PEOGRESS m EXPLOSIVES — GUTTMANN. 285 



There is no need for me to detail the manufacture of powders. 

 Nitrocellulose powders are made from dry nitrocellulose, in a mixing- 

 machine, using a solvent (generally ether alcohol or ether acetone). 

 In man}^ factories the nitrocellulose is made anhydrous by soaking it 

 in alcohol, and then squeezing it out in a press. Some think that the 

 quality of the powder is affected by this method. Some have found a 

 loss of substance up to 5 per cent to take place with certain nitrocot- 

 tons. The mixture is then rolled under a pair of heavy rolls into 

 sheets of the required thickness, cutting them up into squares, and 

 afterwards drying these. In some services ribbons are used instead 

 of grains, and in others threads or tubes are made of such powder 

 and cut into sticks of the length required for the charge. In Ger- 

 many camphor was formerly added to the powder while kneading it. 

 Some countries leave a certain amount of the solvent in the powder, 

 and formerly in France a little amyl alcohol was added, while now 

 diphenylamine has been adopted; this was already used in 1889 in 

 Germany for C/89 powder made by the Cologne-Rottweil factory. 



Ballistite is made in a different way. Soluble nitrocellulose in the 

 shape of a fine powder is suspended in fifteen times its own bulk of 

 water and nitroglycerin added, the mixture being stirred by means 

 of compressed air. This causes the nitroglycerin to dissolve up the 

 nitrocellulose, the water acting as a carrier only. The paste result- 

 ing in this way is then brought under steam-heated rolls, weighted to 

 exert a pressure of 100 atmospheres, to thoroughly incorporate it, and 

 then mixed by rolling the sheets over and over until they are quite 

 satisfactorj^ The sheets so obtained are then cut up into flakes, 

 cubes, strips, etc., as required. 



You will readily understand that every weapon may, and generally 

 does, require a different powder in order to give the desired velocity 

 and not to exceed the permissible limits of pressure. It is obvious 

 that it would be very easy to alter the composition in every case, 

 but as a matter of course such an expedient would be quite unde- 

 sirable alike from a manufacturing and from a service point of 

 view. Hence already in the days of black powder it has been the 

 custom to vary the shape and size of the powder. We thus have rib- 

 bons in France, strings in Great Britain, flakes and tubes in Germany, 

 cords of square section in Italy, short multiperforated cylinders in 

 the United States, cubes from ballistite, spiral sporting powder in 

 Germany, the poudre peigne (spiral powder with comb-shaped in- 

 cisions) of French inventors, etc. Further, these powders may then 

 be made in various lengths, breadths, or thicknesses, and with various 

 kinds of holes, incisions, etc. It is quite impossible to generalize and 

 to say that a particular form is good or bad, because it probably does 

 suit a special weapon. It is a fact that up to a certain size round 



