164 MILITARY SCIENCES. 



carried on in such mine galleries, as for instance the one between King 

 Henry V. of England and the Sire de Barbazan, commandant of Melun, in 

 the year 1420. 



In our own times the reduction of a fortified place may be effected either 

 by blockade or investment, by surprise, by an unexpected open attack, by 

 bombardment, or, finally, by a regular siege. What is meant by the four 

 first methods is explained by their names ; we have to do, therefore, only 

 with the last. 



1. Attack of Fortified Places. 



If a fortress is to be formally invested, it is first surrounded, to cut off all 

 succor and assistance, with a line of circumvallation, established at about 

 two miles distant, and constructed according to the rules of fortification ; 

 or at least all roads running to the place are taken possession of, and all 

 the adjacent villages and important localities. At the same time, depots 

 for artillery and siege material, magazines, &c., are established. From this 

 line of circumvallation, or from the occupied points, approaches are now 

 made, by means of ditches of communication (boyaux), upon the prolonga- 

 tion of the capitals of the front destined to attack {pi. 49, fig. 1), which 

 ditches run in zigzag, so as not to be enfiladed from the place. When 

 within 1800 feet of the fortress, that is, near the foot of the glacis, a trench 

 is established, the first parallel, which surrounds the whole front to be 

 attacked. The first parallel serves as a place of assemblage for artillery 

 and infantry, and for the location of those batteries from which curved 

 fires are to be given, that is, for the enfilade and ricochet, and for the 

 mortar batteries. These batteries should enfilade, not only the long lines 

 of the front attacked, but also the curtains of the adjacent fronts. Not to 

 interfere with the communications, the batteries are established, not in, but 

 before or behind the parallel. From the first parallel approaches are again 

 continued by boyaux in zigzag still upon the lines of the capitals, until a 

 distance of about 900 feet from the covered-way is attained, when the 

 second parallel is established, which, as well as the first, must be secured 

 from attack at the extremities. In this parallel, which serves properly only 

 as a place for rest and assemblage, batteries are seldom established, at most 

 some elevated counter-batteries, and especially mortar batteries. Still 

 approaching, by means of the boyaux {pi. 49, fig. 3 dd), the third parallel, 

 gg, is established near the salients of the covered-way, and in this are 

 placed the counter-batteries, x. Between the second and third parallels, a 

 half parallel is usually established {figs. 2 and 4), which incloses the bastion 

 of the attacked front, and serves to cover the further advance of the boyaux 

 by a fire of small arms, or to attack with the fire of artillery points which 

 could not be properly reached from the second parallel. When approaches 

 are continued from the third parallel, upon the line of the capitals, against 

 the salients of the covered- way, high masses of earth are thrown up on the 

 right and left of the line of the capitals, the trench cavaliers {Jig. 3 hw), by 

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