41 



SIKGK. 





US 



depot* of materials. All the trenches are sunk three feet below the 

 urbee of the ground ; and the earth thrown out forming a mass about 

 Uirw feet high, the troops iu them are effectually covered from the 



view, of the besieged. The general breadth is 10 or TJ f.-et, l.ut 

 greater width is given in places at intervals from each other, where it 

 may be desirable to collect troops and material. 



The first operations of the working-parties take place during the 

 iii.-lit, in order that notne progress may be made before they are 

 discovered by the defenders ; but should the latter suspect that ground 

 is being broken, they frequently discharge light-balls, by the light of 

 which they may discover the places where the men are at work. These 

 places being ascertained, it may be expected that the ground will be 

 cannonaded, or that troops will make a sortie from the fortress, for the 

 purpose of interrupting or driving off the workmen ; and in order that 

 this intention may be frustrated, the parties are accompanied by a 

 guard of infantry, or covering party, which is placed at about 50 yards 

 in front of the tracing-line. These troops obtain cover if possible, or 

 In- clown on the ground, that they may not be exposed to the 

 defenders' fire; and in the event of a sortie being made, they are 

 ready to repel it : squadrons of cavalry are also, if the ground permits 

 it, stationed near the extremity of the parallel, that by a rapid move- 

 ment they may take in flank and cut off the retreat of the sortie. 



The general uses of the paralleli) are to connect the lines of approach 

 by a covered line of communication, to allow the trenches to be kept 

 clear of troops and free for the workmen, and, affording cover and pro- 

 tection to the guard of the trenches and a strong position for them 

 to remain in during the day, to serve as lines of countervallation in 

 confining the garrison of the place. As soon as the first parallel is 

 finished, the guard of the trenches is moved into it, for the purpose of 

 protecting the succeeding operations. While the approaches are being 

 pushed forward, or indeed while the first parallel is being completed, 



the batteries c, c, c , are formed cither iu or in advance of the first 



parallel to keep down the fire of the place cither by direct or enfilade 

 lire as shown by the dotted lines. 



Since the trenches leading from the first parallel towards the place 

 ought not to be enfiladed from thence, it is evident that they must be 

 formed in zig-zag or oblique directions a a a, &c. , crossing and rccrossing 

 the produced capitals of the bastions or ravelins ; and that the several 

 branches, if produced, should fall on the exterior of all the works of 

 the place. The first oblique boyeau (branch) of the trench may be 

 defended by the fire of the parallel ; but the second may, if found 

 necessary, be protected by the fire of troops stationed in a small trench, 

 a b, called a parallel boyeau, at the angle between the first and second 

 branches ; and a abort branch for the like purpose is generally formed 

 at the angles of all the zig-zag trenches. If the directions of the several 

 i'Mi'lue branches are not laid down on the ground, from a plan of the 

 intended operations previously made on paper, the engineer endea- 

 vours, during the daylight, to observe, in the direction of the most 

 advanced part of the glacis towards his tight or left hand, some object 

 towards which the tracing-line maybe stretched and the trench carried 

 on. These trenches are then executed by the working-parties, in the 

 aune manner an the great parallel was formed. At the siege of 

 liadajon, in 1812, a French corporal, in the dusk of an evening, 

 dexterously displaced a tracing-line, which bad been stretched by the 

 1 1 engineers, and directed it so that the trench executed along it 

 might have been enfiladed by three guns on the ramparts of the castle. 

 I f the derangement had not been discovered before darkness came on, 

 the labour of the whole night would have been Inet, and casualties 

 might have occurred from the firo which the garrison might have 

 directed along the trench. The workmen are usually relieved after it 

 is dark, in order that the change may not be observed from the 



fortress ; but the officers should bo relieved earlier, that those who 

 come on duty may have light enough to examine the actual state of 

 the works, and to take measures for directing the operations of the 

 men during the night. 



When the heads of the trenches have arrived within 300 yards of the 

 covered-way, which is usually about the fourth night from the time of 

 opening the trenches, a second parallel, B B B, is formed, in order to 

 facilitate the communication between the several lines of approach, ami 

 to protect the working-parties, for it is evident that having got half 

 way between the first parallel and the place, as the boyeaux advance 

 the working-parties in them are nearer to the enemy than to their 

 supports. This trench may be extended along the particular points 

 attacked, and its extremities may be terminated by redouts, or con- 

 tinued till they fall into the first parallel. It is executed by flying sap 

 [SAP], that the men may bo quickly protected from the fire of musketry 

 in the covered-way, which might now begin to take effect.* One of 

 the principal means of accelerating the surrender of the fortress is that 

 of enfilading the ramparts, in order to dismount the guns and drive the 

 defenders from the parapets. But in order to be effective, the range for 

 ricochet fire should be short ; for this reason fresh batteries, d d d, &c., 

 are raised in the directions of the produced faces of the works, in in- 

 near the second parallel, which thus may form a secure communication 

 between them, and are armed with guns moved up from the first parallel. 

 [BATTEKV ; KICOCHDT.] From the game lotteries also an oblique fire 

 may sometimes be directed against the interior of the flanks and curtains, 

 and a plunging fire into the ditches, in order to impede the commu- 

 nication between the place and the outworks. All the different ricochet 

 batteries commence firing at the same time, that the attention of the 

 defenders may be divided, and that they may be prevented from con- 

 centrating all their fire upon one battery ; the guns also should be fired 

 singly, and at intervals so regulated that there may be always some 

 shot or shells in the air, for thus the enemy will have little time to 

 repair the damage done to his artillery or to the parapets. The firing 

 should be commenced during daylight, in order that the artillerymen 

 may be able to determine by trial the charge of powder and the degree 

 of elevation for each piece, so that the shot may just clear the parapet 

 of the work to be enfiladed ; this being obtained, the direction of the 

 piece may be preserved by means of timbers nailed to the platform, 

 and thus the fire may be kept up with equal accuracy by night and 

 by day. 



After the fire from the ricochet batteries has partly silenced that of 

 the place, the trenches of communication are continued in zig-zag 

 directions as before, and with the like precautions against being 

 enfiladed from the fortress and its covered way. These and all the 

 succeeding trenches may be executed by full sap [SAP], while the fire 

 of the besieged continues in activity ; but if that fire should become 

 at any time relaxed, the opportunity may be seized of carrying on 

 some part of the approaches in a more expeditious manner. When the 

 heads of the oblique trenches are about half-way between the second 

 parallel and the foot of the glacis, a ilemi-]>ara!lel, rt,&c., is carried 

 out on each side of the produced capitals of the works attacked, till it 

 meets the prolongation of the crest of the covered-way : its use is to 

 protect the works which are to bo executed in its front by a fire of 



It must be understood that this refers to smooth-bored fire-arms. 



