upon Gun-powder, &c. 295 
Vent at o. Vent at 1,3. 
f 40th exp. was 18, and in the 43d exp. it was 18,3 
'The re- j - *7.7* ' 44th * i8 >35 
coil in the j 4 2d - 17,91 - 45 th - 1 ^^35 
^ 47 tli - 8,i - 46th - 18,35 
4) 7 1 ’ 7 2 4)73,35 
Means = 17,93 and 18,34 
And in the 728 and 73d experiments the recoil, with the 
fame charge without a bullet, was 8,72, and 8,47 7= 8,595 at 
a medium, the velocities therefore turn out, 
Vent at o. Vent at 1,3. 
By the recoil 1105 - 1133 
inflead of 1225 and 1 276 as they were fhewn by the pend. 
The difference .120 and 1 23 feet in a fecond amounts to near 
one twelfth part of the whole velocity. 
This difference is undoubtedly owing to the recoil without a 
bullet being taken too great'; for it is not only greater than it 
ought to be, in order that the velocities of the bullets may 
come out right; but it is confderably greater in proportion 
than the recoil with .any other charge. 
Thus, with 145 grains of powder the recoil was .4,4 
with 165 grains ~ - it was 5,55 
290 grains - - - 1.0,66 
33° grains - - - 12,7 
,and with 43 7 1 grains - ~ - it was 17,9 
And if the recoil with 218 grains is determined from thefe 
numbers by interpolation, it comes out’ 7,5 ; and with that 
R r 2 value 
( 
