GUN COTTON. 



419 



cal arrangements of which it is made a part. 

 It was Gen. Leuk who discovered that struc- 

 ture was quality, and mechanical arrangement 

 the measure of power, in gun cotton ; and in 

 his hands, a given quantity of the same cotton 

 hecomes a mild, harmless, ineffectual firework, 

 a terrible, irresistible, explosive agent, or a 

 pliable, powerful, obedient workman. 



The first form which Gen. Lenk bestowed on 

 gun cotton was that of a continuous yarn or 

 spun thread. Gunpowder is carefully made 

 into round grains of a specific size. Gun cot- 

 ton is simply a long thread of cotton fibre, 

 systematically spun into a yarn of given weight 

 ;-^r yard, of given tension, of given specific 

 weight. A hank of a given length is reeled, 

 just like a hank of cotton yarn to be made into 

 cloth, and in this state gun cotton yarn is 

 bought and sold like any other article of com- 

 merce. 



This cotton yarn converted into gun cotton 

 may be called, therefore, the raw material of 

 commerce. In this form it is not at all ex- 

 plosive in the common sense of the word. 

 You may set fire to a hank of it, and it will 

 burn rapidly with a large flame ; but if you 

 yourself keep out of reach of the flame, and 

 keep other combustibles beyond reach, no harm 

 will happen, and no explosion or concussion 

 will result. If you lay a long thread of it 

 round your garden walk at night, disposing it 

 in a waving line with large balls of gun-cotton 

 thread at intervals, and light one end of the 

 thread, it will form a beautiful fire-work, the 

 slow lambent flame creeping along with a will- 

 o'-th'-wisp-looking light, only with a measured 

 speed of 6 inches per second, or 30 feet a minute; 

 the wind hastening or retarding it as it blows 

 with or against the line of the thread. This is 

 the best way to commence an acquaintance 

 with this interesting agent. 



Care must be taken not to become too familiar 

 with gun cotton even in this harmless and play- 

 ful guise ; cotton dresses will readily catch fire 

 from it, and it should not be treated -with less 

 care to keep fire from it than gunpowder. In 

 one respect it is less liable to cause danger 

 than gunpowder. Grains of powder are easily 

 dropped through a crevice, and may be sprink- 

 led about in a scarcely noticeable form, but a 

 hank of gun cotton is a unit, which hangs to- 

 gether and cannot strew itself about by acci- 

 dent. 



The second form of gun cotton is an arrange- 

 ment compounded out of the elementary yaru. 

 It resembles the plaited cover of a riding-whip ; 

 it is plaited round a core or centre, which is 

 hollow. In this form it is match-line, and, 

 although formed merely of the yarn plaited 

 into a round hollow cord, this mechanical 

 arrangement has at once conferred on it the 

 quality of speed. Instead of travelling as be- 

 fore only 6 inches in a second, it now travels 

 six feet a second. 



The third step in mechanical arrangement is 

 to enclose this cord in a close outer skin or 



coating, made generally of india-ruiber cloth, 

 and in this shape it forms a kind of match-line, 

 that will carry fire at a speed of from 20 to 30 

 feet per second. 



It is not easy to gather from these changes 

 what is the cause which so completely changes 

 the nature of the raw cotton by mechanical 

 arrangement alone. "VThy a straight cotton 

 thread should burn with a slow creeping mo- 

 tion when laid out straight, and with a rapid 

 one when wound round in a cord, and again 

 much faster when closed in from the air, is far 

 from obvious at first sight ; but the facts being 

 so, deserve mature consideration. 



The cartridge of a common rifle in gun cot- 

 ton is nothing more than a piece of match-line 

 in the second form enclosed in a stout paper- 

 tube, to prevent it being rammed down like 

 powder. The ramming down, which is essec 

 tial to the effective action of gunpowder, is 

 fatal to that of gun cotton. To get useful 

 work out of a gun-cotton rifle, the shot must 

 on no account be rammed down, but simply 

 transferred to its place. xVir left in a gun- 

 powder barrel is often supposed to burst the 

 gua; in a gun-cotton barrel, it only mitigates 

 the effect of the charge. The object of en- 

 closing the gun-cotton charge in a hard strong 

 pasteboard cartridge is to keep the cotton from 

 compression and give it room to do its work. 



It is a fourth discovery of Gen. Lenk, that to 

 enable gun cotton to perform its work in 

 artillery practice, the one thing to be done is 

 to " give it room." Don't press it together 

 don't cram it into small bulk : give it at least 

 as much room as gunpowder in the gun, even 

 though there be only one-third or one-fourth 

 of the quantity (measured by weight). 1 Ib. 

 of gun cotton will carry a shot as far as 3 or 4 

 Ibs. of gunpowder; but that pound should 

 have at least a space of 160 cubic inches in 

 which to work. 



This law rules the practical application of 

 gun cotton to artillery. A cartridge must not 

 be compact, it must be spread out or expanded 

 to the full room it requires. For this purpose, 

 a hollow space is preserved in the centre of the 

 cartridge by some means or other. The best 

 means is to use a hollow thin wooden tube to 

 form a core ; this tube should be as long as to 

 leave a sufficient space behind the shot for the 

 gun cotton. On this long core the simple 

 cotton yarn is wound round like thread on a 

 bobbin, and sufficiently thick to till the cham- 

 ber of the gun ; indeed, a lady's bobbin of cot- 

 ton tihread is the innocent type of the most 

 destructive power of modern times only the 

 wood in the bobbin must be small in quantity 

 in proportion to the gun cotton in the charge. 

 There is no other precaution requisite except 

 to enclose the whole in the usual flannel bag. 



The artillerist who uses gun cotton has there- 

 fore a tolerably simple task to perform if he 

 merely wants gun cotton to do the duty o*" 

 gunpowder. He has only to occupy the samo 

 space as the gunpowder with one-fourth of the 



