400 Capt. Kater’s experiments for determining the variation 
and level, and thus to introduce error. In the usual con- 
struction the level may be clamped to the circle, and then it 
moves with it without any risk of derangement. This con- 
struction was indispensable, in order that the instrument 
might be used for taking terrestrial angles, and it is to this, 
perhaps originally accidental circumstance, that the repeating 
circle is indebted for its very near approach to perfection. 
After I had restored the instrument to its former state, the 
following observations were made. 
Clifton, 8th October, 1 8 1 8. Barometer 29,60 inches, thermometer 46°. Chrono- 
meter too slow 23,9. Pole star on the meridian by the chronometer u. h 49n>.is. 
Chronometer. 
h. m. s. 
1 1.22. 10 
11.25.35 
1 1.30.20 
1 i. 33. 12 
1 1.37.1° 
1 1.40. 12 
11.44. 7 
1 1.48.10 
u.53.3 0 
11.57. c 
12. 0.10 
12. 3. 8 
12. 6.37 
12. 9.23 
Level. 
+ 2 3 
-f 26 
+ 2 4 
+ 2 4 
+ 2 ' 
+ 2 4 
-J- 22 
+ 2 4 
+ 2 4 
-f 26 
+ 2 9 
22 
+ 2 7 
+ 2 3 
+ 339 
24 
2 3 
24 
24 
27 
25 
28 
25 
25 
24 
J 9 
28 
22 
28 
—346 
Time from 
the 
meridian. 
m. s. 
26.5 1 
23.26 
1841 
I 5-49 
11. 51 
8 49 
4-54 
0.51 
4.29 
7- 59 
11. 9 
H- 7 
1 7-3 6 
20.22 
N. v. Sines. 
6855 
5223 
3321 
2380 
1336 
°74° 
0229 
0007 
0191 
0607 
1183 
1 896 
2947 
394° 
2204 
(+339-346) x?>4= _- + con for the leTel 
Readings, &c. 
Const. Log. 
Log. 2204 ( + 4) 
Correct.— -1 3", 7 8 Log. 
3.7959304 
7.3432116 
1.1391420 
1 st Vernier 
Second 
Third 
Fourth 
Mean 
Level 
Index 
Observed Z. D. 
Refract. 
Correct. 
zr'Q. 
<Z-Z') 
True Z. D. 
128.13. 0 
12.30 
12.25 
I2 -3S 
- 128.12.37,5 
-f 360. o. o 
- — 8,4 
- -J- 18,0 
14) 488.12.47,1 
34.52.20,51 
+ 4°>5 2 
— 13,78 
— c,o8 
+ 0,30 
■ 34'5 2 -47»47 
Mean P. D. for 1818 -f 1.39.44,15 
Precession, See. - — 14.34 
Co. Lat. - 
Lat. of Clifton 
36.32.17,28 
53.27.42,72 
