Sept. 1, 1864.] THE TECHNOLOGIST. 



USES OF GUN-COTTON. 55 



The fifth principle, therefore, is, to make it destructive — to cause it 

 to shatter everything to pieces which it touches, and for this purpose 

 you have only to deprive it of room. Give it room and it is obedient ; 

 imprison it, and it rebels. Shut up without room, there is nothing 

 tough enough or strong enough to stand against it. 



To carry this into effect, the densest kind of gun-cotton must be 

 used. It must no longer consist of fine threads or hollow textures 

 wound on roomy cores. All you have to do is to make it dense, solid, 

 hard. Twist it, squeeze it, ram it, compress it ; and insert this hard, 

 dense cotton rope, or cylinder, or cake in a hole in a rock, or the drift of 

 a tunnel, or the bore of a mine ; close it up, and it will shatter it to pieces. 

 In a recent experiment, 6 ounces of this material set to work in a tunnel 

 not only brought down masses which powder had failed to work, but shook 

 the ground under the feet of the engineers in a way never done by the 

 heaviest charges of powder. 



To make gun-cotton formidable and destructive, squeeze it and close 

 it up ; to make it gentle, slow, and manageable, ease it and give it room. 

 To make gunpowder slow and gentle, you do just the contrary ; you 

 cake, condense, and harden it to make it slow, safe for guns, and 

 effective. 



To carry out this principle successfully, you have to carry it even 

 to the extreme. Ask gun-cotton to separate a rock already half- 

 separated, it will refuse to comply with your request. Give it a light 

 burden of earth and open rock to lift, it will fail. If yoti want it to do 

 the work, you must invent a ruse — you must make believe that the 

 work is hard, and it will be done. Invent a difficulty and put it 

 between the cotton and its too easy work, and it will do it. The device 

 is amazingly successful. If the cotton have work to do that is light 

 and easy, you provide it with a strong box, which is hard to burst, 

 a box of iron for example ; close a small charge, that would be 

 harmless, in a little iron box, and then place that box in the hole 

 where formerly the charge exploded harmless, and in the effort it 

 makes to burst that box, the whole of the light work will disappear 

 before it. 



The first trial of English-made gun-cotton was made at Stowmarket 

 in the spring of 1861. A charge of 25 lbs. not only destroyed a tree- 

 stockade, but shattered it into matchwood. 



It is, therefore, the nature of gun-cottcn to rise to the occasion and 

 to exert force exactly in proportion to the obstacles it encounters. For 

 destructive shells this quality is of the highest value. You can make 

 your shell so strong that nothing can resist its entrance, and when 

 arrived at its destination no shell can prevent its gun-cotton charge from 

 shivering it to fragments. 



These are the main principles in the mechanical manipulation of 

 gun-cotton which will probably render it for the future so formidable an 

 instrument of war. Resistances too great for gunpowder only suffice to 



