LIEUT. CLERK’S REPORT: ELEMENTS OF REDUCTION. 
365 
♦ 
“ The angles of deflection observed at King George’s Sound are as follows : — 
Def. N. 
w= 2-779. 
Def. S. 
u>=2-821. 
Mag. N and S. 
m>=3’909. 
Mag. N. 
w = 2-875. 
Mag. S. 
2895. 
Weight 
1 grain. 
Weight 
1 1 grain. 
Weight 
2 grains. 
Weight 
grains. 
Weight 
3 grains. 
o / 
33 11 
33 32 
50 24 
34 30 
o / 
34 34 
o / 
10 44 
17 16 
22 55 
o / 
28 18 
35 10 
“ Employing the values of v and iv (I being = 1'6S8), we get formulae for calculating 
the intensities, viz. — 
Def. N .... I' = -3325 cosec v' .w'. 
Def. S I' = -3306 cosec v ' . w\ 
Mag. N and S I' =-3327 cosec v' .w 1 . 
Mag. N .... I'=-3326 cosec v'.w'. 
Mag. S .... I' = -3308 cosec v' .w'. 
Weight 1 grain . . I'= *3 144 cosec v' . 
Weight 1|- grain. . I' = *50 10 cosec v'. 
Weight 2 grains . . I'=*6573 cosec v' . 
Weight 2^ grains . I'= *8003 cosec v' . 
Weight 3 grains . . I'= '9722 cosec v'. 
Comparing observations made at sea near the Cape with those given by the other 
needle, the deflectors of this apparatus do not appear to have lost magnetism. 
‘‘From King George’s Sound to the Cape, needle B was mounted, the same de- 
flectors and weights being used as with needle A. The Cape of Good Hope has been 
taken as the base station in this case, the intensity having been observed there on the 
return of the Expedition. 
“The table of equivalent weights is given below. 
Def. N. 
Def. S. 
Mag. N and S. 
Mag. N. 
Mag. S. 
v\ 
v/. 
v\ 
w'. 
V. 
w'. 
V 
w'. 
v'. 
w '. 
29 
1-794 
35 
2-104 
0 
50 
2-763 
o 
31 
1-891 
36 
2-174 
30 
1-782 
36 
2-076 
51 
2-701 
32 
1-862 
37 
2-122 
31 
1-765 
37 
2-046 
52 
2-638 
33 
1-833 
38 
2-069 
32 
1-748 
38 
2-015 
53 
2-576 
34 
1-804 
39 
2-012 
33 
1-734 
39 
1-986 
54 
2-513 
35 
1-773 
40 
1-954 
34 
1-719 
40 
1-956 
55 
2-457 
36 
1-741 
41 
1-903 
35 
1-697 
41 
1-927 
56 
2-401 
37 
1-705 
42 
1-851 
36 
1-675 
42 
1-898 
57 
2-345 
38 
1-669 
43 
1-801 
37 
1-657 
43 
1-865 
58 
2-288 
39 
1-635 
44 
1-751 
38 
1-638 
44 
1-832 
59 
2-247 
40 
1-600 
45 
1-707 
39 
1-619 
45 
1-799 
60 
2-203 
41 
1-563 
46 
1-663 
40 
1-600 
46 
1-766 
61 
2-167 
42 
1-525 
47 
1-626 
41 
1-582 
47 
1-740 
62 
2-110 
43 
1-494 
48 
1-588 
42 
1-56.3 
48 
1-713 
63 
2-071 
44 
1-463 
43 
1-541 
49 
1-684 
64 
2-032 
45 
1-443 
44 
1-519 
50 
1-654 
65 
1-996 
45 
1-491 
66 
1-960 
67 
1-927 
“The followingare the angles of deflection on three separate days at the Magnetic 
Observatory, Cape of Good Hope : — 
Def. N. 
w= 1-500. 
Def. S. 
w= 1-659. 
Mag. N and S. 
w= 1-953. 
Mag. N. 
w= 1-480. 
Mag. S. 
w — 1-615. 
Weight 
1 grain. 
Weight 
1 4 grain. 
Weight 
2 grains. 
44 32 
49 48 
66 02 
43 21 
o / 
47 13 
28 00 
44 10 
_ ° < 
69 31 
45 00 
49 59 
66 20 
43 45 
47 23 
44 33 
49 42 
66 16 
43 15 
47 20 
2S 26 
44 16 
69 15 
44 42 
49 50 
66 13 
43 27 
47 19 
28 13 
44 13 
69 23 
3 B 
MDCCCXLVI. 
