The various smokeless powders may be roughly divided into military and sporting powders. But this classification is very rough; because although some of the better known purely military powders are not suited for use in sporting guns, nearly all the manufacturers of sporting powders also manufacture a special variety of their particular explosive, fitted for use in modern rifles or machine guns, and occasionally, it is claimed, for big guns also. Of the purely military powders, the best known are cordite, ballistite, and the French B.N. powder, the German smokeless (which contains nitro- glycerine and nitro-cotton); and among the general powders, two varieties of which are manufactured either for rifles or sporting guns, Schultze's, the E.C. Powders, Walsrode powder, cannonite, Cooppal powder, amberite, &c., &c. ~Cordite~, the smokeless powder adopted by the British Government, is the patent of the late Sir F.A. Abel and Sir James Dewar, and is somewhat similar to blasting gelatine. It is chiefly manufactured at the Royal Gunpowder Factory at Waltham Abbey, but also at two or three private factories, including those of the National Explosives Company Limited, the New Explosives Company Limited, the Cotton-Powder Company Limited, Messrs Kynock's, &c. As first manufactured it consisted of gun-cotton 37 per cent., nitro-glycerine 58 per cent., and vaseline 5 per cent., but the modified cordite now made consists of 65 per cent. gun-cotton, 30 per cent. of nitro-glycerine, and 5 per cent. of vaseline. The gun-cotton used is composed chiefly of the hexa-nitrate,[A] which is not soluble in nitro- glycerine. It is therefore necessary to use some solvent such as acetone, in order to form the jelly with nitro-glycerine. The process of manufacture of cordite is very similar, as far as the chemical part of the process is concerned, to that of blasting gelatine, with the exception that some solvent for the gun-cotton, other than nitro-glycerine has to be used. Both the nitro-glycerine and the gun-cotton employed must be as dry as possible, and the latter should not contain more than .6 per cent. of mineral matter and not more than 10 per cent. of soluble nitro-cellulose, and a nitrogen content of not less than 12.5 per cent. The dry gun-cotton (about 1 per cent. of moisture) is placed in an incorporating tank, which consists of a brass-lined box, some of the acetone is added, and the machine (Fig. 29), is started; after some time the rest of the acetone is added (20 per cent. in all) and the paste kneaded for three and a half hours. At the end of this time the Vaseline is added, and the kneading continued for a further three and a half hours. The kneading machine (Fig. 29) consists of a trough, composed of two halves of a cylinder, in each of which is a shaft which carries a revolving blade. These blades revolve in opposite directions, and one makes about half the number of revolutions of the other.