MILITARY PYROTECHNY. 137 



breastwork, E the banquette, B the exterior slope, C the ditch, D the glacis, 

 and H' a bridge over the ditch. Tlie internal space of the magazine is 

 divided into the magazine proper, G, and the ante-room, H. In the walls of 

 the magazine are air-holes, and a,h, and c, show the dilFerent forms of these, 

 a and h being so arranged that no fire can penetrate through them. I are 

 wooden frames, on to which the powder-barrels are rolled over woollen 

 covers, and where they are laid upon covers of the same. In peace, a roof- 

 frame, L, rests upon the magazine ; in war, this is filled with earth. 



h. Musket and Cannon Cartridges. For service-firing, powder is made 

 up into cartridges, either musket or cannon. These cartridges contain 

 usually, along with the powder, the ball also ; for chambered guns alone is 

 the charge separate, and these are often loaded with the ladle or the measure. 



Musket cartridges consist of a piece of paper {pi. 40, Jig. 20), one side 

 of which, that it may wind more closely, is cut obliquely ; this leaf, a, is 

 rolled about a former, b (fig. 21), the ball d set in, and the throat c choked 

 with a tie of linen thread, and struck down upon the ball. Then the car- 

 tridge is filled and pinched together at the top (fig. 22). For cannon car- 

 tridges, bags are made of flannel or parchment ; at present, flannel is used 

 almost entirely. For marking out the form upon the piece of stuffy the 

 pattern board a a' (fig. 23) is used, and a second, which reaches only to the 

 line b b', for the seam : there are also half-pattern boards, when the stufl" is 

 laid double. Each calibre has its own pattern board. The length of the 

 cartridge depends upon its being designed to hold the ball or not. When 

 the bag is sewed with the back-stitch, turned, and felled, the sabot a (fig, 

 24), which has a groove, b, is set in, the ball c is placed in the sabot, and 

 then the head g tied, after which the tie h is made in the groove g witli a 

 firework knot; e is the charge of powder. Often the ball, c (fig. 25), is 

 fastened to the sabot, a, by two strips of tin, crossing each other at right 

 angles ; then the bag is made shorter, and fastened, at h, with a firework 

 knot to the sabot groove. The first cartridges are best. Grape shot can 

 be shaken in over a sabot in a longer bag, the bag tied to a head above and 

 the ball space netted with twine ; they are usually, however, put into tin 

 boxes (fig. 27, section, ^^. 28, view). Over the charge, a, comes a sabot, b, 

 with the groove c, and on this sabot the case d (black for large balls, red for 

 small) is nailed, which has first the iron culot e, then the ball /, and finally 

 a bottom, g, over which the tin case is bent; at c the case is united to the 

 bag by a firework knot. 



c. Fire and Light Balls. Fire-balls are used to set buildings, &c., on 

 fire, and light-balls to discover the movements and w^orkmen of the enemy 

 at night. Both are made in the same manner, only the filling is different. 

 There belong to them an iron skeleton, the carcass (fig. 29), which is 

 covered with a canvas bag, filled warm and formed, a fuse driven into the 

 upper orifice, the sack tied fast to the same, and the slack turned back into 

 the carcass (fig. 30). The fire-ball composition consists of thirty parts 

 coarse powder, ten pitch, ten rosin, five colophon, two tallow, and one part 

 tow. The light ball composition is of one part meal powder, ten parts salt- 

 petre, four and a half sulphur, and one part antimony. 



613 



