20 
Lieutenant Foster’s account of 
Vibrations of the Pendulum at the Royal Observatory at 
Greenwich. 
The Clock making 86396,71 vibrations at a mean rate in a mean solar day, 
April 1824. 
Date. 
Barom. 
Therm. 
d . 
6 0 * 
0) 0 
H 
fl -n 
0 a 
Vibrations of Pendulum in 
24 h. corrected for Arc by 
<2 S 
.2 1 
Vibrations in 24 hours at 
temperature of 50°. 
s . 
3 
Disappear- 
ance. 
Mean ofDisap. 
and Re-app. 
U CL 
£ a 
Disappear- 
ance, 
Mean ofDisap. 
and Re-ap, 
20th P. M. 
Inches. 
30,20 
O 
59,0 
O 
9,0 
86149,08 
86149,19 
vib. 
+ 3,81 
86152,89 
86153,00 
2 1 st A. M. 
30,00 
S 5 , 6 
5 , 6 
86150,70 
86150,85 
+ 2,37 
86153,07 
86153,22 
P. M. 
29,88 
59,2 
9,2 
86148,99 
86149,1 1 
+ 3,89 
86152,88 
86153,00 
22d A. M. 
29,82 
56,6 
6,6 
86150,05 
86150,13 
+ 2,79 
86152,84 
86152,92 
P. M. 
29,86 
60,2 
10,2 
86148,28 
86148,40 
+ 4,3 » 
86152,59 
86152,71 
23d A. M. 
2 9 > 39 
53,8 
3,8 
86150,97 
86151,06 
+ I,6l 
86152,58 
86152,67 
P. M. 
29,14 
52,8 
2,8 
86151,35 
86151,51 
+ 1,18 
86152,53 
86152,69 
24th A.M. 
29,90 
S 3 ,o 
3 ,o 
86151,13 
86151,29 
+ 1,27 
86152,40 
86152,5 6 
P.M. 
30,01 
56,9 
6,9 
86149,51 
86149,68 
+ 2,29 
86152,43 
86152,60 
25th A. M. 
30,05 
53 A 
3 * 1 
86151,50 
86151,62 
+ i* 3 * 
86152,81 
86152,93 
Mean . . 
29,82 
56,0 
86152,70 
86152,83 
