It is claimed for this powder that it is quick of ignition, the quickness being probably due to the peculiar structure of the grains which, when looked at under the microscope, have the appearance of coke. The charge for a 12 bore is 33 grains and 1-1/16 oz. shot, which gives a velocity of 1,050 feet per second, and a pressure of 3 tons per square inch. ~Greiner's Powder~ consists of nitro-cellulose, nitro-benzol, graphite, and lampblack. ~B.N. Powder.~--This powder is of a light grey or drab colour, perfectly opaque, and rough to the touch. It consists of a mixture, nitro-cellulose and the nitrates of barium and potassium. Its composition is as follows:-- Insoluble nitro-cellulose 29.13 parts Soluble nitro-cellulose 41.31 " Barium nitrate 19.00 " Potassium nitrate 7.97 " Sodium carbonate 2.03 " Volatile matter 1.43 " This powder is a modification of the Poudre B., or Vieille's powder invented for use in the Lebel rifle, and which consisted of a mixture of the nitro-celluloses with paraffin. ~Von Foster's Powder~ contains nothing but pure gelatinised nitro- cellulose, together with a small quantity of carbonate of lime. The German ~Troisdorf Powder~ is a mixture of gelatinised nitro-cellulose, with or without nitrates. ~Maximite~ is the invention of Mr Hudson Maxim, and is a nitro-compound, the base being gun-cotton. The exact composition and method of manufacture are, however, kept secret. It is made by the Columbia Powder Manufacturing Company, of New York, and in two forms--one for use as a smokeless rifle powder, and the other for blasting purposes. ~Wetteren Powder.~--This powder was manufactured at the Royal Gunpowder Factory at Wetteren, and used in the Belgian service. Originally it was a mixture of nitro-glycerine and nitro-cellulose, with amyl acetate as solvent. Its composition has, however, been altered from time to time. One variety consists chiefly of nitro-cellulose, with amyl acetate as solvent. It is of a dark brown colour, and of the consistency of indiarubber. It is rolled into sheets and finally granulated. ~Henrite~ is a nitro-cellulose powder. ~Normal Powder.~--The Swedish powder known as "Normal" Smokeless Powder, and manufactured by the Swedish Powder Manufacturing Company, of Landskrona, Sweden, and used for some years past in the Swiss Army, is made in four forms. For field guns of 8.4 calibre, it is used in the form of cylindrical grains of a yellow colour, of a diameter of .8 to .9 mm. and density of .790--about 840 grains of it go to one gun. For rifles, it is used in the form of grey squares, density .750, and 1 grm. equals about 1,014 grains. One hundred rounds of this powder, fired in eighteen minutes, raised the temperature of the gun barrel 284 deg. F. A nitro- glycerine powder, fired under the same conditions, gave a temperature of 464 deg. F.