The various forms of powder invented and manufactured by Mr C.F.  Hengst are chiefly composed of nitrated straw that has been finely pulped.  The straw is treated first with acids and afterwards with alkalies, and the result is a firm fibrous substance which is granulated.  It is claimed that this powder is entirely smokeless and flameless, that it does not foul the gun nor heat the barrel, and is at the same time 150 per cent. stronger than black powder.

The German “Troisdorf” powder consists of nitro-cellulose that has been gelatinised together with a nitrate.  Kolf’s powder is also gelatinised with nitro-cellulose.  The powders invented by Mr E.J.  Ryves contain nitro-glycerine, nitro-cotton, castor-oil, paper-pulp, and carbonate of magnesia.  Maxim powder contains both soluble and insoluble nitro-cellulose, nitro-glycerine, and carbonate of soda.  The smokeless powder made by the “Dynamite Actiengesellschaft Nobel” consists of nitro-starch 70 to 99 parts, and of di- or tri-nitro-benzene 1 to 30 parts.

An American wood powder, known as Bracket’s Sporting Powder, consists of soluble and insoluble nitro-lignine, mixed with charred lignine, humus, and nitrate of soda.  Mr F.H.  Snyder, of New York, is the inventor of a shell powder known as the “Snyder Explosive,” consisting of 94 per cent. nitro-glycerine, 6 per cent. of soluble nitro-cotton, and camphor, which is said to be safe in use.  Experiments were made with it in a 6-inch rifled gun, fired at a target 220 yards away, composed of twelve 1-inch steel plates welded together, and backed with 12-inch and 14-inch oak beams, and weighing 20 tons.  The shots entirely destroyed it.  The charge of explosive used was 10 lbs. in each shell.

Comparative Tests of Black and Nitro Powders, from “American Field."—­ The results given in table below were obtained at the German Shooting Association’s grounds at Coepenick, Berlin.  Penetration was calculated by placing frames, each holding five cards of 1 millimetre in thickness (equals .03937 inch), and 3 inches apart, in a bee-line, at distances of 20 inches.  Velocity, pattern, and penetration were taken at 40 yards from the muzzle of a 12-gauge choke-bore double-barrel gun.  Gas pressure was taken by a special apparatus.  All shells were loaded with 1-1/8 oz. of No. 3 shot, equal to 120 pellets, and the number given below represents the average number in the 30-inch pattern.  The number of sheets passed through gives the average penetration.  One atmosphere equals pressure equal to 1 kilogramme (2.2 lbs.) on the square centimetre, hence 1,000 atmospheres equal 2,200 lbs. on the square centimetre.  The E.C., Schultze, and Walsrode powders were loaded in Elcy’s special shells, 2-1/2 inches long.  The averages were taken from a large number of shots, and the same series of shots fired under precisely the same conditions.