Page:Cyclopaedia, Chambers - Volume 1.djvu/826

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FORTIFICATION, call'd alfo Military Architecture, js the An of fortifying, or Strengthening a Place ; by

and Angles whereof arc generally about a Mufltet Shot from

each other. See Polygon. ,..g Works around the fame, to render it capable of being In a Regular Fortification, the Parts being all eqnal have defended by a fmall Force, againft the Attacks of a more the Advantage of being equally defcnfible ; fo that there numerous Enemy. See Military Architecture. are no weak 'Places.

Some Authors go back to theBeginning of the World, for Irregular Fortification, is that wherein the Baftions' the Author and Origin rf Military Architecture. are unequal, and unlike; or the Sides, and Angles not alt

According to them, GOD himfelf was the fitft Engeneer; and Paradice, or the Garden of Eden, the firft Fortercf/e'. Cain improv'd on the Hint, in building the firft City, Gen.fr. 17. After him came Nimrod,Gcn. x. 17. Then Semiramis, as Policcmts relates, Stratagem. L. VIII. c. 27. The Canaan- jtes, Numb. xiii. 19. 'Dent. i. 28. David, z Kings v. 9. So- lomon, 2 Cbron. iii. 5. Rehoboam his Son, 2 Chron. xi. 5, ic. and the other Kings of Jllda and Ifrael, and at length the Greeks and Romans. Vitruvius L. X. Iaft Chap, and L- 1- c. 5.

Su.h is the Series of thofe who fortify 'd Places: To which might be added Pharoah, the Perfecutor of the Ifraelites, who built the Cities of pithom and Raamfes. Exod.i. 11.

But how antient foever the furrounding of Cities with Walls, Towers, &c. may be; the Name Fortification, arid the Art now understood thereby, are of no very old Stand- ing.—

equal, and equidKtant.

In an Irregular Fortification, the Defence and Strength! being unequal ; there is a Neceflity for reducing the Irregu- lar Figure, as near as may be, to a Regular one.

And, as the Irregularity of a Figure depends on the Quantity of Angles and Sides ; the Irregularity of a Fortifi- cation arifes either from the Angles being too fmall, or the Sides being too long, or too ifiort.

Confequently, an Irregular Figure being propos'd to be fortify'd; all the Angles, with the Quantity of the Sides, muft be found, to be able to judge how it is to be fortify'd.

Durable Fortification, is that built with defign to remain a Handing Shelter for Ages. Such are the ufual For- tifications of Cities, Frontier Places, &c.

Temporary Fortification, is that erected on fome e- mergent Occafion, and for little time.

Such are Works caft up for the feizing and maintaining

They had their Rife fince the Invention of Cannons ; the a Poft, or PafTage ; thofe about Camps, &c. as Circumvalla

rrible Effects whereof render'd it neceffary to change the tions, Contravallations, Redoubts, Trenches, Batteties, &c. Structure of the antient Walls, and add fo many Things FORTIFIED "Place, a Forterefs, or Fortification; i. e. thereto, that thofe Changes were thought enough to confti- a Place well flank 'd, and fhelter'd with Works, tute a new Art, which was called Fortification, by reafon of Places fortified, after the modern way, confift chiefly of the Strength it afforded thofe in Cities, to defend them a- Baftions, and Curtains, and fometimes of Demi-Baftions $ gainit an Enemy. according to the Situation of the Ground, of Cavaliers,

The firft Authors who have wrote of Fortification, confi- Ramparts, Fauffe-brayes, Ditches, Counterfcarps, Cover & der'd as a particular form'd Art, are Ramelli, and Cataneo, Ways, Half Moons, Ravelins, Hornivorks, Croimworks, Italians. After them Errard, Engineer to Henry the Great Outivorks, Efplanades, Redents, and Tenailles. See each of France ; Stevinus, Engineer to the Prince of Orange, Ma- under its proper Article, Bastion, Curtain, Rampart, rolois, the Chevalier' <&: Ville, Lorini, the Count de Pagan, and the Marefhal de Vaitban -. Which two laft Noble Au- thots contributed very greatly to the Perfection of the Art.

From the Idea and Office of Fortification, Ibme General Fundamental Rules or Axioms may be drawn, as

i° That the Manner of fortifying ihould be accommo- dated to that of Attacking : So that no one Manner can be affured will always hold, unlefs it be affuted the Man-

Cavalier, Faussebraye, Ditci-i, Sec.

There are other moveable and additional Parts, as Ber- mes, Parapets, Banquettes, Embrasures, Cordons, Boyaux, Moulinets, Chevaux de Frife, Chausse- tr-APrs, Galleries, Mantelets, Batteries, Saps, Mines, Blinds, Gabions, and Palissades. See each in its Place.

Several of thefe Works, again, confift of divers Parts,

ner of Befieging be incapable of being alter'd ; and to judge which have different Denominations : Thus a Bafiion con-

of the Perfection of a Fortification, the Method of Eefieg- lifts of Faces, Flanks, Casemates, Orillons, Gorge,

jng at the Time when it was built, muft be confider'd. ' gffc. which fee.

2 Ali the Parts of a Fortification ihould be abletorefift The Methods of Fortifying, that have been invented,

the moll forcible Machines us'd in Befieging. are various; and new Methods continue {till to be propos'd.

3 A Fortification Should be fo contriv'd, as that it may The principal, and thofe which chiefly obtain thro' Europe,

. be defended with as few Men as poffible ; which Confidera- are thofe of Coehom; Pagan, Vauban, and Scheiter, from

tion, when well attended to, faves a world of Expence. which all the reft are eafily conceiv'd.— —

4 That the Defendents may be in the better Condition, Fortification, according to the Dutch Method, is that,

they muft not be expos'd to the Enemy's Guns and Mortars ; which making the Flank perpendicular to the Curtain,

but the Aggreffors be expos'd to theirs. makes the Flank fubduple of the Face, and fubtriple of the

Hence 5 All the Parts of a Fortification ihould be fo Curtain ; and the Angle of the Baftion, equal, either to two

difpos'd, as that they may defend each other; in order to thirds of the Angle of the Polygon; or to half thereof,

this every Part thereof is to be flank'd, i. e. capable of be- with the Addition of 1 5 or 20 Degrees, to make it equal to

in<* feen and defended from fbme other ; fo that there be no Place where an Enemy can lodge himfelf, either unfeen, or under Shelter.

6° All the Campaign around muft lie open to the Defen- dents ; fo that no Hills or Eminences muft be allow'd, behind

a right Angle.

Freitach determines the Quantity of the Flank in a fquare to be fix ; in a Pentagon, feven ; in a Hexagon, eight; in a Heptagon, nine ; in a Enneagon, ten; in a Decagon, eleven and in all other Figures, twelve Rhinla-nd Perches : Confe-

which the Enemy might jhelter himfelf from the Guns of qucntly, the Face 24, and the Curtain j<; Perches. the Fortification- or from which he might annoy them with To draix the Profile of a Fortification after the Dutch

- Draw the inner Polygon G H Tab. Fortification.

his own. j

The Fortrefs, then, is to command all the Place round

about ; confequently the Outworks muft all be lower than

the Body of the Place.

7 No Line of Defence to be above Point blank Mulket

Shot, which is about 120 Fathom.

8" The acuter the Angle at the Centre ; the Stronger is

manner ;

Fig. 6. into five equal Parts : The Demigorge A B is to contain one of them ; and the Capital A B, two. Then di- vide the Curtain E A into four Parts ; and make the Flank A B one.

This is F'reitach's Method : But the French make both the Demigorge, and Flank a fixth Patt of the Polygon^ and

the Place as confiding of the more Sides, and confequently in Squares, and Pentagons, fetting afide the fecond Flanks,

defcribe a Semicircle upon B S, that the Angle of the Ba- ftion C may be a right Angle.

The Italians giving the fame Dimenfions to the Gorge and Flank, make the fecondary Flank half the Curtain, in Polygons exceeding a Hexagon, and a third of the Curtain in the reft.

Laftly, the Spaniards giving the fame Dimenfions to the Flanks, omit the fec'undary Flanks.

But Flanks perpendicular to the Curtain, with fecundary Flanks, are in Difrepute, on account of the Obliquity of the Defence; fo that the Dutch Method of fortifying, with the other antient ones, founded on the fame Principles, are now out of Doots.

Fortification, according to the Count de Pagan s

more defenfible.

Such are the General Laws and Views of Fortification : The Particular ones, refpecting each feveral Work or Mem- ber thereof, will be deliver'd under their proper Articles.— See Fortified Place.

Fortification is alfo us'd for the Place fortified ; or the feveral Works rais'd to defend and flank it, and keep off the Enemy. .

All Fortifications confift of Lines and Angles, which have variousNames, according to their various Offices. See Line,

and Angle.

The principal Angles are thofe of the Centre, the Flank- ing Anije, Flank'd Angle, Angle of the Epaule.

The principal Lines are, thofe of Circumvallation.

of Contrav'allation, of the Capital, &c. See each Method; fuppofes in the larger Fortifications, the external

in its Place Polygon A B, Fig. 7. to be 100, the Face A G, 30 Perches ;

Fortifications are divided into Regular, and Irregular ; in the fmaller, the firft, 80, and the fecond, 25 ; and in the

and again into Durable, and Temforary. middle Size, the fitft 90, and the lecond 271 = 1 he i er-

fiegato- Fortification, is that wherein the Baftions pendicular C D, 1 5, and the Flanks O i and H h perpen-

are all equal ; or that built in a regular Polygon ; the Sides dicular to the Lines of Defence A. F and B b, cover d with