LIEUT.-COLONEL SABINE ON TERRESTRIAL MAGNETISM. 
125 
Part II. contains a condensed abstract of the observations with Nos. 5, 6, 7, 8, 9, 1 1, 
12 and 13, between March 1839 and April 1840, more detailed particulars of which 
have been already given in Table V. of No. II. of these Contributions. Part III. com- 
prises the whole remainder of the observations from May 1840 at Rarotonga Island 
to December 1842 at Woolwich. The manner in which the values of the horizontal 
force in the final column of Parts II. and III. have been computed, has been already 
explained. 
Table II. contains the observations of the Inclination subsequent to March 1840, 
made with the same six-inch Inclinometer, by Robinson, employed at the earlier sta- 
tions : this Table is a continuation of Table IX. in No. II. of these Contributions. 
The Declinations inserted in the general table were observed with a nine-inch alti- 
titude and azimuth instrument by Cary, having a four-inch magnetic needle attached 
to it. 
The general table. Table III., comprises in one view, the Declination, Inclination, 
horizontal and total Intensity, resulting from the whole of the observations, and is 
the best evidence, especially to those who are familiar with the practical details of 
such observations, of the amount of obligation which magnetical science owes to Sir 
Edward Belcher, and to the officers of the Royal Navy employed under his direc- 
tion. 
Table I.— Part I. 
Abstract of Observations with the Intensity Needles between March 1837 and March 
1839 ; in these observations the commencing semi-arc was 40°. 
Station. 
1837. 
Needle. 
No. of 
Time 
Thermo- 
Chronometer 
Final 
Corrected 
Horizontal Intensity] 
observa- 
of vibra- 
meter. 
rate. 
semi-arc. 
time, 
Panama = 7*743. 
tions. 
tion. 
75 J Fahr. 
r 
March 10. 
5 
2 
s 
472-7 
O 
79 
s 
L. 1-1 
o 
14 
s 
467-8 
Panama . . < 
10. 
6 
2 
512-5 
76 
L. 1-1 
14 
507-4 
12. 
7 
1 
522-7 
71 
L. 1-1 
4 
531-3 
12. 
8 
1 
470-4 
76 
L. 1-1 
7 
468-1 
Fort Etches < 
August 28. 
28. 
5 
6 
1 
1 
736-7 
792-4 
50 
50 
L. 8-6 
L. 8-6 
5 
8 
737-9 
794-2 
3-13' 
3-16 j 
> 3-15 
1838. 
Acapulco . . - 
' 
January 17- 
17- 
6 
7 
1 
1 
508-1 
530-7 
88 
91 
L. 5-4 
L. 5-4 
13 
3 
501-4 
529-2 
TJ4 
GO OO 
> 7 - 9l 
r 
June 20 & 21. 
5 
80 
487-1 
68 
L. 2-0 
14 
483-1 
7-31" 
Callao ....<; 
25. 
6 
1 
525-0 
79 
L. 2-0 
13 
519-2 
7-41 
>7-37 
27. 
7 
1 
546-1 
72 
L. 2-0 
5 
544-3 
7-44 
27. 
8 
1 
483-8 
70 
L. 2-0 
6-5 
481-8 
7-32 
Puna Island, 
r 
Sept. 3. 
5 
90 
476-1 
78 
L. 1-4 
14 
471-2 
7-69 
7-74 
Guayaquil 
: 
17-23. 
6 
7 
513-2 
89 
L. 1-4 
13 
505-9 
7-80 J 
r 
October 28. 
5 
2 
475-3 
82 
Not recorded. 
14 
470-0 
Panama . . < 
28. 
6 
2 
514-6 
83 
Not recorded. 
13 
508-3 
28. 
7 
1 
536-8 
83 
Not recorded. 
4 
535-1 
28. 
8 
1 
471-4 
83 
Not recorded. 
6 
469-1 
1839. 
March 16 . 
5 
2 
476-2 
85 
L. 2-1 
14 
470-7 
16. 
7 
2 
536-1 
84 
L. 2-1 
3-5 
534-5 
16. 
8 
2 
471-4 
87 
L. 2-1 
5 
469-4 
s 2 
