the Force of Fired Gwipowder. 129 



The report of the explosion was extremely feeble, and 

 so little resembling the usual report of the explosion of 

 gunpowder, that the by-standers could not be persuaded 

 that it was anything more than the cracking of the bar- 

 rel, occasioned merely by its being heated by the red- 

 hot ball ; yet, as I had been taught by the result of 

 former experiments not to expect any other report, and 

 as I found upon putting my hand upon the barrel that it 

 began to be sensibly warm, I was soon convinced that 

 the powder must have taken fire ; and after waiting four 

 or five minutes, upon causing the weight which rested 

 upon the hemisphere to be raised, the confined elastic 

 vapour rushed out of the barrel. Upon removing the 

 barrel and examining It, Its bore was found to be 

 choaked up by the solid substance which I have already 

 described, and from which it was with some difiiculty 

 that it was freed, and rendered fit for another ex- 

 periment. 



The extreme feebleness of the report of the explosion, 

 and the small degree of force with which the generated 

 elastic fluid rushed out of the barrel upon removing the 

 weight which had confined It, had inspired my assistants 

 with no very favourable Idea of the Importance of these 

 experiments. I had seen, indeed, from the beginning, 

 by their looks, that they thought the precautions I took 

 to confine so inconsiderable a quantity of gunpowder as 

 the barrel could contain perfectly ridiculous ; but the 

 result of the following experiment taught them more 

 respect for an agent, of whose real force they had con- 

 ceived so very Inadequate an Idea. 



In this second experiment. Instead of 10 grains of 

 powder, the former charge, the barrel was now quite 

 filled with powder, and the steel hemisphere, with Its 



VOL. I. 9 



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v: 



