PHILOSOPHICAL 
TRANSACTIONS. 
XV. New Experiments upon Gun-powder , with occajional 03 - 
fervations and' practical Inferences ; to which are added , an 
Account of a new Method of determining the Velocities of all 
Kinds of Military Projedliles , and the Defcription of a very 
accurate Eprouvette for Gun-powder . By Benjamin Thomp- 
fon, Efq , F. R. S. 
Read March 29, 1781. 
T HESE experiments were undertaken principally with a 
view to determine the moft advantageous fituation for the 
vent in fire-arms, and to meafure the velocities of bullets, and the 
recoil under various circumftances. I had hopes alfo of being- 
able to find out the velocity of the inflammation of gun-powder, 
and to meafure its force more accurately than had hitherto been 
done. They were begun in the month of July in the year 
Vol.LXXI. % I i? 7 8 > 
