44 2 Capt. Kater’s experiments for determining the variation 
Aiiburv Hill, at the Pendulum Station, 1818, August 18th, P. M. Q’s U. L. 
Chronometer. 
Mean 
True time 
Chronom. slow 
h. m. s. 
3.4. 7 
3.5.31 
37-34 
3.8.51 
3.6.30,7 
3.6.44,5 
13,8 
( + 45—51) 
X 2,4=— 7,2 
Level 
+ 9 
+ ii 
+ 14 
+ 11 
+ 45 
— 17 
— 12 
- 9 
—13 
—51 
Readings, &c. 
First Vernier 
Second 
Third 
Fourth 
Mean 
Level 
Index 
Observed Z. D. 
Ref. and Parall. 
Semidiam. 
True Z. D. 
29<).46.55 
40 
50 
45 
299-46.47,5 
— 7,2 
+ 18,0 
4)299.46.58,3 
- 74.56.44,6 
+ 3.24,3 
+ 16 . 6,0 
75.16.14,9 
Arbury Hill, at the Pendulum Station, August ISth, P. M. Q’s U. L. 
Level. 
Readings, &c. 
+ 14 
+ 12 
— 7 
— 9 
O / // 
First Vernier - 151.57. 5 
Second - - 56.30 
Third - - 56.35 
Fourth - - 56.45 
+ 26 
— 16 
Mean - - 151.56.43,7 
Level - - + 12,0 
Index - - + 18,0 
2)151.57-13,7 
Observed Z. D. - 73.58.36,8 
Ref. and Parall. - + 3.48,2 
Semidiam. - + 16. 6,0 
True Z. D. - 76.18.31,0 
Chronometer. 
Mean 
True time 
Chronom. slow 
h. m. s. 
3.13.48 
3.16.12 
3.15. 0 
3.15.14,8 
14,8 
<±2±^>x5.4=+Ao 
From the mean of the above observations the chronometer 
appears to be i4‘,3 too slow; the daily rate being — i', 2 6. 
