147 
the length of the pendulum at Madras. 
The correction for the arc of vibration was ascertained by 
multiplying the square of the mean arc by l ,6385. The cor- 
rection for temperature was found as follows : the mean of 
the thermometer at the beginning and middle of the observa- 
tions was taken, and that of the middle and end ; which gave 
five heights, one for each observation ; the mean of the first 
and second, of the second and third, and so on in succession 
was taken, which gave four mean heights ; the difference 
between each of these and 70° was multiplied by 0,423, the 
part of a vibration due to each degree of the thermometer, as 
furnished by Captain Kater, and the required correction was 
obtained. 
The rate of the clock was found as before mentioned. The 
following shows the daily rate of the transit clock, in the in- 
terval during which the observations were taken ; and fur- 
nishes a satisfactory example of the good performance of this 
standard for finding the rate of the other clock. 
Rate of the Transit Clock. 
March 22 
— 0,25 
March 29 
+ 0,09 
23 
+ 0,13 
3 ° 
- + 0,05 
24 
wi 
0 
d 
1 
• 
3 i 
• 
I 
0 
0 
2 5 
+ 0,23 
April 1 
+ 0,02 
26 
+ 0,10 
2 
0,08 
27 
+ 0,15 
3 
+ 0,05 
28 
+ 0,20 
4 
— 0,04 
