the Force of fired Gunpowder. 253 
substance which I have already described, and from which it 
was with some difficulty that it was freed, and rendered fit for 
another experiment. 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 expe- 
riments. I had seen, indeed, from the beginning by their looks, 
that they thought the precautions I took to confine so incon- 
siderable 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 conceived 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 oiled leather under it, was 
pressed down upon the end of the barrel by the same weight 
as was employed for that purpose in the first experiment, 
namely, a cannon weighing 8081 lbs. In order to give a more 
perfect idea of the result of this important experiment, it may 
not be amiss to describe more particularly one of the principal 
parts of the apparatus employed in it, I mean the barrel. This 
barrel (which though similar to it in all respects was not the 
same that has already been described,) was made of the best 
hammered iron, and was of uncommon strength. Its length 
was 2-| inches ; and though its diameter was also 2 J inches, 
the diameter of its bore was no more than ^ of an inch, or less 
than the diameter of a common goose quill. The length of 
its bore was 2.15 inches. Its diameter being 2^ inches, and 
the diameter of its bore only ~ of an inch, the thickness of the 
LI 2 
