224 
THE ASTRONOMER ROYAL 
Table V. — Diurnal Magnetic Inequality in North Direction, inferred from Galvanic 
Earth-Currents. The unit is O'OOOOl of Total Horizontal Magnetic Force. 
Hours. 
1866 and 1867. 
January. 
1867. 
February. 
1867. 
March. 
1865 and 1867. 
April. 
1866 and 1867. 
May. 
1866 and 1867. 
June. 
1865 to 1867. 
July. 
1865 to 1867. 
August. 
1865 to 1867. 
September. 
1865 to 1867. 
October. 
1865 to 1867. 
.November. 
1865 to 1867. 
at 
-Q 
S 
o 
o 
a* 
Mean of the Inequality for the 
twenty-four hours. 
+ 44 
+ 59 
+ 67 
+ 46 
+ 40 
+ 38 
+ 43 
+ 52 
+ 51 
+ 43 
+ 38 
+ 38 
Simple Diurnal Inequality (to be 
multiplied by 0*526). 
0 
+ 
3 
+ 7 
+ 2 
+ 9 
+ 11 
~h 6 
+ 14 
+ 9 
+ 6 
+ 
4 
0 
+ 
l 
1 
+ 
1 
+ 10 
+ 6 
+ 12 
+ 14 
+ ii 
+ 17 
+ 14 
+ 9 
+ 
6 
0 
0 
2 
+ 
1 
+ 12 
+ 9 
+ 14 
+ 16 
+ 14 
+ 21 
+ 17 
+ 11 
+ 
8 
+ 
1 
— 
l 
3 
+ 
1 
+ 12 
+ 11 
+ 16 
+ 17 
+ 17 
+ 24 
+ 18 
+ 13 
+ 
9 
+ 
2 
— 
l 
4 
— 
2 
+ 12 
+ 12 
+ 18 
+ 18 
+ 18 
+ 24 
+ 20 
+ 13 
+ 10 
+ 
4 
— 
2 
5 
— 
2 
+ 12 
+ 13 
+ 17 
+ 18 
+ 18 
+ 22 
+ 19 
+ 13 
+ 10 
+ 
4 
— 
1 
6 
— 
2 
+ 10 
+ 13 
+ 15 
+ 15 
+ 17 
+ 19 
+ 17 
+ 13 
+ 
9 
+ 
3 
— 
4 
7 
— 
3 
+ 8 
+ 12 
+ 12 
+ 11 
+ 14 
+ 14 
+ 14 
+ 10 
+ 
7 
+ 
3 
— 
3 
8 
— 
4 
+ 5 
+ 11 
+ 9 
+ 8 
+ 11 
+ 9 
+ 10 
+ 7 
+ 
6 
+ 
3 
— 
3 
9 
— 
4 
+ 2 
+ 8 
+ 5 
+ 3 
+ 6 
+ 4 
+ 6 
+ 5 
+ 
5 
+ 
3 
— 
2 
10 
— 
3 
— 1 
+ 5 
0 
— 1 
+ 2 
- 3 
+ 1 
+ 1 
+ 
2 
+ 
1 
— 
2 
11 
— 
3 
— 5 
+ 1 
— 4 
— 5 
— 2 
- 9 
— 5 
- 3 
— 
2 
0 
— 
2 
12 
— 
3 
- 7 
- 2 
- 9 
-11 
- 6 
— 14 
- 9 
- 6 
— 
4 
0 
— 
1 
13 
— 
1 
- 10 
- 6 
— 12 
— 14 
-11 
-17 
— 14 
- 9 
— 
6 
0 
0 
14 
— 
1 
-12 
- 9 
— 14 
-16 
— 14 
-21 
-17 
— 11 
— 
8 
— 
1 
+ 
1 
15 
— 
1 
- 12 
-11 
-16 
-17 
-17 
24 
- 18 
- 13 
— 
9 
— 
2 
+ 
1 
16 
+ 
2 
-12 
-12 
-18 
-18 
-18 
— 24 
-20 
-13 
— 
10 
— 
4 
+ 
2 
17 
+ 
2 
-12 
-13 
-17 
— 18 
-18 
22 
-19 
-13 
— 
10 
— 
4 
+ 
1 
18 
+ 
2 
-10 
— 13 
-15 
— 15 
-17 
-19 
-17 
— 13 
— 
9 
— 
3 
+ 
4 
19 
+ 
3 
- 8 
-12 
— 12 
-11 
— 14 
-14 
-14 
-10 
— 
7 
— 
3 
+ 
3 
20 
+ 
4 
- 5 
-11 
- 9 
- 8 
— 11 
- 9 
— 10 
- 7 
— 
6 
— 
3 
+ 
3 
21 
+ 
4 
- 2 
— 8 
- 5 
- 3 
- 6 
- 4 
- 6 
- 5 
— 
5 
— 
3 
+ 
2 
22 
+ 
3 
+ 1 
— 5 
0 
+ 1 
- 2 
+ 3 
— 1 
- 1 
— 
0 
— 
1 
+ 
2 
23 
+ 
3 
+ 5 
— 1 
+ 4 
+ 5 
+ 2 
+ 9 
+ 5 
+ 3 
+ 
2 
0 
+ 
2 
Semidiurnal Inequality (to be n 
ul ti plied by 0 - 6l6). 
0 12 
— 
9 
- 7 
— 1 
+ 4 
+ 2 
0 
— 1 
+ 3 
+ 3 
0 
+ 
2 

3 
1 13 
— 
3 
+ 2 
+ 1 
+ 8 
+ 6 
+ 5 
+ 3 
+ 7 
+ 6 
+ 
1 
+ 
i 
+ 
1 
2 14 
+ 
4 
+ 9 
+ 4 
+ 9 
+ 7 
+ 8 
+ 6 
+ 9 
+ 7 
+ 
3 
+ 
6 
+ 
3 
3 15 
+ 
9 
+ 12 
+ 6 
+ 8 
+ 8 
+ 9 
+ 7 
+ 10 
+ 7 
+ 
5 
+ 
9 
+ 
5 
4 16 
+ 12 
+ 12 
+ 7 
+ 7 
+ 7 
+ 8 
+ 7 
+ 10 
+ 8 
+ 
6 
+ 
10 
+ 
6 
5 17 
+ 12 
+ 12 
+ 6 
+ 5 
+ 6 
+ 6 
+ 8 
+ 8 
+ 6 
+ 
5 
+ 
9 
+ 
6 
6 18 
+ 
9 
+ 9 
+ 2 
0 
+ 2 
+ 1 
+ 6 
+ 1 
+ 1 
+ 
2 
+ 
4 
+ 
4 
7 19 
+ 
3 
+ 2 
— 1 
- 6 
— 4 
2 
+ 1 
- 6 
- 6 
— 
3 
— 
4 
+ 
1 
8 20 
— 
4 
- 7 
- 6 
— 12 
— 11 
- 7 
- 6 
-12 
-12 
— 
6 
— 
9 
— 
3 
9 21 
— 
10 
-14 
- 9 
-13 
-13 
-10 
-10 
-13 
- 14 
— 
8 
— 
10 
— 
5 
10 22 
— 
14 
-16 
- 8 
- 9 
-10 
-10 
— 10 
— 9 
- 9 
— 
7 
— 
8 
— 
6 
11 23 
— 
15 
- 13 
— 4 
0 
- 4 
- 6 
- 6 
- 3 
— 3 
— 
4 
— 
5 
— 
4 
Tertio-diurnal Inequality (to be multiplied by 0 - 804). 
0 8 16 
+ 
2 
0 
+ 1 
+ 5 
+ 3 
+ 2 
+ 6 
+ 5 
+ 5 
+ 
4 
0 
0 
1 9 17 
+ 
4 
0 
+ 3 
+ 2 
+ 2 
+ 2 
+ 3 
+ 2 
+ 3 
+ 
3 
+ 
1 
+ 
1 
2 10 18 
+ 
3 
— 1 
4- 3 
— 1 
— 1 
0 
0 
— 1 
0 
+ 
1 
+ 
1 
0 
3 11 19 
0 
0 
+ 1 
- 4 
- 3 
__ 2 
- 6 
- 3 
— 4 
— 
0 
+ 
1 
0 
i 4 12 20 
— 
2 
0 
— 1 
- 5 
- 3 
o 
- 6 
— 5 
— 5 
— 
4 
0 
0 
5 13 21 
— 
4 
0 
- 3 
— 2 
o 
2 
*> 
*j 
2 
— 3 
— 
3 
— 
1 
— 
1 
6 14 22 
— 
3 
+ 1 
- 3 
+ 1 
+ 1 
0 
+ 2 
+ 1 
0 
— 
1 
— 
1 
0 
7 15 23 
0 
0 
— 1 
+ 4 
+ 3 
+ 2 
+ 6 
+ 3 
+ 4 
+ 
2 
— 
1 
0 
