GUN-COTTON 



GUN-COTTON 



rope attached to a sunken weight ; they are con- 

 nected with the shore by electric wires ; a buoy with 

 a signalling apparatus is attached to the mine, and 

 wlieii a ship strikes a buoy it rings a bell in the 

 signalling- room on shore ; if the ship is a friendly 

 one it is allowed to pass, but if it is an enemy's 

 ship the mine is fired by electricity and the ship 

 blown up. (3) Electro-contact mines: these are 

 used only in places where an enemy's ship would 

 pass. When the mine is struck by a passing ship 

 a steel spring or pendulum moves towards the point 

 of impact and thus closes the circuit and fires the 

 mine automatically. 



A powder made by the Explosives Company, and 

 generally known under the name of E. C. Powder, 

 is another form in which gun-cotton can be used. 

 There are two descriptions of this powder viz. 

 sporting and rifle powder ; they are both essentially 

 granulated gun-cotton, and consist of small rounded 

 granules, the sporting powder being coloured orange 

 with aurine, and the ritie powder yellow with picric 

 acid. 



Schultze Powder may be mentioned here as, al- 

 though not strictly speaking a gun-cotton powder, 

 it belongs to the class of explosive compounds not 

 containing nitro-glycerine. The process of manu- 

 facture consists in macerating soft timber from 

 which all resinous and fatty matter has been ex- 

 tracted by chemical means, the residue being pure 

 finely-divided cellulose ; this is saturated with 

 nitric and sulphuric acids, and thoroughly purified 

 by washing. The nitro compound thus formed is 

 finely ground and waterproofed, and then sifted 

 into the various sizes of grain required. Schultze 

 powder has been manufactured since about the 

 year 1860, but E.G. is a powder of more recent 

 date. Both these powders are now largely used 

 for sporting purposes. The great advantages they 

 possess over the ordinary black powder are that 

 an equal velocity is obtained with a very much 

 smaller charge, that they do not foul the gun, and 

 that they are nearly smokeless. But against this 

 must be set the disadvantage that under certain 

 conditions the strain on the breech of the gun is 

 greater. But hitherto the results obtained from 

 these powders when used in military firearms are 

 not sufficiently uniform or regular to justify their 

 adoption for military purposes. There can, how- 

 ever, be but little doubt that a smokeless powder of 

 some sort will, before long, be universally adopted 

 by all the great powers of Europe, not only for 

 rifles, but also for artillery purposes ; it is no longer 

 a question as to whether a smokeless powder should 

 be adopted or not, but which of all the smokeless 

 powders experimented on is the best for adoption. 

 Smokeless powders, in order to be suitable for 

 military purposes, must not be too violent fn their 

 action, they must be able to stand extremes of 

 heat and cold, they must not be very hygroscopic, 

 and they must keep well in store without deteriorat- 

 ing in quality ; and the problem to solve is to find a 

 powder which will fulfil these conditions. Nearly 

 all smokeless powders consist essentially of gun- 

 cotton, or other lower forms of nitro-cotton, acted 

 on by a solvent such as acetic ether or acetone, 

 which reduces the nitro-cellulose to a viscid paste ; 

 the paste is then rolled out into sheets, and the 

 solvent allowed to evaporate ; the sheets are left 

 as a dense horny substance, and are cut first into 

 strips, and then the strips are cut crosswise into 

 grains of any required size ; or the substance can 

 be left in strips or in a fibrous* form. 



The French, in 1887, were the first to adopt a 

 smokeless powder for the cartridges for their new 

 small-bore rifle, the Lebel. It is known as Vieille's 

 powder, or ' Poudre B ; ' its exact composition has 

 been kept a secret, but it is believed that picric acid 

 is mixed with the paste as described above. The 



ballistics attributed to this powder when first 

 introduced were remarkable ; a charge of about 70 

 grains imparted a muzzle velocity of 2000 feet per 

 second, to a bullet weighing 230 grains, fired from 

 a rifle-barrel whose calibre was '315". But it was 

 found that the powder rapidly deteriorated, and that 

 these results were only attainable with recently 

 manufactured powder. Hence in 1889 the French 

 adopted another powder, the French B.N. Powder, 

 the exact composition of which is kept secret. 



The English government, after very exhaustive 

 trials with various kinds of smokeless powders, 

 eventually adopted in 1891 the powder known as 

 cordite for use in Her Majesty's land and naval 

 forces. The name comes from its being made in the 

 form of string or cord, the size of the cord being 

 dependent on the size of the gun for which it is 

 required. It is a nitro-glycerine powder, and con- 

 sists of 58 per cent, of nitro-glycerine, 37 per cent, 

 of gun-cotton, and 5 per cent, of mineral jelly, ace- 

 tone being used as a solvent. These ingredients 

 are thoroughly mixed or incorporated in a machine, 

 in which are two revolving blades somewhat in the 

 form of the screw of a steamer. This process, 

 which takes seven hours, converts the mixture into 

 the form of a thick paste, the paste being the same 

 for all sizes of cordite. For rifle cordite, the paste 

 is pressed through a small hole, '0375" in diameter, 

 in a cylinder, and is wound oft' on to reels, each 

 reel holding 1 Ib. of cordite. The cordite is then 

 dried in a drying-room at a temperature of about 

 105 Fahrenheit to drive off the acetone, and in 

 this form is ready for use for loading into rifle 

 cartridge cases, tor larger guns, the cordite paste 

 is pressed through plates having holes of various 

 diameters the larger the gun the larger the dia- 

 meter of the cord. The sizes at present in use for 

 quick-firing guns are as follows : 



For 3 and 6 pr. guns, diameter -05", length of cord 11 inches, 

 ii 12 ii ii -1", M ii 11 ii 



ii 4-7 ii ii -2", M it 14 ii 



ii 6 i, i. -3", ii M 14 " 



For heavier natures, the diameter varies from '4* 

 to "5", and length of cord is also greater. The 

 weight of a charge of cordite varies from one-halt 

 to two-thirds of that of black powder, and with 

 this charge a higher velocity is obtained with a 

 lower pressure. 



The German military powder is also a nitro- 

 glycerine compound. It is very similar to Nobel's 

 ballistite, in which the proportion of nitro-glycerine 

 and gun-cotton are about equal, benzol being used as 

 a solvent ; and instead of being pressed into cords, 

 it is rolled under rollers into sheets, and then 

 broken up into grains of various sizes. 



The Smokeless Powder Company have also made 

 a powder suitable for military rifles, called rifleite ; 

 as also a very good sporting smokeless powder known 

 as S.S. These powders are made of nitro-cellulpse 

 in the form of nitro-lignine, the various shooting 

 qualities being obtained by the mixture of the 

 higher and lower nitrates of lignine, riitro-benzol 

 being used as a solvent. 



The following powders are extensively used for 

 sporting purposes viz. : Ballistite, already men- 

 tioned ; Cannonite, which is a nitro-cellulose powder, 

 the gun-cotton being dissolved in ether, and formed 

 into a plastic mass, in which form it is pressed 

 through a cylinder with very small holes in the 

 bottom plate, somewhat in the form of rifle-cordite. 

 These thin strings when dried are then broken into 

 grains by being passed through revolving rollers. 

 Amberite is another nitro-cellulose powder, the 

 gun-cotton being mixed with paraffin and shellac. 

 Walsrode is a German powder, and is a pure 

 gelatinised nitre-cellulose. The gun-cotton being 

 completely dissolved in solvents, the plastic mass 

 being divided into grains by rotation in a barrel. 



