376 CHEMICAL DISCOVERY AND INVENTION 



afloat were the 68 pounders with smooth bores. The idea of 

 rifling the gun for the purpose of giving the projectile the spin 

 which increases greatly its accuracy of fire had not at this time 

 been actually adopted in practice. With this very important 

 change two names will always be connected, the late Lord 

 Armstrong (died 1900) and the late Sir Andrew Noble (died 1915), 

 who for some forty years were associated together in the great 

 Elswick Ordnance Works near Newcastle-on-Tyne. To the 

 former we owe the rifled breech-loading gun with wire-wound 

 cylinder, to the latter the invention of the chronoscope, by which 

 minute fractions of time may be measured, beside famous 

 experiments on the pressures attained in large guns. 



Up to about 1886 black gunpowder had been used, but as it 

 had been found that with increased length of the gun the pressure 

 on the breech became injurious to the gun without giving the 

 desired velocity to the projectile, many modifications were tried 

 in the size of the grain, and in the cubes, prisms or perforated 

 slabs in which form the powder was used. The old powder, 

 however, had one inseparable defect, namely, the large quantity 

 of smoke produced in firing. This arises from the fact that 

 black gunpowder is composed of nitre, charcoal, and sulphur 

 in the proportions on the average of 75 : 15 : 10 per cent re- 

 spectively. Hence when burnt the potassium of the nitre is 

 converted into a mixture of potassium carbonate, potassium 

 sulphate, with a small quantity of potassium sulphide, all of 

 which are solids, and being dispersed in fine powder give rise to 

 clouds of smoke. At the time referred to the service powders 

 used by the various European Powers had the composition 

 shown in the following table : 



Country. Nitre. Charcoal. Sulphur. 



England Black Powder . 75 15 10 



Brown 79 18 3 



Sweden . . ' . . 75 15 10 



Russia .... 75 15 10 



Prussia .... 74 16 10 



Saxony .... 74 16 10 



United States ... 76 14 10 



Austria . . . . 75-5 14-5 10 



France .... 75 12-5 12-5 



According to Thorpe's Dictionary of Applied Chemistry 

 Chinese gunpowder contained of nitre 61-5, charcoal 23, and 



