20
NEW EXPERIMENTS
TRACT 34,
79. 'Tuesday, September 21, 1784 ; from 10'- till I-§-,The weather moderately warm.
N?
Pow-
der.
Vibration of
Point
struck
1 Plugs |
Values of
Veloc.
feet
gun
pend
p
g
n
oz
inches
inc
lb
inches
ball
1
4
166
2
4
457
132
89-7
5
683-0
76-66
40-28
1125
3
4
451
132
91-3
4
684-1
76-68
40-28
1107
4
4
458
136
91-5
4
685-2
76-70
40-28
1140
5
6
157
88-9
4
686-3
76-72
40-28
1357
6
6
613
162
91-0
4
687-5
76-74
40-28
1371
7
6
591
153
90-1
4
688-6
76-76
40-28
1310
8
6
617
162
90-2
5
6S9-7
76-78
40-28
1388
9
8
163
89-6
5
690-8
76-80
40-27
1420
10
8
168
88-6
4
1 691*9
76-82
40-27
1471
The ball’s diameter, 1*965 inches, and weight 16oz 12 dr.
The Gun was n° l, without any of the leaden weights.The gun itself now weighs only 179 lb, as it has beenlightened 111 lb, by turning it down, to try if the velocityof the bail would be any less by making the gun lighter:but no difference appears, as the iron work is 205, the gunand iron together this day weigh 384 lb.
80. The Pendulum as left yesterday, except that it hadreceived a strengthening strap of iron, weighing 7 lb lS^oz,which, reduced to its centre of gravity, is placed at 79inches below the axis. With this strap it weighed thismorning, before the experiments commenced, 683 lb ; whichis 6*2 lb less than it ought to be, by adding all the balls andplugs to the first weight; of which 6*2 lb difference, about1*6 lb is for waste of the leaden facing, and the rest 4-6 lbis probably by evaporation: and as the time the pendulumhas hung up is ] 1 days, the rate of evaporation is about j.of a pound per day. The 6‘2 lb loss is divided equallyamong all the 32 experiments that have been made.