the Force of fired Gunpowder . 261 
ing again in. these laborious researches, I have thought it right 
not to delay any longer the publication of facts, which appear 
to me to be both new and interesting, as their publication 
may perhaps excite others to engage in their farther inves« 
tigation. 
The principal objects I had in view in the following set of 
experiments were, first, to determine the expansive force of 
the elastic vapour generated in the combustion of gunpowder 
in its various states of condensation, and to ascertain the ratio 
of its elasticity to its density : and secondly, to measure, by 
one decisive experiment, the utmost force of this fluid in its 
most dense state ; that is to say, when the powder completely 
fills the space in which it is fired, and in which the generated 
fluid is confined. As these experiments were very numerous, 
and as it will be more satisfactory to be able to see all their 
results at one cursory view, I have brought them into the form 
of a general table. 
In this table, which does not stand in need of any particular 
explanation, may be seen the results of all these investigations. 
The dimensions of the barrel made use of in the experiments 
mentioned in this table, were as follows. 
Diameter of the bore at its muzzle == 0.25 of an inch. 
Joint capacities of the bore, and of its vent tube, exclusive 
of the space occupied by the leathern stopper, = 0.08974, of a 
cubic inch. 
Quantity of powder contained by the barrel and its vent 
tube when both were quite full, (exclusive of the space occu~ 
pied by the leathern stopper,) 25.641 German apothecary's 
grains, == 24!- grains Troy. 
The capacities of the barrel and of its vent tube were deter- 
M m 2 
