MILITARY AND NAVAL ORGANISATION. 



each branch of trade are too few to insure a 

 healthy competition. To reconcile these difficulties, 

 government purchases stores by contract from the 

 private manufacturers to a greater or less extent 

 according to circumstances, and makes the re- 

 mainder it may require in its own workshops, as a 

 check upon the prices charged. 



WORKS. 



For defensive purposes, the strength of an army 

 or garrison is materially augmented by the inter- 

 position of physical obstacles to an enemy's advance. 

 If an army be in the field, it is usual to throw up 

 some sort of breastwork to cover its front or 

 flank, and give the men time to run to arms in the 

 event of an unexpected attack. The simplest of 

 all obstacles is a row of abattis, consisting of trees 

 cut down, and laid in a row with their boughs 

 outwards ; the boughs may be pointed, to render 

 them more annoying to an assailant. Next would 

 be chevaux-de-frise, formed by iron or wooden 



stakes set cross-wise in a strong beam, so that it 

 will always stand, and yet be a difficult object to 

 support. 



If time allows more solid works, the simplest is 

 a parapet, formed by digging a ditch and throwing 

 up the earth behind it to form a mound as steep as 

 the nature of the soil will allow. The ground before 

 the ditch should be cut to a gentle slope, called 

 the glacis, that an enemy might be fully exposed 

 in approaching. The work can be yet more 





ABC, parapet ; G, ditch ; F, glacis ; D, fraise ; E, stockade. 



secured by adding stockades and fraises, which 

 are stout beams sunk in the ground, and only 

 surmountable by climbing or battering down by 

 artillery. A section of a simple field-work is 

 shewn in the following diagram. This shews the 

 form of the breast-work ; but it would be little 

 formidable if only commanding those approaching 



A 



Line of Field-works : a, redan ; b, bastion ; c, curtain. 



immediately in front, which is all that it would do 

 if completely straight To obviate this, projec- 

 tions are made, called flanking defences, within 

 range of each other, when a fire may be opened 

 on the enemy attacking the front of the breast- 



work. These projections may be simply redatit, 

 or the more elaborate bastions. 



Permanent works of fortification are those by 

 which towns and fortresses are defended. They 

 are constructed on the principle of field-works, 

 though of a more solid and formidable construc- 

 tion, having greater height, more perpendicularity, 

 and being faced commonly with masonry or iron 

 plates ; outworks are also constructed in front of 

 the main ditch, to constitute more than one line of 

 defence. The circuit of the place to be defended 

 is traced as a polygon, probably of many sides ; 

 each side of the polygon becomes a curtain, and 

 at each angle is erected a bastion. A massive 

 rampart is drawn on these lines, and the parapet 

 is formed upon it, with banquettes behind for the 

 defenders and guns to stand upon. In front of 

 each curtain, a redan, demi-lune, or ravelin is 

 made, of less elevation than the curtain, so as to 

 be commanded by it, and not to obstruct its fire. 

 A smaller ditch is dug in front of the ravelins, and 

 before that, at a still smaller elevation, is the 

 covered-way, which is the outmost defence, and 

 from which the glacis slopes down to the country 

 round. In fortifying a place, a skilful engineer 

 takes advantage of all natural eminences, so that 

 it rarely happens that the polygon is a regular 

 one. To prevent shot from bounding along the 

 works in a ricochet fire, and enfilading perhaps a 

 whole battery, earthen mounds called traverses 

 are erected at intervals. As a science, fortifica- 

 tion was first brought to perfection by Vauban, 

 and his system still continues in vogue with com- 

 paratively trifling modifications. The plan of a 

 portion of Vauban's first system is shewn in the 

 accompanying sketch : 



Siege of a Hexagonal Fortress : 



A, bastions ; B, curtains ; C, tenailles ; D, ravelins ; F, covert- 

 way ; G, glacis ; H, ditch ; a, first parallel ; b, approaches ; c, 

 second parallel ; d, third parallel, right attack ; t, third parallel, 

 left attack ; ft, breeching batteries- 



As the guns of such a work command every 

 point around, it is only possible to approach it by 

 trenches. These are cut zigzag, with great danger 

 to the sappers ; and when a sufficiently near point 

 is reached, the trench is carried in a direction 

 parallel to the walls of the place sand-bags and 

 the excavated earth forming a parapet before it. 

 This line is called a parallel, and batteries are 

 formed along it, with wide places d'armes for the 

 troops to assemble in it. From these batteries the 



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