101 
Table V. 
h. h. 
h. h. 
h. h. ! 
h. li. 
h. h. 
h. h. 
h. h. 
h. h. 
h. h. 
h. h. 
h, h. 
h. h. 
Means. 
0-2 
2-4 
4-6 
6-8 
8-10 
10-12 
12-14 
14-16 
16-18 
18-20 
20-22 
22-0 
1859 
2518 
24-52 
2193 
19-88 
18-83 
18-23 
18-23 
1819 
17-81 
1913 
21-68 
2619 
20-82 
1860 
25-53 
25-02 
23-04 
2118 
20 03 
19-32 
1856 
18-49 
18-31 
19-68 
22 ‘64 
26-24 
21-50 
1861 
23 76 
23 10 
21-18 
18-58 
1800 
17 39 
17-55 
1713 
17-51 
18-06 
20-02 
23-34 
19-63 
1862 
24-83 
23-88 
21-60 
1975 
18-93 
1871 
18-32 
18-21 
18-28 
19-48 
22-70 
24-79 
20-80 
1863 
25 01 
24-75 
22-63 
20-04 
18.99 
18-54 
19-06 
18-33 
18-45 
19-26 
2177 
25-02 
20 '99 
1864 
2319 
23-89 
21-58 
19-15 
18-03 
17-70 
17-21 
16-65 
16-39 
17-18 
20-32 
22-88 
19-54 
1865 
22-54 
21-99 
20-07 
1777 
1674 
16-31 
16 48 
16 ‘26 
16-39 
1716 
19-92 
22-12 
18-65 
Means. 
24-33 
23-88 
2172 
19-48 
18-50 
18-03 
17-91 
17-61 
17-59 
18-56 
21-29 
2436 
20-27 
Differences 0 
45 2 
•16 2-24 0-98 0 
•47 0 
•12 0 
•30 O' 
02 0 
■97 2 
73 3 
■07 0 
•03 
Table V. shows the actual mean annual bi-horary velo- 
cities of the wind for the seven years 1859-65; and it will 
be seen from the differences between the mean values at the 
foot of the table that the maximum velocity occurs at about 
Oh. 45m., the minimum at about 17h. 0m.; and that during 
the increase of velocity the rate of change was greatest at 
about 21h. 80m., and during the decrease at about 5h. 30m. 
Here we have the maximum occurring somewhat earlier 
than when the direction of the wind is taken into ac- 
count, thus bringing all the phases of the wind changes 
somewhat in advance, in point of time, of those of the 
magnetic variations, and indicating therefore that the 
magnetic disturbances are due to electrical currents gene- 
rated or modified by changes and disturbances of the 
atmosphere. 
Since writing the above I have been kindly favoured by 
Mr. Main, with a copy of the unpublished results of the 
Anemograph observations for 1866. These I have com- 
bined with the results of the previous seven years, and 
have obtained the following mean bi-horary values of the 
direction and movement of the wind, for the entire period 
of eight years : — 
h. 
0 ... 
Mean 
Direction. 
... 224 11 ... 
Mean 
Bi-horary 
Velocity. 
... 15-43 
h. 
12 ... 
Mean 
Direction. 
... 216 2 ... 
Mean 
Bi-horary 
Velocity. 
... 12-12 
2 ... 
... 225 19 ... 
... 15-73 
14 ... 
... 216 47 ... 
... 11-96 
4 ... 
... 223 10 ... 
... 14-89 
16 ... 
... 216 13 ... 
... 11-82 
6 ... 
... 220 20 ... 
... 13-32 
18 ... 
... 218 56 ... 
... 11-87 
8 ... 
... 216 36 ... 
... 12-41 
20 ... 
... 218 53 ... 
... 12 71 
10 ... 
... 214 42 ... 
... 12-24 
22 ... 
... 222 26 ... 
... 14-25 
