OF A PENDULUM AT GREENWICH AND LONDON. 
85 
In May the temperature in the room assigned by the Astronomer Royal for 
pendulum experiments, which is the western half of the quadrant room, having 
arrived nearly at the same height as during the experiments in London, a cor- 
responding series was made at Greenwich on the 15th, 17th, 18th, and 19th of 
May, and 5th of June. The clock employed was one belonging to the obser- 
vatory, made by Graham, and was fixed against the south wall : its rate was 
supplied by Mr. Thomas Glanville Taylor, assistant at the Royal Observatory, 
by comparisons with the Greenwich transit clock, accomplished in the manner 
described in the memorandum B. annexed at the close of the paper. I am also 
indebted to Mr. Taylor for his zealous cooperation in these and the subse- 
quent experiments at Greenwich : the observations made by him are distin- 
guished by his name in Tables C. and F : the abstract of the results in Table 
C. is as follows : 
Greenwich ; May and June 1828 ; Experiments with Pendulum 12. 
May 15. 
Barom. 
29.765 .... 
Therm. 
. 60.07 • 
Vibrations at 62°. 
.... 85964.31 
15. 
29.755 .... 
. 61.15 . 
.... 85964.52 
17. 
29.705 .... 
. 59.70 . 
.... 85963.91 
17. 
29.715 .... 
. 60.68 . 
.... 85964.14 
17. 
29.700 .... 
. 61.32 . 
.... 85964.10 
18. 
29.695 .... 
. 59.28 . 
.... 85963.91 
18. 
29.715 .... 
. 60.05 . 
.... 85963.85 
18. 
29.705 .... 
. 59.77 • 
.... 85963.80 
19. 
29.710 .... 
. 57-85 . 
.... 85963.90 
19. 
29.710 .... 
. 58.70 . 
.... 85963.90 
19. 
29.700 .... 
. 59.00 . 
.... 85964.04 
June 5. 
29.335 . . . . 
. 54.92 . 
.... 85964.71 
5. 
29.360 .... 
. 55.75 . 
.... 85964.64 
5. 
29.385 .... 
. 56.65 . 
.... 85964.70 
29.639 .... 
. 58.92 . 
.... 85964.17 
The height of the barometer, reduced to 32°, and corrected for capillary 
action, -f- 0.0 19, (being the amount assigned by Mr. Daniell for capillary de- 
pression in a boiled tube of 0.26 inch, diameter,) is 29.580. 
The mean result is 85964.17 vibrations in a mean solar day, the pendulum 
