FOR
481
FOR
FORTIFICATION , may be defined the science of militaryarchitecture ; ami when applied to a city, town, or other place, itconsists in the art of putting any of these in such a posture of proparation by means of ramparts, parapets, ditches, and outworks,that eacli individual part defends, and is defended by, some otherparts, so that a small number of men within may be able to detend jthemselves, lor a considerable time, against the assaults of a nu-merous army without. The origin of fortification is doubtless tohe ascribed to that rapacious principle, which has influenced toomany of mankind in all ages and nations, to invade the rights andproperties of those whom they considered as weak or defenceless.In the lirst ages of the world, men were dispersed over the earthin separate families, as is recorded in the patriarchal histories ofthe Jews and Scythians , who wandered from place to place, insearch of pasture for their cattle. These families became so nu-merous as to form large communities, which settled all together inone place; from whence villages and towns had their origin: butthey found it necessary, for the common security, to surroundthose towns with walls and ditches, to prevent all violences andsudden surprises from their neighbours. This was sutlicicnt forsome lime, till offensive weapons were invented, and conqueringbecame a fashion. Then walls with loop-holes were made at pro-per distances, in order to screen the defenders against the arrowsof the assailants: but finding that, as soon as the enemy got onceclose to the walls, they could from no part be discovered or re-pulsed ; for this reason they added square lowers at proper dis-tances from each other, so that every part of the wall might bedefended by the adjacent sides of the towers. H owever, this man-ner of the inclosing of towns was found to be imperfect, becausethere remained still one of the faces of the towers winch frontedfhe field that could not be seen from any other part, and there-fore could not be defended. To remedy this, they made thetowers round instead of square, imagining this figure to be thestrongest to resist the battering engines, as well as to be better de-moded from the other parts of the wall. Notwithstanding thesuperiority of this method above the former, there still remained aPart of these towers unseen and incapable of being defended ;''’hich made them change the figure of the towers again; i. e.‘hey made them square as before ; but, instead of presenting a faceto the field as formerly, they presented an angle ; and thus theyoifectually found out such a disposition of their works, that nopart could be attacked without being seen or defended from some°ther part. This last method was iong in use, and would in allprobability have continued to this day, if gun-powder had notbeen invented: but the violence of the guns and mortars soonconvinced the world, that such towers and walls were but a weakdefence against these thundering engines; and that, as the na-‘Ure of the attack was entirely changed, it was also necessary tochange the mode of defence. Ramparts were therefore added tobe walls; the towers eidarged into bastions, and all sorts of out-' v '°rks have been since added ; such as ravelins, counlerguards,*°rn and crown works, and others of the like nature, to render the^efence in solne measure equivalent to the attack. But in spiteall the improvements which have been made in trie art of tor-J-J.b'g) since the invention of gunpowder, that ot attacking is, U1 superior to it : engineers have tried in vain to render the ad-jutages of fortification equal to those of the attack; the supe-oritv of the besiegers’ fire, together with the greater number of•jjen, generally obliges the besieged to submit sooner or later.
• h< ‘„ftmatest improvement made in the art of attacking happeneds 1 ‘097, when M. V:\uban first made me of ricochet tiring at theAth, whereby the besieged placed behind the parapetsh *' re as much exposed to the tire of tire besiegers as it there hadcon n 0 parapets ; whereas, before, they had been secure as long asP ara pet was not demolished: and the worst is, that there canao femedv found to prevent this enfilading, without falling0 inconveniences almost as bad as those which we endeavouru av oid,
V °L. 11—NO. 87.
Definitions. 1. In the plan and profile, Plate LXXIII. fig. I,the part NODE V represents a bank ofearth called the parapet,its use is to cover the troops from the lire of the enemy. 2. Thepart D I. is called the talus or piunge, and is a little sloping tow ardthe further side ; it does not rise perpendicularly but slopes oneach side as represented by C D and E F. 3. \\ hen the heightof the parapet exceeds 41 feet w hich is generally the case, a partABC is raised to elevate the men sutliciently to fire over tireparapet; this is called the banquette or foot-bank, it rises to theilat part B C bv a gentle slope AB ; sometimes there are two ban-quettes. 4. 11 I represents the ditch behind the parapet, havingthe slope Gil, towards the parapet, called the scarp, and IK 011the opposite side called the counterscarp. 5. The flat part FG iscalled berme, and serves to lodge the loose earth that may fallfrom the parapet. 6. K I, represents the glacis, which is generally ina line with the talus DE. 7. In Plate LXX1V. fig. 1, the part FEAj LN is called the bastion. S. AE, AL, the faces of the bastion,j 9. EE, LN, the flanks. 10. EG, the curtin. 11. FN, theI gorge of the bastion. 12. AG, BE, the lines of defence. 13 AB,the exterior side of the polygon. 14. CD, the perpendicular.13. Any line which divides a work into two equal parts is calledthe capital of that work. 16. a, b, c, the counterscarp of the ditch.17. A, M, the flanked angles. 18. H, E, L, the angles of theshoulder, or shoulder only. 19. G, E, N, the angles of the flank.20. Any angle whose point turns from the place is called saliantangle, such as A, M : and any angle whose point turns towards theplace, re-entering angle, such as b, F, N. 21. It there be drawntwo lines parallel to the principal or outline, the one at three toisesdistance, and the other at eight from it, then the space yx inclu-ded between the principal one and that farthest distant is called therampart. And the space x, contained by the principal line andthat near to it, and which is generally stained black, is called theparapet. There is a fine line drawn within four feet of the parapet,which expressesthe step called banquette. All works have a para-pet of three toises thick, and a rampart of from 8 to 10, besidestheir slopes. The rampart is elevated more or less above the levelof the place, from 10 to 20 feet, according to the nature of theground, and the particular constructions ot engineers. 22. Thebody of the place is all that which is contained within this firstrampart; for which reason it is often said to construct the body ofthe place: which means, properly, the construction of the bastionsand curtins. 23. All the works which are constructed beyondthe ditch, before the body of the place, are called outworks.
General Principles, or Maxims.
1. The plan of every place that is to be fortified, ought first to-be circumscribed with one of the most convenient polygonal fi-gures, that can be fitted to that place, and this polygon is to be for-tified.
2. The more regular fhe circumscribing polygon is, the better.
3. It is a disadvantage, to be necessitated to extend the worksabout a fortress.
4. Every side of the polygon, as much as is possible, should hiequally fortified, that the enemy' may not have it in his choice toattack a part more weak than the rest..
3. All works ought as much as possible to be easy to build, hardto destroy, and not difficult to be repaired.
6. The works about a fortress should be so contrived, as to coverthe defendants, discover the approaches to the enemy, and adaptedto the common w eapons of defence.
7. Each work should he defended from as many as may be and
liable to be attacked from as few places as possible. •
8. These works, made to defend one another, should be suffi-ciently large to contain the troops and cannon necessary for thatdefence.
9. Works which are to flank one another ought not to, he at agreater distance than the point bank flight of a musket-shot.
10. The works farthest distant from the body of the place
6 G should