THE APPLICATIONS OF EXPLOSIVES. 



309 



down the train of gunpowder to the fuhninate, which then deto- 

 nates and causes the detonation of the dynamite. 



Although gun cotton, nitroglycerin, and their congeners can 

 be and usually are fired by detonation, there has within recent 

 years been a great number of compositions invented which, while 

 formed from gun cotton alone or mixtures of it with nitroglycerin, 

 burn progressively when ignited and are therefore available for 

 use as propellants; and since the products of their burning are 

 almost wholly gaseous, they produce but little or no smoke and 

 are therefore called smokeless powders. As upward of fifty-seven 

 per cent of the products of the burning of ordinary gunpowder 

 are solids or easily compressed vapors, this comparative smokeless- 

 ness of the modern powders is a very important characteristic, and 



TuKl'KDu I'KAl IICI., 



when used in battle they seriously modify our former accepted 

 methods of handling troops. While this is the feature of these 

 powders which has attracted popular attention, a far more impor- 

 tant quality which they possess is the power to impart to a pro- 

 jectile a much higher velocity than black powder does, without 

 exerting an undue pressure on the gun. A velocity of over twenty- 

 four hundred feet per second has been imparted to a one-hundred- 

 pound projectile with the powder that I have invented for our 

 navy, while the pressure on the gun was less than fifteen tons to 

 the square inch. 



Prior to my work in this field all the so-called smokeless pow- 

 ders were mixtures of several ingredients, resembling gunpowder 

 in this respect. But, consideriixg the precise and difficult w^ork 

 that was expected of these high-powered powders and the difficulty 



