MAGNETICAL OBSERVATIONS 
739 
VARIATION of the MAGNETIC NEEDLE at Sea, with BARLOW’S PLATE attached to the COMPASS. 
Date. 
1828. 
Jan. 
Feb. 
Latitude. 
North. 
21 34 
21 27 
21 27 
21 48 
21 49 
22 02 
22 12 
22 40 
22 40 
22 43 
Longitude. 
West. 
105 29 
106 17 
106 10 
105 51 
106 01 
106 00 
105 55 
105 50 
105 58 
106 05 
Variation. 
East. 
9 10 10 
8 30 00 
9 00 00 
8 14 00 
10 13 00 
10 16 00 
7 51 00 
8 37 45 
10 24 00 
8 13 00 
8 48 15 
8 45 20 
Date. 
1828. 
Feb. 
March. 
Latitude. 
North. 
22 54 
22 50 
22 56 
22 06 
21 15 
20 50 
20 17 
19 53 
18 29 
18 17 
18 12 
Longitude. 
West. 
106 10 
106 12 
106 15 
105 53 
105 25 
1 05 40 
105 40 
105 34 
104 16 
104 00 
103 30 
Variation. 
East 
10 09 05 
8 27 30 
10 15 35 
1828. 
March. 
20 
10 
58 15 
12 00 
08 30 
8 57 40 
9 48 55 
10 03 00 
8 21 
10 47 
7 
8 
7 
Date. 
Latitude. 
North. 
16 45 
14 29 
14 22 
14 13 
13 46 
12 38 
20 
56 
39 
18 
0 34 
Longitude. 
West. 
101 00 
99 08 
99 00 
98 54 
98 56 
98 59 
98 45 
98 11 
97 37 
97 22 
99 22 
Variation. 
East. 
10 29 45 
7 47 20 
8 10 15 
9 09 20 
9 03 45 
9 08 35 
8 29 55 
8 13 50 
8 35 00 
8 54 15 
8 25 10 
VARIATION of the COMPASS observed on shore. 
Date. 
Place. 
Variation 
E. 
1825. 
July. 
Rio Janeiro . ^ 
0 ' " 
2 51 00 
3 30 45 
Mean 
3 10 52 
Oct. 
Conception 
Chili . . 4 
2 10 06 
2 27 42 
16 37 12 
16 38 00 
17 12 00 
... 
Mean 
16 49 4 
... 
do. do. 
do. 
18 17 46 
16 52 35 
Valparaiso • 
15 18 25 
15 55 00 
15 34 00 
16 44 00 
1828. 
May. 
1825. 
Dec. 
Mean 
15 52 51 
Coquimbo 
Pitcairn Island ^ 
14 24 00 
5 57 35 
6 02 10 
1826. 
Jan. 
April. 
Mean 
5 59 52 
Gambler Islands 
Otaheite 
7 08 00 
7 33 25 
Place. 
Variation. 
E. 
Instrument 
used. 
Observ 
0 ' " 
9 38 00 
No. 1. 
B. 
9 49 0 
, . 
9 41 0 
No. 2. 
9 18 00 
. 
11 10 00 
No. 1. 
Woahoo . 
11 10 10 
• • 
10 58 10 
, , 
11 00 00 
. 
10 48 10 
. . 
10 35 00 
No. 2. 
L 
10 37 00 
• 
Mean 
10 25 52 
10 40 37 
B^ 
10 33 31 
Theod. 
4 48 25 
No. 2. 
B. 
4 35 42 
* 
3 43 00 
Theod. 
4 26 00 
Petropaulski 
3 23 00 
4 31 00 
. 
4 48 00 
. 
4 30 00 
. 
V. 
4 07 00 
Gilbert. 
Mean 
4 13 18 
. 
4 57 31 
Theod. 
B^ 
At anchor in the\ 
30 05 00 
Gilbert. 
B. 
bay Good Hope. | 
do. 
29 13 00 
. 
• • 
do. 
29 06 00 
• 
• • 
Mean 
29 28 0 
5 B 
2 
used. 
Observer 
No. 1. 
No. 2. 
Gilbert. 
No. 1. 
1 . 
2 . 
Gilbert. 
No. 1. 
No. 2. 
No. 1. 
No. 1. 
2 . 
Theod. 
Theod. 
B. 
BL 
W. 
B. 
BL 
W. 
B. 
B‘. 
Date. 
1826. 
May. 
1827. 
Feb. 
July. 
1826. 
