Gun-powdery &c; 275- 
the difference, equal five feet in a fecond, is lefs .than what 
occurred in a repetition of the fame experiment. 
With 218 grains of powder, and the vent at o, the velocity 
at a mean in the 40th, 41ft, 43d, and 47th experiments, 
was at the rate of 1225 feet in a fecond; and with the fame 
charge, and the vent at 1,3, the velocity was 1276 feet in a 
fecond at a mean of four experiments, viz., the 43d, 44th, 
45th, and 46th. 
In the firfl: fet of experiments, with 290 grains of powder*, 
the velocities were, 
Vent at o. 
Vent at 1,3, 
Vent at 2,6. 
1414 
1476 
I5°2 
1455 - 
1 J20- 
X450 
1412 
1483 
1 433 
1454 
3)4281 
3)4479 
4)5839 
1427 
1 493 
I46O" 
Means 
See the experiments from N° 48. to N° 57. inclufive^ 
Ih the fecond fet the velocities were*.’ 
Means 
Vent at 0. 
Vent at 2,6. 
1419 
1438 
I46O' 
1423 
1462 
Co 
vi 
00 
1436 
4)5777 
3 > 4239 ) 
1444 
I 4 I 3 
See the experiments from N? 109, to N° 115. inclufive. 
And 
