Sept. 1, 1864.] THE TECHNOLOGIST. 



THE TECHNOLOGIST. 



ON THE MECHANICAL NATURE AND USES OF 

 GUN-COTTON. 



BY JOHN SCOTT RUSSELL, C.E., F.R.S. 



Gun-cotton is a new power coming under the same category as steam 

 and gunpowder. It is highly dangerous to those who do not possess the 

 necessary knowledge and skill ; hut, like them, it enormously extends 

 human power, and like them, the skill to use it can he rightly and 

 certainly acquired. 



I. Is gun-cotton stronger than gunpowder ? The answer to this is, 

 Yes, sixfold stronger. 



By this we mean that a given weight of gun-cotton, say four ounces, 

 if we hore 1J inch in diameter and 3 feet deep, into hard rock or slate, 

 in a quarry, and put four ounces of gun-cotton into it, it will occupy 

 ahout 1 foot of its length, and the aperture heing closed in the usual 

 manner, and a match-line led from the charge to the proper distance from 

 which to fire it ; and if we next take 24 ounces of best gunpowder, bore a 

 similar hole, and charge it similarly with gunpowder, and close it in 

 the same way ; it has been found that, on these being exploded, the 

 4 ounces of gun-cotton have produced greater effect in separating the 

 rock into pieces than the 24 ounces of gunpowder. The answer is, 

 therefore, that in disruptive explosion the strength of gun-cotton is six- 

 fold that of good gunpowder. 



But the disrupting or bursting power of gunpowder is not always 

 the quality for which we value it most, nor the service we require of it. 

 In mining rocks, in exploding shells, in blowing up fortresses, this 

 property is what we value, and this work is what we require. But we 

 do not want to burst our fowling-pieces, our rifles, our cannon. On 

 the contrary, we want to use a force that shall project the projectile out 

 of the gun without bursting the gun, without straining the gun beyond 

 moderate given limit, which it shall be able to endure. We want, 



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