DISCHARGING OF ORDNANCE. 47$ 



It terminates at the top (A), in a cup (fig. 3. d) ; 

 at the bottom of which, the bore of the tube is di- 

 vided into three very small holes, (see fig. 4.), to 

 prevent the powder falling into the tube. Into this 

 cup, about one grain of the new composition, after- 

 wards alluded to, is put, when the apparatus is to 

 be used. At the top of the apparatus, is a bar of 

 brass (C D), which, at the one end (D), turns up- 

 on a joint ; and, at the other (C), is supplied with a 

 cap, in the centre of which is a steel projection, or 

 hammer, (fig. % e). The cap covers the whole of 

 the raised part (A), at the top of the tube (A B) ; 

 and the hammer nearly fits the cup (fig. 3. d), and 

 is made to strike flat upon the bottom of it (fig. 4. 

 d). Between the joint of the bar (D), and the top 

 of the tube (A), is placed a piece of cork (I), or any 

 elastic substance, to prevent the steel hammer (e) 

 coming too close upon the composition^ before firing, 

 and to make it spring up again after the discharge. 

 The apparatus is united at the top by a frame of 

 brass (G H), which, to prevent its being injured by 

 the firing, is screwed upon another frame of wood 

 (E F). The tube screws into four pieces ; and it 

 was into the hollows left at the joinings of these 

 (a b and c), by only half screwing them, that the dif- 

 ferent substances were put, which are noticed in thq 

 experiments. 



