378 Capt. Kater/s experiments for determining the variation 
at 7o°,5 the correction for the buoyancy of the atmosphere is 
5 , 9 *- 
The height of the pendulum above the level of the sea was 
83 feet, the correction for which is 0,34, x — 0,22. 
These corrections being applied, we have 86061,4,9 vibra- 
tions in a mean solar day, at the temperature of 62° in vacuo, 
and at the level of the sea. 
Various causes prevented me from repeating my experi- 
ments in London, until the month of March, when the follow- 
ing results were obtained, the observations on which they are 
founded being detailed in the Appendix. 
Vibrations of the Pendulum at London. — 2nd Series. 
Date. 
1819 . 
Barometer. 
Thermom. 
Vibrations 
in 24 hours. 
Correction 
for 
Temp. 
Correct Vibrations in 
a mean solar day, 
in vacuo at 62 9 
March 
8 
30,10 
O 
50,0 
86o6o,I 2 
5,08 
86055,04 
9 
30,1° 
50,1 
86060,21 
5>°3 
86055,18 
l S 
3 °>H 
51,8 
86059,41 
4,32 
86055,09 
16 
30,00 
5 2 >7 
86058,98 
3,93 
86055,05 
17 
30,10 
53,5 
86058,92 
3,60 
86055,32 
S 18 
3°,2I 
52,8 
86058,93 
3,89 
86055,04 
Mean 
30,11 
00 
86055,12 
The correction for the buoyancy of the atmosphere is 6,18, 
and that for the height above the level of the sea, 0,22. We 
have therefore 86061,52 for the number of vibrations at 62° 
in vacuo, and at the level of the sea. 
So very near an agreement with my former observations, 
after an allowance for a difference of temperature amounting 
to 18*, 7 I could scarcely have dared to hope for, and it 
afforded me a most satisfactory assurance, not only that the 
