260 Mr. Thompson’s Experiments 
long to heat the powder to that degree which is neceffary in 
order to its being rendered inflammable. 
Now as gun -powder, 'as well as all other bodies, acquires 
heat by degrees, and as fame (pace of time is taken up in this 
as well as in all other operations, it follows, that powder, which 
has been warmed by being put into a piece made hot by repeated 
■firm's:, is much nearer that ftate in which it will burn, or, 1 
may fay, is more inflammable.than powder which is cold ; con- 
fequently, more of it will take fire in a given fhort fpace of 
time, and its action upon the bullet and upon the gun will of 
courfe be greater. 
The heat of the piece will alfo ferve to dry the air in the 
bore, and to clear the infide of the gun of the moifture that 
collects there when it has not been fired for fome time, and 
thefe circumftances doubtlefs contribute fomething to the quick- 
nefs of the inflammation of the powder, and confequently to 
its force. 
As it takes a longer time to heat a large body than a fmall 
one, it follows, that meal-powder is more inflammable than 
that which is grained ; and the fmaller the particles are, the 
quicker they will take fire. The failors bruife the priming 
after they have put it to their guns, as they find it very diffi- 
cult, without this precaution, to fire them off with a match : 
and if thofe who are fond of fporting would make ufe of a 
iimilar artifice, and prime their pieces with meal-powder, they 
would mifs fire lefs often, the fprings of the lock might be 
made more tender, and its fize confiderably reduced without 
any rifque, and the violence of the blow of the flint and flee! 
in ffriking fire being lefiened, the piece might be fired with 
greater precifion. 
o Concluding 
