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item in estimating the resisting power of a work, as it nature of the missiles agaiust which the parapet is represents the vertical equivalent of the obstacle to afford protection. For example, an earth work of which will be offered to a foe.
from three to four feet suffices to resist musketry; a When the relief of the parapet's crest has been thickness of 18 feet is inpervious to the 24-pounder; determined, its thickness becomes the next con- while larger guns can pound through even more sideration. The dimensions are laid down on the solid obstructions. ground, and depend, first, on the angle at which the Taking fig. 7 as an example, in which a is the material to be used will pile; and then, on the crest of the parapet, then the banquette c should,
for convenient firing, be four feet three inches | glacis, as, otherwise, an assailant having reached the below a; its width three feet, if for a single line latter, would be able to pour a musketry-tire over of soliliers ; four feet six inches for a double rank; the former into the work. No part of any glacia, its slope should be one in twelve, that water may whether near or advanced, should be more than run freely otr. The base, be, of the slope, up two feet below the line of fire from the parapetwhich the men mount to the banqnette, should i. e., the line joining the crests of the parapet and be twice its height 'bc, and cut into steps with glacis continued ; if more depth be allowel, the inclined sides, to allow of easy ascent; and where enemy may advance in a crouching posture, without the height is considerable, à supplemental ban- being liable to be hit. Advanced glacis are usually quette (on which relieving.men can, if necessary, madle of earth thrown up in prolonging beneath the reloail), is desirable. The interior slope, ac, of ground the plane of the preceding glacis. They the parapet shonkl be one in four; the exterior may be defended entirely from the parapet, in slope, or plongée, ail, intended for the direction of which case palisades or abattis are often fixed (as in thu guns on an assailant, one in six, a deviation tig: 7) to delay the advancing enemy when at the being permitteil between one in nive and one in point of greatest exposure.
On the other hand, four; but the crest being more liable to destruction these advanced glacis are occasionally defender as as the slope of all is augmented, it is best to keep a series of advanced intrenchments, and only it as small as circumstances will allow ; one in six abandoned, one by one, as the defenders are driven is the orilinary slope in English fortification, the in towards their main work. angle of the interior slope being constant. In some The dimensions of the dit :h slepend in some continental services, however, the angle, cal, is kept measure on the amount of earth required for the constant at 100°, by increasing the deviation of the parapet and glacis ; but in addition to being the interior slope of the prapet from the perpendicular mine whence the materials for the latter works as the plunge of the exterior is greater. The flatter, are drawn, the ditch must also oppose a consider however, the crest of the parapet is the better, as able obstacle to any hostile advance. To do this sanıl-bags are in certain cases ranged on it to form effectually, the minimum width across the top is cover for the men, while they fire through loopholes 18 feet; its depth need only be limited by the left in this aditional defence. Earth of medium trouble of raising the earth ; but in practice 12 tenacity maintains its position properly when sloped fcet is found the greatest which can be conveniently at an angle of 45°; and this is the greatest angle arrived at. Having ascertained the protile of the which can be counted on for the outer slope of the parapet, with its banquette or banquettes, bonnets, parapet. The scarp, l, and counterscarp, in, of the traverses, glacis, &c., it becomes a mere matter of diteh need not have so great an incline, as the mensuration to compute the area rof a £ection, to grounil in wlich they are cut has usually had time, multiply it by the length, and so to obtain the and the footsteps of ages, to consolidate it. In such cubic feet of earth required. With the length of cases, the base of the triangle is frequently made the ditch known, a very simple calculation then equal to half the perpendicular. Cases, of course, exhibits its width and depth -a smal allowance occur in which steeper bauks are considerel indis- being made for the fact that the earth, lus out from pensable; and then, to prevent slips, the earth must the ditch, where it has probably been long comhave a coating to keep it up, which may be of pressed, will occupy somewhat more space when fascines, hurilles, planks, or sand-bags, for temporary thrown up, and broken into clods, for forming the works, or those constructed in the midst of action; parapet. while the most solid masonry performs the same The scarp, or inner face of the ditch, is most function in fortresses of a more permanent nature. difficult of ascent by the assailant, when in a conThis outer coating is denominated a revêtement. tinuons line with the parapet (as in tig. 7); but
In tig. 7, ghi, is the glacis, formed during the sometimes it would be dangerous to construct the oxcavation of the ditch, and having for object the work with this continuity, as dumage to the scarp buging of an aulvancing enemy into the best line of would jeoparilize the stability of the parapet. In fire froin the parapet. The base and perpendicular these cases a narrow step, called a Berm (4. v.), of of its interior slope, gh, should be equal; the slope of from two to four feet, is male to intervene between the outer face should be one in twelve, unless the the foot of the parapet and top of the searp; as a Bloj e of the ground render some different angle precaution, it is covered with all possible obstacles desirable. An alvanced glacis, k in fig. 7, is some to any lodgment being effected on it by the enemy. times adopted, in oriler that the enemy may the When a berm is employed, greater steepuess is usually Booner be brought under fire, It is absolutely given to the scarp. 06cessary that the crest of the parapet should be The counterscarp, or outer sloping side of the five and a half feet higher than the crest of the ditch, should be somewhat steeper thun the sammu
The bottom of the ditch should slope from both higher inan the general interior, with a view to sides towards the centre, to carry off the water ; guns being fired from it over the parapet. and obstacles should be scattered about to prevent There are certain fixed rules in all fortification, an enemy from forining his troops in the ditch. such as :-1. The length of linus must never exceed
EarruwORKS IN FIELD Fortification.--As the musketry range, or the Hankiug works would become most readily constructed, earthworks naturally ineffective for their object. 2. The angles of defence recoinmend themselves to the engineer, who, in should be about right angles. 3. Salient angles the tield, is called upon to defend the position of should be as obtuse as possible. 4. Ditches should an army against sudden attack. Their utility has have the best possible Hanking. 5. The relief of the been shewn in their employment from the earliest Hanking-works must be determined by the length tines, and modern experience tends to prove that of the lines of defence. 6. The value of almost earth-parapets are of all fortitications among the every detached work depends on the support it can most difficult to overcome. An army manæuvring give to or receive from an army or other work or before a superior force, can scarcely hope to avoid works. 7. The reduction of every fortified work battle being thrust upon it, unless, strengthened is merely a question of time; and a work fairly by fiellworks, it be rendered more nearly equal surrounded is sure to fall, unless relieved from to the adversary. Napoleon, Marlborough, Eugène, without Wellington, have given their names as witnesses to Fieldworks, which, it must be borne in micd, are the indispensability of such works. The Russian intended merely to support or strengthen an arıny, parapets at Borolino niale the French victory so may either have a complete circuit of parapets, or Banguinary a triumph that it was useless to the may be open at the gorge in the rear. The latter victors. A few redoubts at Pultowa savedl Peter are, of course, the simplest; but the Great from_total defeat by his formidable they are only available in posiSwedish rival. The world-famed lines of Torres tions which the enemy cannot Vedras enabled Wellington with 50,000 troops, half turn, or where protected by the of whom were intried Portuguese, to withstand for sweeping fire of other works five months, and ultimately to drive back, the behind. Of this class the Relan, hitherto victorious army of 70,000 French, under a mere salient angle (see tig. 9), Fig. 9.-Redan. such commanders as Masséna, Ney, and Junôt. is the simplest and the repres The earth works surrounding Sevastopol partook sentative form. Of the closell forts, there are greatly of the nature of fieldworks for the protec. Redoubts, usually sqnare; Stur-forts, now considered tion oi a large army, and history will not forget to objectionable ; bastioned forts, as in lig. 10, which recunnt the resistance they oflered for almost a tank their own ditches almost perfectly, while year to the best troops of the civilised world. scarcely susceptible of
For a line, whether of earth or masonry, to be being tanked them. efficient, it niust conibine artillery fire with that of selves. To under musketry. The guns will generally be so placed as stand the nature of to command some specific line of approach, such as a single bastion, see a ravine, a line of abattis, or some portion of the A (fig. 10), which glacis. They should themselves be as little exposel represents one at the as possible, nor should the gunners be uncovered corner of a square more than is absolutely requisite. To effect this, work; ab is the left the gun is generally maile to tire through an embra- slank, bc the left face, sure (q. v.) in the parapet, insteiul of over the latter. cd the right fuce, de The embrasure is a cutting through the solid para: the right slank ; ae is pet, 20 inches wide at its inner extremity, and the gorge; af, fe are outwarıls half as much as the width of the parapet. the demi-gorjes, being
Fig. 10.–Bastioned Fort. In cases where it is necessary, for proper command, continuations of the that the line of tire should not be lower than the sides, or curtains, of the work; a and e are the top of the parapet, the embrasure is made through left and right curtain angles ; b and d, the left and an auditional parapet-raiseil, as in the previous right shoulder angles, and c is the plunked anyle. case of the bonnet, above the original one. The Continuel lines are simple parapets, either con. bottom of the embrasure is called the sole, and necting fortified posts, or covering the front or llank slopes downward sutliciently to allow of a certain of an ariny.
Reclans depression being given to the gun. The remainder joined by curtains (as in of a parapet below the sole is the genouillerè (from fig. ll) are those most genou, a knee), and in fiell fortitication should be easily constructed ; but Fig. 11-Continued line of three and a half feet high; the portion between as the ditches can ouly be
Redans, two embrasıires is the merlin (Ital. nerlune, battle. defended by an oblique ment); and an enbrasure neerl not cut the parapet tire, the curtains are occasionally so broken as to perpendicularly, an angle being admissible, when form nearly right angles with the faces of the in obliquo fire is necessary. When, however, the redlan, as in the dotted line; they then become
obliquity would lines of tenailles.
form a project
ing angle in it, tarough which the embrasure is cut (as in fig. 8).
Fig. 12-Line with intervals. The si les of the embrasures are cheeks, and require revating
as effective as continued lines. They consista A barbelte is a platform raised behind a parapet, | detached works, in two lines, within musketry
fire of each other. The re-entering angle, abc (fig. emperor to the introduction of cannon for breaching 12), should as nearly as practicable be a right purposes. Then the square and round towers, which angle. The celebrated lines of Torres Vedras, before had formed sutticient tlanking defence against adverted to, consisted of 150 detached forts. arrows, proved useless when cannon-balls, fired from
7'ête-du-pont, is a work constructed to cover the a distance, were the instruments of assault At the approaches to a bridge, and will be found described same time, the walls, which had resisted battering, under BRIDGE-HEAD.
rams, crumbled to atoms under the strukes of A tenaille is the reverse of a redan, and consists of artillery. two faces forming a re-entering angle: it can only Fortunately, however, the art of defence has be used in connection with some other work. always made equal progress with that of attack;
A flèche is a breastwork of two faces, forming aand, early in the 15th, if not late in the 14tb C salient angle, constructed on the exterior of a glacis, the Italians had commenced to flank their walls usually at its foot, in order to defend the ground with sınall bastions. The bastions at Verona, bruilt before a bastion or ravelin.
by Micheli in 1523, are usually looked upon as the Having now explained the principal forms which oldest extant specimen of modern fortification elemental works of fortification are made to assume, Tartaglia and Albert Dürer, painter and engineer, ve proceed to describe— very briefly, of course— were early in the field In most of the earlier systems the systems into which these have been incorpor. the face of the bastion was perpendicular to its flank. ated for the defence of fortresses, towns, and other The first principles were successively in proveel by permanent purposes. It will merely be necessary Marchi, an Italian, who died 1599, by Errarl Boisto state, in addition to what has been already le-Duc, and De Ville, under Henry IV. and Louis written, that a rampart is a raised structure of XIII. of France. The Count de Pagan, whose earth or stone, above the mean level of the country, treatise appeared in 1645, did much towarls demol. on which the parapets, &c., can be thrown up, and ishing previous errors, and laid the basement of that which affords to the town or space protected the science which Vauban subsequently wrought almost extra cover of its height, while it elevates the to perfection. Born in 1633, Vauban haul a genius inner works sufficiently to enable them to command which penetrated in every direction, equally in the and fire over those situated exteriorly to themselves. ways of war and in those of peace. He might juos. It need scarcely be said that a line which can be sibly have taught how fortresses could be rendered made of earth may equally be constructed of any impregnable, haul not the restless ambition of his other material which circumstances may render master, Louis XIV., led hiin to demonstrate, first. desirable, the maximum resistance and minimum that the reduction of any work was a mere question liability to splinter being the qualities to be chiefly of time and powder. His talent so improved the considered.
system of attack, that even he himself could not SYSTEMATIC FORTIFICATION FOR PERMANENT construct a rampart that shouid withstand the fire WORKS. — Adverting to the most ancient fortifica- conjured up against it by his discoveries. He contions mentioned in history, we find Greek cities structed 33 new fortresses, improved above 100, and surrounded with walls of brick and rubble, and occa- conducted personally more than 50 sieges. To sionally of stone in huge blocks. Babylon had a him are soldiers indebted for the sweeping fire of wall of prodigious circuit—100 feet high, 32 feet ricochet, and to him in a degree for the traverses thick, and surmounted by towers. Jerusalem, at the which endeavour to render it harmless. Coeboorn, time of Vespasian's siege, had similar walls with director-general of the fortresses of the United masonry of enormous solidity. These seem to repre- Provinces, was the contemporary, rival, and opponent rent fortitication as it stood from the time of that of Vauban ; his master-piece is Bergen-op-Zoom.
Fig. 13.-Vauban's First System ; Ground-plan :
1, re-entering place of arms; K, glucis.
yarıls. Irrespective of irregularities in the form of the Vauban's first system is shewn in fig. 13 as regards place to be defended, a particular polygon is selected the outline of its ground-plan; fig. 14 displaying the is that on which the lines of defence are to be same in profile.
In this instance, the polygon taken is an octagon. tively mark off ad, bg, each equal to 2-7 ab, for the Let ab (fig. 13) be a side of this polygon; bisect faces of the bastions. Next, from a and 6 as centres this in c, and draw a perpendicular to ab. On this, with radius, ay, describe arcs cutting aC, 6C, pro inwards, mark off c one-sixth of ab; join al', 6C, duced in s and e; join de, fy, for the flanks of and produce the lines ; then from a and b respec- bastions, and ef for the curtain of the work. TL
first line of defence is then complete, the necessary faces of the bastions and the curtain command mor parapets, &c., being of course raised on the site laid or less the entire front, while the bastion flanks sweef out. From an examination of this, it will be seen along the faces of adjoining bastions and along the that the whole space in the front is covered. The curtain. In front, however, of the apex of each
Castind, the line of advance is only covered by an the same time, forms an outwork capable of assist extremely oblique fire. To obviate this, a ravelin, ing in the general scheme of defence. To trace tho F, is constructed on the further side of the main main ditch, describe from the flanked angle of the diteh, which coinmands the doubtful fronts, and, at bastion, a or b, an arc with radius 30 yards (if dry
litch, 26 if wet), and from these arcs draw tangents that the striking case and fluency of Ariosto,
FORTROʻSE, or FORTROSS, a parliamentary the inner side of the covert-way-10 yards wide east of Ross-shire, on the west side of the Moray -bel ind the glacis, which last slopes gradually birth, opposite Fort George, ten miles north-north towarıls the country, and is ordinarily the outer east of Inverness. Pop. (1871) 911. It unites with work of all. The tenaille is a comparatively low Inverness, Forres, and Nairn in sending a member parapet sweeping the depressed interior of the ravelin, to parliament. F. had a fine cathelral and a and commanded by the bastions and curtain.
bishop's palace ; but both of these buildings were The caponier, forming a communication between partially destroyed under Cromwell, and the stones the tenaille and the ravelin, consists of a passage sent to Inverness, to be used in building a fort there. between two low parapets, each with a glacis It has a good trade in various kinds of produce, as sloping towards the ditch, which is swept from the pork, eggs, all sorts of grain, and potatoes. In the work. Nine feet clear are allowed round the traverses to have been the seat of arts, science, and divinity
16th c., F. had a considerable trade, and is said on the covert-way; at the re-entering angles of the in the north of Scotland. Chanonry, with which covert-way, places of arms are formed by setting off it was united in 1444, was formerly the see of the 30 yarıls on each side, and with this as gorge, bishops of Ross. advancing faces inclined to each other at 100%. If the polygon haul been a square, cC would have been
FO'RTS AND FORTALICES. The military ab; if a pentagon, 4 ab; and for any polygon of power of the state is intrusted by the constitution more si les than seven, i ab.
of this country to the sovereign. After having been Vauluun's second and third systems were those in in the time of Charles I., it was again vindicateul for
unconstitutionally claimed by the Long Parliament which he alapted old walls to his modern improve the crown by 2 Car. II. c. 6. This branch of the
Availing himself of the works already formei, lie aldent counterguards in front of the royal prerogative extends not only to the raising of corner-towers, thereby making hollow bastions, and armies and the construction of fleets, but to the avoiding the necessity of entirely rebuilding,
building of forts and other places of strength. Sir Cochoorn's system had counterguards in front of Elward Coke lays it down (1 Inst. 5), that no subject the bastions and parallel to them. The Hanked the licence of the king; and it was enacted by 11
can build a house of strength embattled without angle of his ravelin had a fixed value- viz., 70°.
Cormontaigne widened the gorge of his ravelin, Henry VII. c. 18, that no such place of strength thereby reducing the length of the bastion face could be conveyed without a special grant. available for breaching from without. He also FORTU'NA, called by the Greeks, Tyche, was revived the step-like formation of the covered way, in classical mythology the Goddess of Chance. origivally seen in Speckle in the 16th c., and which According to Hesiod, she was a daughter of gires defenders a continued line of fire from each Oceamus; according to Pin-lar, a sister of the Parcæ. traverse along the covert-way.
She differed from Destiny or Fate, in so far that The modern system differs but little from that of she worked without law, giving or taking away at Cormontaigne. The re-entering places of arms have her own good pleasure, and dispensing joy or circular fronts instead of angular; the angle of the sorrow indifferently. She had temples at Smyrna, ravelin is fixed at 60, and all the best points of older Corinth, and Elis. In Italy, she was extensively styles are associated.
worshipped from a very early period; and harl many Fig. 15 is intended to present at one view a repre- names, such as Patricia, Plebein, Equestris, Virilis, sertation of the systenis in force since artillery Primigenia, Pulilica, Privata, Muliebris
, cr.me into common use, as well as the gradual etc., indicating the extent and also the minuteness of transition from square towers on castle walls to her superintendence. Particular honours were paid lanked bustions on modern lines. The elements of to her at Antium and Præneste; in thc temple of the fortifying against shipping will be found unde
former city, two statues of her were even consulted MARINE FORTIFICATION ; the principles of attack- as oracles. Greek poets and sculptors generally ing fortresses generally, under SIEGE, and MINES, represented her with a rudder, as a symbol of her MIS.JTARY.
guiding power; or with a ball, or wheel, or wings, FORTIGUE'RRA, Nicolo, an Italian poet, was
as a symbol of her mutability. The Romans proudly born at Pistoja, November 7, 1674. Destined from affirmed that when she entered their city, she threw youth for the church, he proceeded to Rome at an away, her globe, and put off her wings and shoes, early perioul, where the power of the prelute Carlo to 'adicate that she meant to dwell with them for A. Fabroni, who was his relative, speedily secured him alvancement, and where he was ultimately
FORTUNATE ISLANDS. See CANARIES. raised to the dignity of prelate and papal cham. FORTUNA'TUS is the title of one of the best berlain by Clement XI. Án ardent cultivator and people's books (Volksbücher), ever written.
It protector of letters, it must be owned that F.'s own originated about the middle of the 15th c., though compositions are more prized for a certain rich many of the tales and legends included in it are of joviality of imagery, and profuse facility of language, much older date. The opinion that it was worked than for any salient beauty of style or conception, up into German from a Spanish or English original His chief work, Il Ricciardetto, was originally com- may be considered as set aside. The substance of menced in confutation of friends, who maintained the book is that F., and his sons after him, are the