Mr. Thompson’s Experiments 
-274 
A "table of experiments , Jbewing the effetf of placing the vent in 
df event parts of the charge » 
Weight of the 
charge of pow- 
der. 
Space, occupied 
by the powder. 
j Vent from the 
[ bottom of the 
j bore. 
Velocity of the 
bullet at a me- 
dium. 
Recoil mea- 
fured upon the 
ribbon at a me- 
dium. 
Number of ex- 
periments. 
Grains. 
Inches. 
Inches. 
Ft: in a fee. 
Inches. 
165 
G 45 
0 
IC'87 
14,465 
2 
• • • 
• • • 
T nr ) 
IO82 
* 4,3 * 
9 ! 
O 
218 
J >9 
0 
1225 
* 7,93 
4 
• • • 
. . . 
G 3 
1276 
18,34 
4 
290 
2,6 
0 
1427 
22,626 
9 
0 
• • 0 
• • © 
n 3 
*493 
9 0 0 A 
3 
# • 0 
• 90 
2. .6 
1460 
23,286 
4 
0^0 
0 • • 
0 
1444 
2 3> I 35 
4 
• © 9 
• • • 
2,6 
I 4 I 3 
24,5 
9 
0 
3 IQ 
2,7 
0 
24.69 
I 
• • • 
• 0 • 
1,32 
24,95 
I 
• • • 
0 • 0 
2,65 
24,9 
I 
33 ° 
2,9 
0 
1594 
26,075 
2 
» • • 
i ,3 
1625 
26,4 
9 
• • 0 
• • 0 
2,6 
W 5 
2 5,3 
2 
4371 
3,9 
0 
1764 
0 0 0 
00,. 5 
0 
0 
• e • 
- 0 * 
2,6 
*75 1 
.32,866 
3 
By the foregoing experiments it appears, firft, that the dif- 
ference in the force of any given charge of powder which 
arifes from the particular fituation of the vent is extremely 
final I. 
With 165 grains of powder, and the vent at 6, the velocity 
of the bullet at a mean of two experiments (viz. the 20th 
and 2 1 ft) was 1087 feet in a fecond; and with the fame charge, 
and the vent at 1,32 inches, the velocity at a mean of the 
,&ad ? 23d, and 24th experiments, was 1082 feet in a fecond; 
the 
