else to occupy a spot of ground which manner. The authors who have written on the subject, have never thought of this useful part; and we often see 2 horn-works put practice to cover two curtains, where crown-work would do it much cheaper || and much better. The crown-work is opted for the same purposes as the horn-work. Crowned horn-work, is a horn-work with a crown-work before it. See CROWNWORK. by the prolongation of the curtain meating 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 faggots, 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 doue by securing it with blinds or chandeliers, from being Curtain, 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 pre-enfiladed, or by directing the course of ferred to the different designs which tave been proposed, of which some have diminished the expence, and (at the same time) the strength of the pace; others have somewhat augmented the strength, but greatly diminished its area. Curette, is a small ditch from 15 Cunette, to 20 feet broad (more or less, 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 taponniere 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 comanded 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 center 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 the descent from the point of enfilade Wet ditches, which have stagnant waters, are liable to great inconveniences. They are said to be well calculated to prevent sudden surprizes 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 Ff water 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 neighbouring 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, Ditches 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 favour sallies, and have only the solitary advan tage of preventing a surprize. 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 occasionally water 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, is, properly speaking, any thing high and steep, and is used in fortification, to express the outside of the rampart of any work next to the ditch. 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 razant, which is terminated by the curtain, and the angle of the shoulder. Fascine. Sce 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 then, 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 Flanks are, generally speaking, any parts of a work, which defend another work along the outsides of its parapets. between the extremity of one flank and that of the other. Gorge, of any work, is that part next to the body of the place, where there is no rampart or parapet: that is, at the counterscarp of the ditch. Half-moon, (Fr. Demi-Lune.) Is an Flanks of the bastion, are the part between the face and the curtain; the flank of one bastion serves to defend the ditch before the curtain and face of the oppo-out-work that has two faces which form site bastion. a saliant angle, the gorge of which re Flanking, is the same thing in forti-sembles a crescent. It owes its origification, as defending. Retired flanks, are those made behind the fine which joins the extremity of the face and the curtain, towards the capital of the bastion. Concave flanks, are those which are made in the arc of a circle. Direct, or grazing flank, is that which is perpendicular to the opposite face produced, and oblique or fichant, when it makes an acute angle with that face. Second flank. When the face of a bastion produced does not meet the curtain at its extremity, but in some other point, then the part of the curtain between that point and the flank, is called the second flank. The modern engineers have rejected this method of fortifying. See FLANK. Fleche, a work of two faces, often Constructed before the glacis of a fortined place, when threatened with a siege, in order to keep the enemy as long at a distance as possible. Gallery, is a passage made under ground, leading to the mines: galleries are from 44 to 5 feet high, and about 3 or 4 feet broad; supported at top by wooden frames, with boards over them. [ Genouilliers, the undermost part of a battery, or that part from the platform to the embrasures. Glacis, is the part beyond the covert way, to which it serves as a parapet, and terminates towards the field in an easy slope at about 20 fathom distance. Sometimes double glacis are made parallel to the esplanade, and at the distance of 16, or 20 fathoms. nal invention to the Dutch, who use it to cover the points of their bastions. This kind of fortification, is, however, defective, because it is weak on its flanks. Half-moons are now called ravelins; which species of work is constructed in front of the curtain. See RAVELINS. Gorge of a half-moon, the distance between the two flanks, taken on the right of the counterscarp. Head of a work, its front next the enemy, and farthest from the place. Hornwork, is composed of a front and 2 branches: the front is made into 2 half bastions and a curtain: this work is of the nature of a crown-work, only smaller, and serves for the saine purposes. The use of horn-works in general is to take possession of some rising ground advanced from the fortification; the distance of which determines that of the horn-work; and they are placed either before the curtain, or before the bastions, according to circumstances. Horse-shoe, is a small round or oval work, with a parapet, generally made in a diteh, or in a marsh. Insult. A work is said to be insulted, when it is attacked suddenly and openly, Interior side of a fortification, an imaginary line drawn from the centre of one bastion to that of the next, or rather the curtain produced till they meet. Lodgement. See SIEGE. Loop-holes, are either square, or oblong holes, made in the wall, to fire through with musquets. They are ge inches wide within, and 2 or 3 without; so that every man may fire from them direct in front, or oblique to right or left, according to circumstances. Some authors think these works never answer the expence; however, M. Vau-nerally 8 or 9 inches long, 6 or 7 ban was so sensible of their goodness, that he never failed to make them when the ground suited; because, when such works are defended by a fkilful governor, they will afford the means of being valiantly supported. Lunettes are works made on both sides of a ravelin: one of their faces Gorge, of a bastion, is the intervais perpendicular to half or 2-3ds of the Ff2 faces faces of the ravelin, and the other nearly so to those of the bastion, There are likewise lunettes, whose faces are drawn perpendicular to those of the ravelin, within 1-3d part from the saliant angle; whose semi-gorges are only 20 fathoms. These kinds of works make a good defence, and are not very expensive; for as they are so near the ravelin, the communication with it is easy, and one cannot well be maintained till they are all three taken. Lunettes, are also works made beyond the second ditch, opposite to the places of arms: they differ from the ravelins only in their situation. placed in the covert-way, at 3 feet from, and parallel to the parapet of the glacis, to secure it from being surprised. Parapet is a part of the rampart of a work, 18 or 20 feet broad, and raised 6 or 7 feet above the rest of the rampart; it serves to cover the troops placed there to defend the work against the fire of the enemy. Parallels. See SIEGE. Port-cullice is a falling gate or door, like a harrow, hung over the gates of fortified places, and let down to keep out the enemy. Place, is commonly used in fortification instead of a fortified town. Regular place, one whose angles, breast-sides, bastion, and other parts are equal, &c. Lunettons, are small lunettes. Merlon, is that part of the work of a battery, which is between the embrasures. Orillon, is a part of the bastion near the shoulder, which serves to cover the retired flank from being seen obliquely: it is sometimes faced with stone, on the shoulder of a casemated bastion, to cover the cannon of the retired flank, and hinder them from being dismounted by the enemy's cannon. Of all the works in a fortification, there is none more capable to defend the passage of the ditch, and to destroy the miner, wheresoever he enters himself, than the orillon. Experience has shewn us of what vast advantage it is to have 2 or 3 reserve pieces of cannon, which command the ditch, and the face of the opposite bastion, in such a manner as to destroy the attempts of the miners, and see the breach in reverse. Hence the great advantages of a double flank thus concealed weigh so very much with us, and convince us so entirely of their usefulness, that we affirm no place to be well fortified without the orillon, and that the straight flank is fit for nothing but fieldworks. The orillon is as old as the bastion, and was first made use of about the year 1480; and we find it frequently mentioned in the works of Pasino and Speckle, first published in 1579. Out-works, See WORKS. Palisades are a kind of stakes made of strong split wood about 9 feet long, fixed 3 deep in the ground, in rows about 6 inches asunder: they are Irregular place, one whose sides and angles are unequal, &c. Place of arms, is a part of the covert-way, opposite to the re-entering angle of the counterscarp, projecting outward in an angle. It is generally 20 fathoms from the re-entering angle of the ditch on both sides, and the faces are found by describing a radius of 25 fathoms. Places of arms. See SIEGE. Pits, or ponds, are little holes dug between the higher and lower curtains, to hold water, in order to prevent the paffing from the tenailles to the flanks. Profiles are representations of the vertical sections of a work; and serve to shew those dimensions which cannot be described in plans, and are yet necessary in the building of a fortification: they may be very well executed and constructed upon a scale of 30 feet to an inch. By a profile are expressed the several heights, widths, and thicknesses, such as they would appear were the works cut down perpendicularly from the top to the bottom. Rampart, is an clevation of earth raised along the faces of any work, 10 or 15 feet high, to cover the inner part of that work against the fire of an ene my: its breadth differs according to the several systems upon which it may be constructed: for De Ville makes them 124 fathoms, M. Vauban 6, and others 10 fathoms. Rams-horns, in fortification, are a kind of low work made in the ditch, of a circular arc; they were first invented by M. Belidor, and serve instead of tenailles. Ravelin, in fortification, is a work placed before the curtain to cover it, and prevent the flanks from being discovered sideways: it consists of 2 faces meeting in an outward angle. Some ravelins are counterguarded, which renders them as serviceable as either the cunettes, or tenaillons. Gorge of a racelin, is the distance between the two sides or faces towards the place. Gorges, of all other out-works, are the interval, or spaces which lie between their several wings or sides towards the main ditch. See GORGES. Redans, in fortification, are indented works, consisting of lines or facings that form sallying or re-entering angles, flanking one another, and are generally used on the sides of a river nning through a garrisoned town. They were used before bastions. Some tres the parapet of the covert-way is carried on in this manner. Redoubt, is a kind of work placed beyond the glacis, and is of various forms. Its parapet, not being intended to resist cannon, is only 8 or 9 feet thick, with 2 or 3 banquettes. The length of the sides may be from 10 to 20 fathoms. Redoubt, is also the name of a small work, made sometimes in a bastion, and sometimes in a ravelin, of the same form. Redoubt, is likewise a square work without any bastions, placed at some distance from a fortification, to guard a pass, or to prevent an enemy from proaching that way. ар Detached-redoubt, is a kind of work much like a ravelin, with flanks placed beyond the glacis: It is made to occupy some spot of ground which might be advantageous to the besiegers; likewise to oblige the enemy to open their trenches farther off than they would otherwise do. Their distance from the covert-way should not exceed 120 toises, that it may be defended by musket-shot from thence. Redouts-en cremaillere, so called from their similitude to a pot-hook; the in side line of the parapet being broken in such a manner, as to resemble the teeth of a saw; whereby this advantage is gained, that a greater fire can be brought to bear upon the defilé, than if only a simple face was opposed to it, and consequently the passage is rendered more difficult. Retrenchment is any work raised to cover a post, and fortify it against an enemy; such as fascines loaded with earth, gabions, sand-bags, &c. Revetement is a strong wall built on the outside of the rampart and parapet, to support the earth, and prevent its rolling into the ditch. When the revetement of a rampart goes quite up to the top, 4 feet of the upper part is a vertical wall of 3 feet thick, with a square stone at the top of it, projecting about 5 or 6 inches, and a circular one below, or where the slope begins, of 8 or 10 inches diameter. They go quite round the rampart, and the circular projection is called the cordon. Rideau is a small elevation of earth, extending lengthways on a plane, and serving to cover a camp, or to give an advantage to a post. They are also convenient for the besiegers of a place, as they serve to secure the workmen in their approaches to the foot of a fortress. Rideau is also used sometimes for a trench, the earth of which is thrown up on its sides, to serve as a parapet for covering the men. Sap. See SIEGE. Sillon, a work raised in the middie of a ditch to defend it when too broad. This work has no particular construction, but as it runs, forms little bastions, half-moons, and redans, which are lower than the rampart of the place, but higher than the covert-way. It is not much used at present. Sillon means literally a furrow. In fortification, it is a work raised. Swallow's-tail, a kind of out-work, only differing from a single tenaille, in that its sides are not parallel as those of the tenaille, but narrower towards the town than towards the country. Talus signifies a slope made either on the outside or inside of any work, to prevent the earth's rolling down; it is of various denominations, viz. Talus |