1G2 
MR. A. W. RtiCKER AND DR. T. E. THORPE ON A MAGNETIC 
Inclination. 
Date. 
Needle. 
Observer. 
Dip Circle. 
G.M.T. 
0. 
00- 
July 17, 1881 . 
1 
R. 
74 
h. 
15 
in. 
38 
6°7 36-0 
6"7 34-8 
„ 18. 
1 
T. 
74 
12 
9 
67 3.5-7 
67 34-5 
2 
T. 
74 
12 
38 
67 36-0 
67 34-8 
„ IT „ . . 
1 
R. 
74 
12 
12 
67 36-7 
67 35-5 
2 
R. 
74 
12 
47 
67 36-1 
67 34-9 
September 30,1887 
1 
R. 
74 
16 
43 
67 35-4 
67 36-8 
2 
R. 
74 
17 
10 
67 .34-2 
67 35-6 
October 11, 1887 . 
1 
T. 
83 
14 
33 
67 34-2 
67 35-6 
2 
T. 
83 
15 
7 
67 35-4 
67 36-8 
„ 13. „ . 
1 
T. 
83 
14 
27 
67 35-0 
67 36-4 
2 
T. 
83 
15 
0 
67 35-0 
67 .36-4 
„ 18, „ . 
1 
T. 
83 
13 
52 
67 34-2 
67 35-6 
2 
T. 
83 
14 
28 
67 34-3 
67 35-7 
„ 19, „ . 
1 
R. 
74 
13 
38 
67 35-3 
67 36'7 
2 
R. 
74 
14 
2 
67 34-5 
67 35-9 
Mean 
67 35-8 
In the following Table tlie values for January 1,1886, deduced above from the survey 
instruments, are given in Column I. In Column II. are the mean differences between 
the survey and Kew instruments (see p. 58), and hence in Column III. the Kew 
(calculated) values are deduced. In Column IV. are the published elements for that 
epoch (‘Roy. Soc. Proc.,’vol. 41, 1887, p. 416), the Declination being’ corrected for 
diurnal variation. 
I. 
II. 
III. 
IV. 
18° 14'-4 
1-8089 
67“ 35'-8 
+ 2'-5 
- 0-0029 
A 2'-7 
18° 16'-9 
1-8060 
67° 38'-5 
18° 16'-3 
1-8093 
67° 37'-4 
The aofreement between Columns III. and IV. is satisfactoi’v in the cases of the 
Declination and Dip. In that of the Horizontal Force the actual value in January, 
1886, seems to have been rather high. As a good deal will hereafter be said about 
the relative values of the elements at Kew and Greenwich, and as we have not 
compared our instruments wdth those at Greenwich, it has been thought better to 
treat both these observatories in the same way, and therefore to use the numbers in 
Column IV. as the Kew values. 
