experiments made with an invariable pendulum , $c. 
323 
From the above we have the following results. 
Vibrations of the Pendulum at Paramatta. ( 2 d. Series.) 
Date. 
Barometer. 
Thermo- 
meter. 
Vibrations in 
24 hours. 
Correction 
for Tem- 
perature. 
Vibrations in 
24 hours at 
60 degrees. 
Aug. 31 
Sept. 1 
2 
3 
4 
Inches. 
29.55 
29,87 
29,71 
29,80 
29,74 
29,64 
29.56 
O 
58, 0 
57,25 
55.15 
60, 2 
57,25 
58,85 
62.15 
86016,36 
86016,20 
86017,18 
86016,32 
86017,00 
86016,71 
86015,21 
—0,85 
— 1,16 
— 2,06 
+ 0,09 
— 1,16 
— 0,47 
+ 0,89 
86015,51 
86015,04 
86015,13 
86016,41 
86015,84 
86016,24 
86016,10 
Mean 
29,75 
58,41 
86015,75 
y 
The barometer being at 29,75 inches, and the thermometer 
at 58,41 during the experiments, we have 6,46 for the buoy- 
ancy of the atmosphere, which, added to the mean number 
of vibrations, gives 86022,21 for the number of vibrations 
which would be made by the pendulum in a mean solar day 
at 6o°, and in a vacuum. 
The height of the station at Paramatta, above mean high 
water, is stated by Sir T. Brisbane to be seventy-seven feet, 
and that of the station at London being eighty-three feet 
above low water, it could only introduce error to attempt any 
correction for a difference which has not yet been accurately 
ascertained. 
If the number of vibrations resulting from Sir Thomas 
Brisbane’s experiments at Paramatta be compared with the 
mean number of vibrations made by the pendulum at London, 
we shall have 39,07 696 inches for the length of the pendulum 
vibrating seconds at Paramatta ; ,0052704 for the diminution 
of gravity from the pole to the equator ; and ■ for the 
