PHILOSOPHICAL 
TRANSACTIONS. 
XV. New Experiments upon Gun-powder , with occajional 05 - 
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 circumflances. 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 
Yol. LXXI. 2 I 17789 
