TRACT 34.
IN GUNNERY.
379
which being too short a length to give direction to the ball,it missed the pendulum, going over and just striking thetop of the screen frame, about 21-J- inches above the lineof direction, which, though a very slender piece of wood,turned the ball up into a still higher direction, in which itstruck the bank over the pendulum, and entered it sloping,though but a little way : all which circumstances show thatthe force of the ball was but small. And even at the 9thround, when the centre of the ball was about 3 inches withinthe gun, the ball struck the pendulum 5 inches out of theline of direction. The gun was scarce ever sensibly heated.
The diameter of the balls P96 inches.
The Pendulum had been gutted, and had received a newcore. It rvas hung up in the morning of the day before yes-terday, Avhen it weighed 659 lb. And rvhen taken downthis evening it weighed only 686 lb, which is near 4 lb“ lessthan the balls and plugs ought to make it; and which 4pounds must have evaporated in the 3 days.
The plugs weighed ~ of an ounce to the inch.
The value of i, or mean point struck, 89 - 7.
All the three rounds Avith 16 oz are very doubtful, andseem to be too Ioav, from some unknown cause.
Mean velocity by the pendulum, &c.
Powder
Recoil
Veloc.
wt
ht
gun
ball
8
- 5'6
-
-
25-7 - -
1383
10
. - 6-9
-
-
28-6 - -
1417
12
- 8'3
-
-
30-0 - -
1375
14
- 9-7
-
-
32-3 - -
1333
16
- 1P0
-
-
3P8 D- -
1243 D
20
- 13-3
-
-
36-7
24
- 14-5
-
-
38-6
32
- 21-6
-
-
44-0
36
- 24-4
-
45-8
39
- 27-2
-
-
47-5