experiments made with an invariable pendulum. 
69 
Vibrations of the Pendulum at the Royal Observatory at Greenwich, 
November 1825. 
The Clock making 86398,13 vibrations in a mean solar day at a mean rate. 
Date. 
Barom. 
Ther. 
Diff. 
Temp. 
& 50 
Vibra. in 24 h. cor. for Arc by 
Correction 
for Temp. 
Vibra. of pend, in 24 h. at 
temp, of 50 ° by 
Disappearance. 
Mean of Disap. 
and Re-ap. 
Disappearance. 
Mean of Disap. 
and Re-ap. 
Nov. 7th A.M. 
_ P.M. 
8 A.M. 
- P.M. 
9 A.M. 
- P.M. 
10 A.M. 
_ P.M. 
11 A.M. 
- P.M. 
In :hes. 
29.H5 
29.126 
29.200 
29.058 
* 4-973 
29.023 
28.613 
28.597 
29.280 
29.312 
0 
44.11 
46. 1 3 
41.10 
44.12 
45.69 
47 - 5 1 
44.25 
45.20 
42.39 
44-32 
0 
5.89 
3- 87 
8.90 
5.88 
4 - 3 i 
2.49 
5 - 75 
4.80 
7.41 
5.68 
86156,386 
86155,521 
86157,150 
86155,792 
86154,692 
86154,159 
86154,868 
86154,414 
86155,451 
86154,899 
86156,519 
86155,636 
86157,263 
86155,887 
86154,84 6 
86154,275 
86154,983 
86154,588 
86155,604 
86153,091 
vib. 
— 2.491 
— I.637 
— 3-765 
— 2.487 
— I.823 
— I.053 
— 2.432 
— 2.030 
— 3-134 
— 2.403 
86153,895 
86153,884 
86153,385 
86153,305 
86152,869 
86153,106 
86152,436 
86152,384 
86152,317 
86152,49 6 
86154,028 
86153,999 
86153,498 
86153,400 
86153,023 
86153,222 
86152,551 
86152,558 
86152,470 
86152,688 
Mean. 
29.297 
44.50 
86153,008 
86153,144 
Results. 
From 
To 
Correct number of vibrations of 
pend, in a mean solar day. 
Disappearances. 
I Mean of Disap, 
and Re-ap. 
Nov. 7th A. M. 
8th A. M. 
9th A. M. 
10th A. M. 
Nov. 8th P. M. 
9th P. M. 
10th P. M. 
nth P. M. 
9th P. M. 
10th P. M. 
1 1 th P. M. 
10th P. M. 
nth P. M. 
n th P. M. 
86152,867 
86153,017 
86152,978 
86153,008 
86153,126 
86153,024 
86153,037 
86152,949 
86153,001 
86152,958 
86152,981 
86153,138 
86 153,105 
86153 , J 44 
86153,246 
86153,152 
86153,176 
86153,088 
86153,152 
86153,117 
Mean 
Correction for buoyancy 
elevation 
Final No. of vibra. in vacuo at the"l 
level of the sea, temp. 50 0 . (Fah.) J 
86152,996 
+ 6,041 
+ 0,450 
86153,130 
+ 6,041 
+ 0,450 
86159,487 
86159,621 
