Count Rumford’s Experiments, &c. 223 
nature of the explosion which takes place in the inflammation 
of gunpowder; and the nature and properties of the elastic 
fluids generated in its combustion. But the great desideratum, 
the real measure of the initial expansive force of inflamed gun- 
powder, so far from being known, has hitherto been rather 
guessed at than determined ; and no argument can be more 
convincing to show our total ignorance upon that subject, than 
the difference in the opinions of the greatest mathematicians 
Of the age, who have undertaken its investigation. 
The ingenious Mr. RoBitfs, who made a great number of 
very curious experiments upon gunpowder, and who, I believe, 
has done more towards perfecting the art of gunnery than any 
other individual, concluded, as the result of all his inquiries 
and computations, that the force of the elastic fluid generated 
in the combustion of gunpowder is 1000 times greater than 
the mean pressure of the atmosphere. But the celebrated ma- 
thematician Daniel Bernouilli determines its force to be not 
less thaft 10,000 times that pressure, or ten times greater than 
Mr. Robins made it. 
Struck with this great difference in the results of the com- 
putations of these two able mathematicians, as well as with the 
subject itself, which appeared to me to be both curious and 
important, I many years ago set about making experiments 
upon gunpowder, with a view principally of determining the 
point in question, namely, its initial expansive force when fired; 
and I have ever since, occasionally, from time to time, as I 
have found leisure and convenient opportunities, continued 
these inquiries. 
In a paper printed in the year 1781, in the LXXI. Volume 
of the' Philosophical Transactions, I gave an account of an 
