26 
LIEUT.-COLONEL SABINE ON TERRESTRIAL MAGNETISM. 
determinations, the “ corrections for epoch” and the uncertainties consequent there- 
upon, bear to the probable amount of the combined instrumental differences and ob- 
servation errors of independent careful observers ; and, consequently, the importance 
of the synchronism so much insisted upon, of the observations which are to concur 
in determining the magnetic state of the globe at the present period. 
Inclination . — The inclinations contained in Table IX. were observed with a six- 
inch instrument by Robinson, with a needle by the same artist. The poles of the 
needle were reversed on every occasion, and the observations were repeated in the 
eight different positions of the circle and needle. Usually five repetitions were made 
in each position, and the arcs at both ends of the needle being read, the inclinations 
in the Table are generally a mean of eighty readings. 
Table IX. — Observations of the Inclination. 
Date. 
Poles. 
Inclination. 
Remarks. 
Direct. 
Reversed. 
1837. 
March 8 
March 8 
30 
30 
58'8 
54-6 
32 
32 
53-2 
51-0 
31 
31 
51- 0" 
52- 8 
3i 
51-9 
Near the Ruins of the Con- 
vent of San Francisco. 
March 20 
March 22 
30 
30 
27-5 
08-5 
32 
32 
01-5 
10 
31 
31 
14-5 
09-3 
3, 
11-9 
July 20 and 24 . 
40 
43-4 
42 
27-6 
41 
35*1 
August 26 and 28 
76 
02-2 
76 
03-6 
76 
02-9 
September 20 . . 
75 
47-5 
75 
53-8 
75 
50‘6~ 
75 
51-5 
Observation Island. 
September 22 . . 
75 
49-1 
75 
55-5 
75 
52-3 
December 21 
December 22 . . 
44 
44 
20-2 
12-8 
46 
46 
30-2 
34-0 
45 
45 
25-2 
23-4 
j> 45 
24-3 
Palm Island. 
December 22 . . 
43 
59-2 
45 
26-3 
44 
42-7 
Beach near the Arsenal. 
December 29 
61 
18-9 
62 
28-7 
61 
53-8 
Yerba Buena. 
1838. 
January 18 .... 
36 
51-2 
39 
03-7 
37 
57-4 
Near the Castle. 
March 19 and 21 
33 
13-6 
36 
00-2 
34 
36-9 
Cardon Island. 
April 6 
22 
29-2 
24 
36-9 
23 
33-2 
June 1 9 and 23 
— 4 
20-9 
-8 
07-7 
- 6 
14-3 
Plaza de los Muertes. 
September 17 . . 
8 
09*4 
9 
1M 
8 
40-2 
Punta Arena. 
September 20 . . 
8 
58-1 
10 
15-8 
9 
36-9 
Town of Puna. 
September 21 . . 
September 24 . . 
8 
8 
22*3 
10-5 
10 
9 
27-9 
31*2 
9 
8 
25-1 ] 
50*9 j 
9 
08-0 
P l Spanola. 
1839. 
March 7 
21 
26-6 
24 
24-9 
22 
55-7 
June 1 
40 
24-9 
42 
15-0 
41 
19-9] 
June 6 
40 
12-5 
42 
09-7 
41 
1M 
f 41 
16-8 
June 7 
40 
36-2 
42 
02-6 
41 
19-4 j 
July 7 
72 
28-1 
72 
57-6 
72 
42-9 
Near P 1 Greville. 
July 19 
75 
43-4 
75 
54-9 
75 
49-1 
September 13 . . 
69 
27-5 
69 
26-2 
69 
26-9 
August 12 .... 
69 
15-9 
69 
23-6 
69 
19-81 
69 
22-2 
August 12 .... 
69 
20-2 
69 
28-9 
69 
24-6 
September 25 . . 
62 
50-6 
62 
56-2 
62 
53-4 
On the Sandy Neck. 
September 30 . . 
61 
50-2 
62 
16-0 
62 
°3-n 
September 30 . . 
61 
37-1 
62 
16-0 
61 
5b’b 
October 1 . . . . 
61 
52-3 
62 
25-7 
62 
09-0 
> 62 
05-0 
October 1 .... 
6l 
52-3 
62 
22-9 
62 
07-6 
October 2 ... . 
61 
50-2 
62 
25-7 
62 
08-0 j 
Station. 
Panama | 
Magnetic Island | 
Oahu 
Port Etches 
Sitka | 
San Bias 
San Francisco. . . . 
Acapulco 
Realejo 
Cocos Island .... 
Callao 
Puna Island 
(Guayaquil) . . 
Cocos Island .... 
Oahu / 
Kodiack 
Sitka 
Baker’s Bay 
Fort Vancouver | 
Port Bodega . 
San Francisco . 
