FORTIFICATION. 



tions are necessarily more obtuse, the ra- 

 velines are thrown more towards a right 

 angle with each other, and afford mutual 

 support, even in cases of assault. 



The communications with the ravelines 

 are effected by the aid of bridges, when 

 wet ditches are in question, as may be 

 seen in the third face, y z, where the 

 bridge V is carried over from the curtain 

 to the counterscarp, or outer face of the 

 ditch, so as to afford access to the rave- 

 line K, in which is the intrenched redoubt 

 L. The double lines, T, represent a 

 channel of about fourteen feet broad, and 

 about six or seven feet deep, made in 

 all ditches that are at any time filled 

 with water. These channels are called 

 cunettes, or cuvettes; they are usually 

 lined with masonry, and kept full, so as 

 to prevent a surprise : when the water is 

 allowed to fill the whole of the ditch, 

 which should generally be to the depth of 

 nine or ten feet, or at all events so as not 

 to be fordable, the cunette proves a for- 

 midable obstacle. 



The bridges have barriers at their 

 outer ends, and towards their inner ends 

 generally a draw-bridge, besides one that 

 lifts immediately under the gateway, to 

 which it gives additional strength. The 

 very small compass allowed for the exhi- 

 biting of suck figures as are indispensably 

 necessary towards the right understand- 

 ing of the subject, absolutely precludes 

 the possibility of showing the dimensions 

 of the ramparts, &c. and occasions the 

 omission of many particulars in the plate, 

 which must be therefore described. The 

 foregoing impediment prevents us from 

 showing the berm, which is a space, al- 

 ways left, between the cordon that runs 

 along the inner brink, or scarp of the 

 ditch, and the foot of the ramparts. Its 

 use is to prevent the latter, when batter- 

 ed, from falling into the ditch ; and it af- 

 fords likewise a very good line of com- 

 munication all round the works. The 

 breadth of the berm is very uncertain ; it 

 should never be less than six feet, even 

 where the works are scarped from the 

 solid rock, and not subject to let fall 

 much rubbish when battered. In the 

 common mode of building ramparts with 

 a revetement of masonry, the berm should 

 be at least ten or twelve feet ; and where 

 only turf facing is used, or that the soil 

 with which the rampart is filled, between 

 the outer and inner faces of masonry, is 

 of a loose nature, the berm should then 

 be full twenty feet broad. The bulk of 

 the rampart should, however, be consi- 



dered also , whether it be much exposed 

 or not; for on these points much vrill 

 depend as to the probable quantity of 

 battered rubbish to be sustained. There 

 used to be a work, called the fausse- 

 braye, carried all round the principal and 

 the edge of the berm : its intention was 

 to defend the ditch, and its fire was in- 

 deed highly destructive ; but the facility 

 with which it could be enfiladed, for it 

 was necessarily Jow, evinced its inutility 

 in general : the immense number of splin- 

 ters falling from the rampart, immedi- 

 ately above, was another formidable ob- 

 jection. The fausse-braye is, therefore, 

 out of repute ; though in some fortifica- 

 tions, a substantial parapet supplies its 

 place, generally of masonry, more for 

 the purpose of stopping the rubbish of 

 a battered rampart, than for the means of 

 sheltering troops. Perhaps the strong 

 hedge, adopted in many instances, may 

 be preferable ; to say the least, it is 

 far cheaper, and stands to more advan- 

 tage on the berm, than a heavy range of 

 masonry. 



The first draw -bridge generally con- 

 nects with the body of the bridge passing 

 over the ditch, and is drawn up by 

 persons standing on the berm ; while that 

 draw-bridge, which rises close up against 

 the gate, is so contrived as to bury itself, 

 for at least its whole thickness, into the 

 masonry ; whereby its edges are secured 

 from the grazing of shots ranging against 

 the wall, and the possibility of wrench- 

 ing the draw-bridge out of its place is 

 sufficiently obviated. The gates usually 

 close in the ordinary way of all large 

 ones, that is, in two leaves, meeting in 

 the centre ; over them a portcullis is 

 sometimes suspended horizontally ; its 

 hinges being close behind the gates when 

 shut. This immense machine resembles 

 a very large harrow, and lets down, 

 much like the ports of a ship, until it 

 hangs vertically, close at the back of 

 the gates, and being secured with long 

 iron stays, beams of wood passing like 

 window bars into the wall, and other de- 

 vices, it proves adequate to the repulsion 

 of even a common sized petard. Some 

 places have a succession of such gates 

 and portcullices, one behind the other, 

 which, added to the casematesbeing lined 

 with defenders, renders it almost impos- 

 sible to force the passages. When mat- 

 ters are driven to extremity, owing to the 

 raveline being possessed by the enemy, 

 and by the defences on the curtain and 

 flanks being rased, the gateways are 



