228 



SIR ANDEEW NOBLE: RESEARCHES ON EXPLOSIVES. 



I venture to allude to two other points of interest. I have always thought it 

 probable that the dissociation, for example, of carbonic dioxide into carbonic monoxide 

 and oxygen might be very greatly modified or extinguished by the extremely high 

 pressure at which my experiments have been made ; and I thought it possible that, 

 if dissociation did take place, some indication of the re-formation of carbonic dioxide 

 would appear in the cooling curves, which have been obtained under a variety of 

 conditions and pressures. These curves, however, are singularly free from any 

 indication of disturbance, so that, if any recombination does take place, it has no 

 effect on the extremely regular coolings to which I have alluded, and would seem to 

 prove that the re-formation of CO 2 and H 2 O must take place gradually and in no case 

 per saltum. I have found also, and this point is of some interest, that gases I have 

 taken from the chamber of a 9 '2-inch gun immediately after firing have, when 

 corrected for the air with which they are mixed, the same composition as those which 

 have been fired under similar densities in a close vessel. 



The experiments I have made on erosion with the three explosives referred to in 

 this paper, and on some others, have satisfied me that the amount of absolute erosion 

 is governed practically entirely by the heat developed by the explosion. I had 

 thought that increase of pressure would considerably increase the amount of erosion, 

 but in experiments carried on with cordite and nitrocellulose under pressures varying 

 from 5 tons to 32 tons per sq. inch the erosion was practically entirely independent 

 of the pressure both for the cordite and the nitrocellulose. The results of these 

 experiments are given in Plate 13. 



APPENDIX. 



Abstract of Experiments Referred to in Paper. 



CORDITE MARK I. 



Experiment 1380. Fired in explosion vessel Q, 16 '75 grammes of Mark I cordite. Density of 

 charge - 05. 



Pressure 2-9 tons per sq. inch (442 -1 atmospheres). 



Permanent gases 11,186-7 cub. centims. at C. and 760 millims. 



Aqueous vapour 3296 6 cub. centims. 



RECONCILIATION. 



* The N and contained in air in cylinder not taken into account. 



