-bastion_, is composed of one face only, has but one flank, and a demi-gorge.

_Double bastion_, is that which is raised on the plane of another bastion, but much higher; leaving 12 or 18 feet between the parapet of the lower, and the foot of the higher; and is sometimes in the nature of a cavalier.

_Regular bastion_, is that which has its true proportion of faces, flanks, and gorges.

_Irregular bastion_, is that wherein the above equality of just proportion is omitted.

_Barriers_, in fortification, a kind of rails to stop the horse or foot from rushing in upon the besieged with violence. In the middle of this kind of defence there is a moveable bar of wood, which opens or shuts at pleasure.

_Berm_, is a little space or path, of 4 to 8 feet broad, between the ditch and the talus of the parapet; it is to prevent the earth from rolling into the ditch, and serves likewise to pass and repass. As it is in some degree advantageous to the enemy, in getting footing, most of the modern engineers reject it.

_Bonnet_, in fortification, is a sort of work placed before the saliant angle of the ravelin to cover it: it consists of 2 faces, parallel to the ravelin, or perpendicular to those of the lunette. They are generally made 10 fathom broad at the ends with a ditch of the same breadth, the covert-way 6, and the glacis 20 fathom.

_Breach_, is on opening or gap made in a wall or rampart, with either cannon or mines, sufficiently wide for a body of troops to enter the works, and drive the besieged out of it.

_Practical breach_, is that where men may mount, and make a lodgment, and should be 15 or 20 feet wide.

_Capital of a work_, is an imaginary line which divides that work into two equal parts.

_Capital of a bastion_, a line drawn from the angle of the polygon to the point of the bastion, or from the point of the bastion to the centre of the gorge. These capitals are from 35 to 40 toises in length, from the point of the bastion to the place where the two demi-gorges meet; being the difference between the exterior and the interior radii.

_Caponnier_ is a passage made in a dry ditch from one work to another: when it is made from the curtain of the body of the place to the opposite ravelin, or from the front of a horn or crown-work, it has a parapet on each side, of 6 or 7 feet high, sloping in a glacis of 10 or 12 toises on the outside to the bottom of the ditch; the width within is from 20 to 25 feet, with a banquette on each side: there is a brick wall to support the earth within which only reaches within 1¹⁄₂ foot of the top, to prevent grazing shot from driving the splinters amongst the defendants.

_Caponnieres_ with two parapets may properly be called double; as there are some made with one rampart only, in dry ditches of the ravelin, and in that of its redoubt, towards the saliant angles, and to open towards the body of the place.

_Caponnieres_, made from the body of the place to the out-works, are sometimes arched over, with loop-holes to fire into the ditch. The single ones in the ditch of the ravelin and redoubt are likewise made with arches open towards the place; for by making them in this manner, the guns which defend the ditch before them, can no other way be dismounted than by mines.

_Cascanes_, in fortification, a kind of cellars made under the capital of a fortification; also subterraneous passages or galleries to discover the enemy’s mines.

_Casemate_, in fortification, is a work made under the rampart, like a cellar or cave with loop-holes to place guns in it.

_Cavaliers_, are works, raised generally within the body of the place, 10 or 12 feet higher than the rest of the works. Their most common situation is within the bastion, and they are made much in the same form: they are sometimes placed in their gorges, or on the middle of the curtain, and then are in the form of a horse-shoe, only flatter.

The use of cavaliers is, to command all the adjacent works and country round them: they are seldom or never made, but when there is a hill or rising ground which overlooks some of the works.

_Centre_, the middle point of any work. From the _centre_ of a place are drawn the first lines to lay down the form of a _fortification_.

_Centre of the bastion_, is that point where the two adjacent curtains produced intersect each other.

_Citadel_, is a kind of fort, or small fortification, of 4, 5, or 6 sides; sometimes joined to towns, &c. Citadels are always built on the most advantageous ground. They are fortified towards the city, and towards the country; being divided from the former by an esplanade, or open place: and serving in one case to overawe the inhabitants; and in the other, not only to hinder the approach of an enemy; but to become a retreat to the garrison, should the town be taken.

_Coffers._ See COFFERS.

_Command_ is when a hill or rising ground overlooks any of the works of a _fortification_, and is within reach of common shot; such a hill is said to command that work. See COMMAND.

_Complement of the curtain_, is that part of the interior side which forms the demi-gorge.

_Complement of the line of defence_, is a _horn-work_ with a _crown-work_ before it. See CROWN-WORK.

_Cordon_, in fortification, is a round projection made of stone, in a semi-circular form, whose diameter is about 1 foot, and goes quite round the wall, and within 4 feet from the upper part.

The cordon being placed on the top of the revetement of the scarp, is a considerable obstacle to the besiegers, when they attempt to storm a place by applying scaling ladders to the scarp.

_Covert-way_ is a space of five or six toises broad, extending round the counterscarp of the ditch, and covered by a parapet from six to seven feet and a half high, having a banquette: the superior part of this parapet forms a gentle slope towards the country, which terminates at the distance of twenty to twenty five toises; this slope is called the glacis.

Sometimes the covert-way is sunk 2 or 3 feet below the horizon of the field; for, as such works are never made to discover the enemy in their trenches, so this method of lowering the covert-way will give room for the fire of the lower curtain (in works that have one) to scour the esplanade; and the expence of it should be the most material objection against it.

_Counter-forts_, in fortification, are by some called _buttresses_; they are solids of masonry, built behind walls, and joined to them at 18 feet distance from the centre to centre, in order to strengthen them, especially when they sustain a rampart or terrace.

_Counter-guard_, in fortification is a work placed before the bastions to cover the opposite flanks from being seen from the covert way. It is likewise made before the ravelins.

When counter-guards are placed before the collateral bastions, they are esteemed of very great use, as the enemy cannot batter them without having first secured the possession of the counter-guards. They were first invented by Pasino, in 1579, and greatly improved by Speckle, in 1589.

_Counterscarp_, is properly the exterior talus of the ditch, or that slope which terminates its breadth, and is the further side from the body of the place. It is so called from being opposite to the scarp.

_Crown-work_, in fortification is a kind of work not unlike a crown: it has 2 fronts and 2 branches. The fronts are composed of 2 half bastions and 1 whole one: they are made before the curtain or the bastion, and generally serve to enclose some buildings which cannot be brought within the body of the place, or to cover the town-gates, or else to occupy a spot of ground which might be advantageous to an enemy. They are of such an expence, that they are rarely found in practice. The best use this work can possibly be put to, is to cover 2 joining curtains, when the sides of it will be parallel to the sides of the place, and it should be fortified with the same strength, and in the same manner.

The authors who have written on the subject, have never thought of this useful part; and we often see 2 horn-works put in practice to cover two curtains, where crown-work would do it much cheaper and much better. The crown-work is adopted for the same purposes as the horn-work.

_Crowned horn-work_, is a _horn-work_ with a _crown-work_ before it. See CROWN-WORK.

_Curtain_, in fortification, is that part of the body of the place, which joins the flank of one bastion to that of another. The straight curtains have always been preferred to the different designs which have been proposed, of which some have diminished the expence, and (at the same time) the strength of the place, others have somewhat augmented the strength, but greatly diminished its area.

_Cuvette_, _Cunette_, in fortification, is a small ditch from 15 to 20 feet broad, made in the middle of a large dry ditch, serving as a retrenchment to defend the same, or otherwise to let water into it, when it can be had during a siege.

When there is a cunette, there should be a caponniere to flank it.

_Defilement_, in fortification, is the art of disposing all the works of a fortress in such a manner, that they may be commanded by the body of the place. It also includes the relative disposition of the works, and the ground within cannon shot, so that the one may be discovered, and the other not observed.

_Demi-gorge_, is half the gorge, or entrance into the bastion, not taken directly from angle to angle, where the bastion joins the curtain, but from the angle of the flank to the centre of the bastion, or rather the angle the two curtains would make were they protracted to meet in the bastion. Mr. Landmann determines it to be the line which is formed by the prolongation of the curtain meeting the oblique radius.

_Demi-lune._ See RAVELIN.

_Descents_ in fortification, are the holes, vaults, and hollow places made by undermining the ground.

_Descents into the ditch or fossé_, are boyaux or trenches effected by the means of saps in the ground of the counterscarp, under the covert way. They are covered with madriers, or hurdles, well loaded with earth, to secure them against fire. In ditches that are full of water, the descent is made even with the surface of the water; and then the ditch is filled with fagots, fast bound, and covered with earth. In dry ditches the _descent_ is carried down to the bottom; after which, traverses are made either as lodgments for the troops, or to cover the miner. When the ditch is full of water, the _descent_ must be made over its surface; which is done by securing it with blinds or chandeliers, from being enfiladed, or by directing the course of the descent from the point of enfilade in the best way you can.

_Detached bastion._ See BASTION.

_Detached redoubt._ See REDOUBT.

_Ditch_, in fortification, is a large deep trench made round each work, generally from 12 to 22 fathom broad, and 15 to 16 feet deep: the earth dug out of it serves to raise the rampart and parapet. Almost every engineer has a particular depth and breadth for ditches; some are for narrow ones and deep, others for broad ones and shallow; and it is most certain that ditches should be regulated according to the situation. In regard to wet and dry ditches, almost all authors have given it in favor of the latter; and we shall only add, that the best of all are those which can either be filled or kept dry at pleasure.

_Wet ditches_, which have stagnant waters, are liable to great inconveniences. They are said to be well calculated to prevent sudden surprises and assaults; but we are convinced of the contrary, especially during a hard frost. Some again assert, that they stop all communication between ill-disposed persons in the garrison and the besiegers. Every man with the least experience, must be of a different opinion.

Wet ditches might certainly be so constructed, as to let the surface of the water remain 12 or 15 feet above the level of the adjacent country. In which case they would serve as large reservoirs, and not only contribute to the defence of a fortified place, but enrich the grounds by being occasionally let out. The additional value which the neighboring meadows would bear from these seasonable overflowings, might in some degree compensate for the expence of the fortification. During a siege, these waters, with proper management, must give considerable uneasiness to the enemy that invests the place.

To answer this double purpose, the ditch must be separated into several large basons, which might be filled or emptied at discretion, as often as circumstances would require.

_Dry ditches._ There are some ditches which may be filled at will; and others which cannot, except by extraordinary means. If they should be intended to answer the purpose of agriculture, aqueducts might be constructed, or the waters poured in through artificial channels. In which case the ditches would not require much depth. The glacis might be raised in such a manner as to serve to dam in the body of water, and to afford a second glacis from whence the besieger might be considerably embarrassed.

_Ditches that are lined_, ditches whose counterscarp is supported, and kept up by a stone or brick wall.

_Ditches that are not lined_, whose counterscarp is supported by earth covered with sods. These ditches are not so secure as the former, on account of the breadth which must be given to the talus, and by which an enemy might easily surprise a place.

So that ditches in fortification may be briefly distinguished under three separate heads, viz:

_Dry ditches_, which from the facility with which they may be repaired, and their capability of containing other works proper for their security, are in most instances preferable to any others.

_Wet ditches_ that are always full of water, and consequently must have bridges of communication which are liable to be destroyed very frequently during a siege.

Wet ditches are subject to many inconveniences, are ill calculated to favor sallies, and have only the solitary advantage of preventing a surprise.

The third sort of ditch has all the advantages of the other two kinds; if, as we have just observed, it can be so contrived, as to admit water occasionally into the different basons by means of aqueducts, and be drained, as circumstances may require.

_Draw-bridge._ See BRIDGE.

_Embrasures._ See EMBRASURE.

_Envelope_, is a work of earth raised occasionally in the ditch, sometimes like a plain parapet, at others like a small rampart with a parapet to it. Envelopes are generally made before weak places.

_Epaulement._ See EPAULEMENT.

_Epaule_, or the shoulder of the bastion, the angle made by the union of the face and flank.

_Escarp._ See SCARP.

_Esplanade._ See ESPLANADE.

_Exterior side of a fortification_, is the distance, or imaginary line drawn from one point of the bastion to that of the next.

_Faces_ of the bastion. See BASTION.

_Faces_, of any work, in fortification, are those parts where the rampart is made, which produce an angle pointing outwards.

_Face prolonged_, that part of the line of defence rasant, which is terminated by the curtain, and the angle of the shoulder.

_Fascine._ See FASCINES.

_Fausse bray_, is a low rampart going quite round the body of the place; its height is about 3 feet above the level ground, and its parapet is about 3 or 4 fathom distant from that of the body of the place. These works are made at a very great expence: their faces are very easily enfiladed, and their flank of course is seen in reverse: the enemy is under cover the minute he becomes master of them; and a great quantity of shells which may be thrown into them, and must of necessity lodge there, will go near to make a breach, or at worst to drive every one out. Hence they are liable to do more harm than good, and contribute no way to the defence of the place. M. Vauban only makes them before the curtains, and as such calls them tenailles.

_Flanks_, in fortification, are, generally speaking, any parts of a work, which defend another work along the outsides of its parapets.