454 Sir Andreiv Noble [Jan. 18, 



energies of the nitroglycerine and nitrocellulose powders not made 

 their adoption a necessity. 



I have never been able to understand why sulphur was so long 

 retained as a component of gunpowder. In the English Service it 

 was, shortly before the adoption of modern powders, almost dis- 

 pensed with in Cocoa powder when the proportion of sulphur was 

 reduced to 2 per cent. ; but as I was curious on the subject, after the 

 dissolution of the first Committee of Explosives, I had four powders 

 made, called in the tables A, B, C, and D, and you will observe that 

 in two of these powders sulphur was altogether dispensed with (the 

 small quantity of sulphur shown in the table is accidental, derived, 

 doubtless, from the incorporating mills), while in C and D one 

 powder had the sulphur increased by about 40 per cent., and in the 

 other there was a reduction of 40 per cent., and you see from the 

 table that the sulphurless and reduced sulphur powders give the 

 highest energies, while the increased sulphur is near the bottom of 

 the list. 



Another point worthy of attention is, that in the old powders 

 made up with different proportions of the same ingredients, if ever 

 the volume of gas is high you will find the units of heat low. Thus, 

 taking four of the last five powders on the table, you see that in the 

 Mining and C powders the volume of gas is large, 860 and ?A1 c.c. 

 per gramme, while the units of heat are very low — namely, ol7 and 

 525 respectively. With the Spanish and the Cocoa, on the other 

 hand, the volume of gas is very low, 234 c.c. and 198 c.c. per 

 gramme, but with these two powders the units of heat are large — 

 namely, 767 and 837 units respectively — and, in consequence of the 

 higher heat, the erosive power of these two last powders is corre- 

 spondingly high. 



With the view, however, of studying the question of the most 

 effective use of the gunpowders then in the Service, I had, two or 

 three years before experiments commenced with the Nitroglycerine 

 and Nitrocellulose powders, a gun of 32 calibres in length bored to a 

 diameter of 5-87 inches, and I had five successive chambers, the 

 largest chamber being five times the capacity of the first chamber, 

 and in each chamber four densities were employed — namely, approxi- 

 mately, '24, '48, "72, and '96 — while the powders employed were 

 R.L.Gg? Pebble, Prismatic, and two descriptions of Prismatic cocoa 

 powder. 



I should only fatigue you were I to attempt to epitomise the 

 whole of these experiments, but I may mention that at the end of the 

 series with each chamber I fired a series with increasing weights of 

 shot. The successive weights of shot were 30, 60, 90, 120, 150, and 

 360 lb., and I give, for the sake of comparison, the results of this 

 series in the first chamber for the R.L.G.2 and one of the Cocoa 

 powders. 



