456 



Sir Andreiv Noble 



[Jan. 18, 



With this powder the results are very different, the velocities are 

 lower with all weights of shot, and the chamber pressures are all 

 through less than half of those with the It.L.G.2 ; but, although the 

 energies reahsed with the slow-burning powder are considerably less 

 than with the R.L.G.2, the increment of energy is much greater. 



In the former, between the 30-lb. and ;360-lb. shot, there is only an 

 increase of energy of 25 per cent. ; with the Cocoa powder, the energy 

 is more bhan doubled. But I must not lecture on these experiments, 

 and I will only refer you to the table here, in which the results are 

 given with two powders — Pebble and a quick-burning Cocoa powder ; 

 the charge with this second chamber being 20 lb. 



Pebble. 



From these two tables you will see that with the increasing- 

 weight of shot the velocities vary from 2479 and 23S2 f.s. to 903 

 and 901 f.s., the chamber pressure with the heaviest shot being more 

 than double that with the lightest, while the energy of the shot is 

 increased by nearly 60 per cent. 



These experiments, however, led to most important results with 

 respect to the velocities and energies obtainable from the old powders ; 

 and a very great step in advance was made by my firm, who, acting 

 on deductions from these and from other experiments in closed vessels 

 carried out at Elswick, made 8-in. M.L. and B.L. guns, in which at 

 a single bound the velocities at the same chamber pressures were 



