86 
MR. AIRY ON THE OBSERVED DEVIATIONS OF THE COMPASS 
Table of Polar-Magnet-Deviations, 
Apparent Azimuth from Neutral 
Position 
in points and decimals. 
Modulus. 
• 
10 
• 
11 
• 
12 
•13 
14 
•15 
•16 
17 
18 
19 
•20 
Corr espondlng Polar-Magnet-Deviation, 
in degrees and minutes. 
4* 
+ 
- 
- 
p 
P 
P 
P 
O 
/ 
0 
/ 
O 
/ 
O 
y 
o 
/ 
O 
/ 
o 
y 
O 
/ 
O 
y 
o 
y 
O 
/ 
0-0 
16-0 
16*0 
32-0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0-1 
15-9 
16-1 
31-9 
0 
7 
0 
8 
0 
9 
0 
9 
0 
10 
0 
10 
0 
11 
0 
12 
0 
12 
0 
13 
0 
14 
0-2 
15-8 
16*2 
31-8 
0 
14 
0 
16 
0 
17 
0 
18 
0 
19 
0 
20 
0 
22 
0 
23 
0 
24 
0 
26 
0 27 
0-3 
15-7 
16-3 
31-7 
0 
21 
0 
23 
0 
25 
0 
27 
0 
29 
0 
31 
0 
33 
0 
35 
0 
36 
0 
39 
0 
41 
0-4 
15-6 
16-4 
31*6 
0 
27 
0 
30 
0 
33 
0 
36 
0 
39 
0 
41 
0 
44 
0 
47 
0 
49 
0 
52 
0 
54 
0-5 
15-5 
16'3 
31-5 
0 
34 
0 
38 
0 
41 
0 
45 
0 
48 
0 
51 
0 
54 
0 
58 
1 
1 
1 
5 
1 
8 
0-6 
15-4 
16-6 
31-4 
0 
40 
0 
45 
0 
49 
0 
53 
0 
57 
1 
1 
1 
5 
1 
9 
1 
13 
1 
17 
1 
21 
0-7 
15-3 
16-7 
31-3 
0 
47 
0 
52 
0 
56 
1 
1 
1 
6 
1 
11 
1 
16 
1 
21 
1 
25 
1 
30 
1 
35 
0-8 
15-2 
16-8 
31-2 
0 
53 
0 
59 
1 
4 
1 
10 
1 
16 
1 
21 
1 
27 
1 
32 
1 
37 
1 
43 
1 
48 
0*9 
15-1 
16-9 
3M 
1 
0 
1 
6 
1 
12 
1 
19 
1 
25 
1 
31 
1 
37 
] 
43 
1 
49 
1 
55 
2 
1 
1-0 
15-0 
17-0 
31-0 
1 
7 
1 
14 
1 
20 
1 
27 
1 
34 
1 
41 
1 
48 
1 
55 
2 
1 
2 
8 
2 
14 
M 
14-9 
17-1 
30-9 
1 
14 
1 
21 
1 
28 
1 
36 
1 
43 
1 
51 
1 
59 
2 
6 
2 
13 
2 
21 
2 
28 
1-2 
14-8 
17-2 
30-8 
1 
20 
1 
28 
1 
36 
1 
45 
1 
53 
2 
1 
2 
10 
2 
18 
2 
26 
2 
34 
2 
41 
1-3 
14-7 
17-3 
30-7 
1 
27 
1 
36 
1 
44 
1 
53 
2 
2 
2 
11 
2 
20 
2 
29 
2 
38 
2 
46 
2 
54 
1-4 
14-6 
17-4 
30-6 
1 
33 
1 
43 
1 
52 
2 
2 
2 
11 
2 
20 
2 
30 
2 
40 
2 
49 
2 
58 
3 
7 
1-5 
14-5 
17*5 
30-5 
1 
40 
1 
50 
2 
0 
2 
10 
2 
20 
2 
30 
2 
41 
2 
51 
3 
1 
3 
11 
3 
20 
1-6 
14-4 
17-6 
30-4 
1 
46 
1 
57 
2 
8 
2 
19 
2 
29 
2 
40 
2 
51 
3 
2 
3 
12 
3 
23 
3 
33 
1*7 
14-3 
17-7 
30-3 
1 
53 
2 
5 
2 
16 
2 
28 
2 
39 
2 
50 
3 
1 
3 
12 
3 
23 
3 
35 
3 
46 
1-8 
14-2 
17-8 
30*2 
1 
59 
2 
11 
2 
23 
2 
36 
2 
48 
2 
59 
3 
11 
3 
23 
3 
34 
3 
46 
3 
58 
1-9 
14-1 
17-9 
30-1 
2 
6 
2 
19 
2 
31 
2 
44 
2 
56 
3 
9 
3 
21 
3 
33 
3 
45 
3 
58 
4 
10 
2-0 
14-0 
18-0 
30-0 
2 
12 
o 
25 
2 
38 
2 
51 
3 
4 
3 
18 
3 
31 
3 
44 
3 
57 
4 
10 
4 
23 
2-1 
13-9 
18*1 
29-9 
2 
18 
2 
32 
2 
46 
3 
0 
3 
13 
3 
27 
3 
41 
3 
55 
4 
8 
4 
22 
4 
35 
2-2 
13*8 
18-2 
29-8 
2 
24 
2 
39 
2 
53 
3 
8 
3 
22 
3 
36 
3 
50 
4 
5 
4 
19 
4 
34 
4 
48 
2-3 
13-7 
18-3 
29-7 
2 
30 
2 
45 
3 
0 
3 
15 
3 
30 
3 
45 
4 
0 
4 
15 
4 
30 
4 
45 
5 
0 
2‘4 
13-6 
18-4 
29-6 
2 
36 
2 
52 
3 
7 
3 
23 
3 
38 
3 
54 
4 
10 
4 
26 
4 
41 
4 
57 
5 
12 
2-5 
13-5 
18-5 
29-5 
2 
42 
2 
59 
3 
15 
3 
31 
3 
47 
4 
4 
4 
20 
4 
36 
4 
52 
5 
8 
5 
24 
2-6 
13-4 
18-6 
29*4 
2 
48 
3 
5 
3 
22 
3 
39 
3 
55 
4 
12 
4 
29 
4 
46 
5 
3 
5 
20 
5 
36 
2-7 
13-3 
18*7 
29-3 
2 
54 
3 
12 
3 
29 
3 
47 
4 
4 
4 
22 
4 
39 
4 
56 
5 
13 
5 
31 
5 
48 
2*8 
13-2 
18-8 
29*2 
3 
0 
3 
18 
3 
36 
3 
54 
4 
12 
4 
30 
4 
48 
5 
6 
5 
24 
5 
42 
6 
0 
2-9 
13*1 
18-9 
29-1 
3 
6 
3 
24 
3 
42 
4 
1 
4 
19 
4 
38 
4 
57 
5 
16 
5 
34 
5 
53 
6 
12 
.3-0 
13-0 
19-0 
29*0 
3 
11 
3 
30 
3 
49 
4 
9 
4 
27 
4 
47 
5 
6 
5 
25 
5 
44 
6 
4 
6 
23 
3-1 
12-9 
19-1 
28-9 
3 
17 
3 
37 
3 
56 
4 
16 
4 
35 
4 
55 
5 
15 
5 
35 
5 
54 
6 
14 
6 
34 
3-2 
12-8 
19-2 
28-8 
3 
22 
3 
44 
4 
3 
4 
23 
4 
43 
5 
4 
5 
24 
5 
44 
6 
4 
6 
25 
6 
45 
3-3 
12-7 
19-3 
28-7 
3 
28 
3 
50 
4 
9 
4 
30 
4 
51^ 
5 
12 
5 
33 
5 
54 
6 
14 
6 
35 
6 
56 
3-4 
12-6 
19-4 
28-6 
3 
33 
3 
55 
4 
16 
4 
38 
4 
59 
5 
21 
5 
42 
6 
3 
6 
24 
6 
46 
7 
7 
3-5 
12-5 
19-5 
28-5 
3 
39 
4 
1 
4 
23 
4 
45 
5 
7 
5 
29 
5 
51 
6 
13 
6 
34 
6 
56 
7 
18 
.3-6 
12-4 
19-6 
28*4 
3 
44 
4 
7 
4 
29 
4 
52 
5 
14 
5 
37 
5 
59 
6 
21 
6 
43 
7 
6 
7 
28 
3-7 
12-3 
19-7 
28-3 
3 
49 
4 
12 
4 
35 
4 
58 
5 
21 
5 
44 
6 
7 
6 
30 
6 
52 
7 
15 
7 38 
3-8 
12-2 
19-8 
28-2 
3 
54 
4 
18 
4 
41 
5 
5 
5 
28 
5 
52 
6 
15 
6 
38 
7 
1 
7 
25 
7 48 
3-9 
12-1 
19-9 
28-1 
3 
59 
4 
23 
4 
47 
5 
11 
5 
35 
5 
59 
6 
23 
6 
47 
7 
10 
7 
34 
7 58 
4-0 
12-0 
200 
28-0 
4 
4 
4 
28 
4 
53 
5 
17 
5 
42 
6 
6 
6 
30 
6 
55 
7 
19 
7 
44 
8 
8 
+ 
