Billeder på siden
PDF
ePub
[graphic]

Published by & Kearsley Fleet Street March 1182.

[ocr errors]

When a harbour is formed by a cluster of islands, it is easily fortified, if the channel between the islands is not too wide for the cannon from one or both shores; but if it be too wide, the shipping that rides there must be defended from the batteries on the shore. When the harbour lies in an inlet, or river, some miles above its mouth, a fort built at each point of the entrance, when the passage les strait, and can be commanded from side to sice, and two others between them and the harbour, but not directly opposite, unless the breadth of the channel requires it, will be a proper security for the shipping in such a harbour; and if the chanel or river is winding, the forts should be built where they can command a reach at least, or be so placed at the bends, as to command two adjacent reaches. See Robertson's Treat. of Marine Fort part ii.

Durable Fortification, is that built with design to remain a standing shelter for ages. Such are the usal fortifications of cities, frontier places, &c. Temporary Fortification, is that erected on some emergent occasion, and only for a little time.

Such are field-works, cast up for the seizing and maintaining a post, or passage; those about cups, &c. as circumvallations, contravallations, bts, trenches, batteries, &c.

There are many modes of fortification that have been much esteemed and used; a small specimen of a comparative view of the principal of these is represented in plate 73, viz. those of count Pagan, and Mess. Vauban, Coehorn, Belidor, and Blondel; the explanation of which is as follows: 1. Pagan's System.

[blocks in formation]

R Detached redoubt. S An arrow.

P Small traverses.

5. Blondel's System.

I Retired battery.

m Lunettes.

n Ravelin, with retired bastion.
o Orillons.

Another, or new method of fortification, has lately been proposed by M. Montalambert, called Fortification Perpendiculaire, because the faces of the works are made by a series of lines running in a zig-zag, perpendicular to one another.

Profile of Fortification, is a representation of a vertical section of a work, serving to shew those dimensions which cannot be represented in plans, and are necessary in the building of a fortification. This profile is constructed in the following manner: provide a scale of equal parts, adapted to the perpendicular height of the work, e. gr. let a, b, Pl. 72. fig. 3, be a scale of twenty toises; and let AB represent the level of the ground plane, so that those parts of the fortification which are above the surface of the ground, or below it, may be above or below this line in the profile. From the point A in the line AB, take AC-4 toises three feet, for the interior, talus or slope of the rampart; at C erect a perpendicular CD of three toises eighteen feet for the height of the rampart; through the point D draw an indefinite line DN parallel to AB, in which take DE=5 toises for the breadth of the terre-plein of the rampart: at the point E erect the perpendicular EF-2 feet for the height of the banquette, and draw FH parallel to DN, making FG and GH, each equal to three feet. Draw the line EG, which will represent the talus of the banquette, and GH will be the upper part of it: on the point H erect the perpendicular HI-4 feet for the height of the parapet above the banquette. From I draw the indefinite line IK, parallel to DN, in which take IL-1foot, and draw HL, which will be the interior side of the parapet: take LK toises for the thickness of the parapet, and trom the point K let fall the indefinite line KP, perpendicular to the line AB, and produce it below AB: in this line take KM-2 feet, and draw the line LM for the upper part of the parapet which is a talus, that the soldier on the banquette may be able to discover the covertway and the glacis. On the point N, where DN intersects KP, as a center, with a radius of one foot, describe a small semi-circle, which represents the cordon take NP toises, and from the point P draw an indefinite line Pn parallel to AB, which will represent the bottom of the ditch, the depth of which is supposed to be equal to the height of the rampart. Take NO=5 feet for the thickness of the revetement of the cordon, and from the point O draw the indefinite line OQ parallel to NP; this will be the interior side of the revetement of the point P, where the line Pn meets the line NP; take PR-7 feet, or about the fifth part of its height NP, for the talus of the revetement, and draw the line NR, which represents the scarp or exterior side of the revetement; take RS-1 foot for the jutting of the foundation, and draw ST perpendicular to Pn, making equal to two or three toises for the depth of the foundation, draw T2 parallel to Pn, and let it intersect 02 in 2; and let Y& be drawn parallel to NM, and at the distance of three feet, for the revetement of the parapet. In order to represent the

[ocr errors]

poule of the counterfort or buttress, when there Is any, take OV=9 feet, and draw VX parallel to OQ; VX, QO, will represent this profile, by means of which the revetement OR is strengthened. That the terre-plein of the rampart may have a proper declivity, for carrying away the water which falls upon it, let DW be equal

to 1 foot, and draw WE, which will represent the upper part of the rampart, and the line AW represents the slope of its interior side. Suppose the breadth of the ditch to be twenty toises, and lay this down from P to n; and on the point n erect the perpendicular nm, terminated by the line AB at m, which will be the limit of the counterscarp. At the distance of three feet from this line, and parallel to it, draw zy, which will give the thickness of the revetement of the counterscarp; nu=3 feet will be the talus of this re

vetement, and the line um the exterior side of it. The foundation may be made to terminate at the distance of about six inches from the point u. Let me 5 toises be the breadth of the covert

way, and at the point c erect a perpendicular cd =2 feet for the height of the banquette. Draw df parallel to AB, and equal to one toise, in which take de and ef, each equal to three feet.

Draw the line ce for the talus of the banquette, and ef will be the upper part of it: from the point f erect a perpendicular fl=4 feet for the height of the parapet of the covert-way above the banquette. Produce fl till it cuts AB in r; take rg=20 toises for the breadth of the glacis; and draw lg, which will represent the glacis, or the declivity of the rampart of the covert-way: in this line take lh= 1 foot, and draw hf, which will be the interior side of the parapet of the covert-way; after which let there be a palisade constructed on the banquette, and the profile is finished.

Other profiles are given in Plate 73, fig. 2.

FORTIFIER. s. (from fortify.) 1. One who erects works of defence (Carcw). 2. One who supports or secures (Sidney).

To FORTIFY. v. a. (fortifier, French.) 1. To strengthen against attacks by walls or works (Shakspeare), 2. To confirm; to encourage (Sidney). 3. To fix, to establish in resolution (Locke).

To FORTIFY. v. n. To raise strong places.. FORTILA'GE. s. (from fort.) A little fort; a blockhouse (Spenser).

FORTIN. s. (French.) A little fort, whose flanked angles are generally 120 fathoms distent from one another.

FORTISSIMO, in music, very loud or

strong.

FORTITUDE, a virtue or quality of the mind, generally considered as the same with courage, though in a more accurate view they seem to be distinguishable. Courage may be a virtue or a vice, according to circumstances; fortitude is always a virtue: we speak of desperate courage, but not of desperate fortitude. A contempt or neglect of danger, without regard to consequences, may be called courage; and this some brutes have as well as we: in them it is the effect of natural instinct chiefly; in man it depends partly on habit, partly on strength of nerves, and partly on want of consideration. But fortitude is the virtue of a rational and considerate mind, and is founded in

a sense of honour and a regard to duty. There may be courage in fighting a duel, though that folly is more frequently the effect of cowardice: there may be courage in an act of piracy or robbery; but there can be no fortitude in perpetrating a crime. Fortitude implies a love of equity and of public good; for, as Plato and Cicero observe, courage exerted for a selfish purpose, or without a regard to justice, ought to be called audacity rather than fortitude. This virtue takes different names, according as it acts in opposition to different sorts of evil; but some of those names are applied with considerable latitude. With respect to danger in general, fortitude may be termed intrepidity; with respect to the dangers of war, valour; with respect to pain of body or distress of mind, patience; with respect to labour, activity; with respect to injury, forbearance; with respect to our condition in general, magnanimity. The motives to fortitude are many and powerful. This virtue tends greatly to the happiness of the individual, by giving composure and presence of mind, and keeping the other passions in due subordination.

FOʻRTLET. s. (from fort.) A little fort. FORTNIGHT. s. (contracted from fourteen night.) The space of two weeks (Bacon). FORTRESS. s. (forteresse, French.) A strong hold; a fortified place (Loche).

FORTROSE, a borough in Ross-shire, situate on the Frith of Murray, nearly opposite Fort George, and nine miles W. of Taverness.

FORTUITOUS. a. (fortuit, French; fortuitus, Latin.) Accidental; casual (Ray). FORTUITOUSLY. ad. Accidentally; casually; by chance (Rogers).

FORTUITOUSNESS. s. (from fortuitous.) Accident; chance; hit.

The

FORTUNA, daughter of Oceanus, according to Homer, or one of the Parcæ according to Pindar, was the goddess of fortune, and from her hand were derived riches and poverty, pleasures and misfortunes, blessings and pains. She was worshipped in different parts of Greece. Bupalus was the first who made a statue of Fortune for the people of Smyrna, and he represented her with the polar star upon her head, and the horn of plenty in her hand. Romans paid particular attention to the goddess of Fortune, and had no less than eight different temples erected to her honour in their city. Tullus Hostilius was the first who built her 1 temple. Her most famous temple in Italy was at Antium. She was worshipped among the Romans under different names, such as Female Fortune, Virile Fortune, Equestrian, Peaceful, Virgin, &c. The goddess is generally represented blindfolded, and holds a wheel in her hand as an emblem of her inconstancy. Sometimes she appears with wings.

FORTUNATE. a. (fortunatus, Laiin.) Lucky; happy; successful (Dryden).

FORTUNATE ISLANDS, in ancient geogra phy, certain islands concerning the situation of which authors are not agreed. They were famous for the golden apples of the Hesperides.

[merged small][merged small][graphic][subsumed][subsumed][merged small][subsumed][subsumed][merged small][merged small][merged small][merged small][subsumed][subsumed][merged small][subsumed][merged small][merged small]

Profile of the Body of the Place & the Ravelin with Revetement.

ཋས་

341

Profile of the Body of the Place & Ravelin with demi Revetement.

[blocks in formation]
« ForrigeFortsæt »