THE APPLICATIONS OF EXPLOSIVES. 



305 



completely purify it, but it also renders it possible to mold it into 

 convenient forms and to compress it so as to greatly increase its 

 efficiency in use. For this purpose the pulp is suspended in water 



Torpedo Cases and Blocks of Wood destroyed by a Naval Detonator. 



and pumped to a molding press, where, under a hydraulic pressure 

 of one hundred pounds to the square inch, it is molded into cylin- 

 ders or prisms about three inches in diameter and five inches and 

 a half high, and these are compressed to two inches in height by 

 a final press exerting a pressure of about sixty-eight hundred pounds 

 to the square inch. As this is regarded as a somewhat hazardous 

 operation, the press is surrounded by a mantlet woven from stout 

 rope to protect the workmen from flying pieces of metal in case 

 of an accident. The oper- 

 ation is analogous to that 

 employed in powder-mak- 

 ing, where the gunpowder 

 has been pressed in a great 

 variety of forms and into 

 single grains weighing sev- 

 eral pounds apiece. 



Even under the enor- 

 mous pressure of the final 

 press the compressed gun cotton still retains from twelve to six- 

 teen per cent of water, and in this form it is quite safe to store 

 and handle. When dry it is very combustible and burns readily 



Testing Detonators on Iron Plates 



