128 Experiments to determine 



question, but would most probably render the experi- 

 ment peculiarly beautiful and interesting on other ac- 

 counts ; and I have no doubt but a barrel of glass 

 might be made sufficiently strong to withstand the force 

 of the explosion. Whether it would be able to with- 

 stand the sudden effects of the heat, I own I am more 

 doubtful; but as the subject is so very interesting, I 

 think it would be worth while to try the experiment. 

 Perhaps the apparatus might be so contrived as to set 

 fire to the powder by the solar rays, by means of a com- 

 mon burning glass ; but even if that method should fail, 

 there are others equally unexceptionable, which might 

 certainly be employed with success ; and it is hardly 

 possible to imagine anything more curious than an ex- 

 periment of this kind would be if it were successful. 



But to proceed to the experiments by which I endeav- 

 oured to ascertain the force of fired gunpowder. AH 

 the parts of the apparatus being ready, it was in the 

 autumn of the year 1792 that the first experiment was 

 made. 



The barrel being charged with 10 grains of powder 

 (its contents when quite full amounting to about 28 

 grains), and the end of the barrel being covered by a cir- 

 cular piece of oiled leather, and the flat side of the 

 hemisphere being laid down upon this leather, and a 

 heavy cannon, a twenty-four pounder, weighing 8081 

 lbs. avoirdupois, being placed upon its cascabel in a 

 vertical position, upon this hemisphere, in order to con- 

 fine by its weight the generated elastic fluid, the heated 

 iron ball was applied to the end of the vent tube ; and I 

 had waited but a very few moments in anxious expecta- 

 tion of the event, when I had the satisfaction of observ- 

 ing that the experiment had succeeded. 



