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.

This powder is said to keep well—­a sample kept 3-1/2 years gave as good results as when first made—­is easy to make, very stable, ignites easily, not very sensitive to shock or friction, is very light, &c.  Eight hundred rounds fired from a heavy gun produced no injury to the interior of the weapon.  Samples kept for eleven months in the moist atmosphere of a cellar, when fired gave a muzzle velocity of 1,450 ft. secs. and pressure of 1,312 atmospheres, and the moisture was found to have risen from 1.2 to 1.6 per cent.  After twenty-three months in the damp it contained 2 per cent. moisture, gave a muzzle velocity of 1,478 ft. sees., and pressure of 1,356 atmospheres.  In a 7.5 millimetre rifle, 13.8 grm. bullet, and charge of 2 grms., it gives a muzzle velocity of 2,035 ft. secs. and a pressure of 2,200 atmospheres.  In the 8.4 cm. field-gun, with charge of 600 grms., and projectile of 6.7 kilogrammes, muzzle velocity was equal to 1,640 ft. secs. and pressure 1,750.  A sample of the powder for use in the .303 M. rifle, lately analysed by the author, gave the following result:—­

Gun-cotton 96.21 per cent. 
Soluble cotton 1.80 "
Non-nitrated cotton trace. 
Resin and other matters 1.99 "
                        _______

100.00