16 
MR. E. CHAMBERS ON THE DIURNAL VARIATIONS 
Table VII. — Mean North or South and East or West components of the Wind at 
Toronto for each hour of the day, during the years 1854 to 1859 inclusive, also 
their mean diurnal variations for the same period. 
Toronto Civil Hours 
0 to 1. 
1-2. 
2-3. 
3-4. 
4-5. 
5-6. 
6-7. 
7-8. 
N. or S. component 
T65 n. 
T78 n. 
1-78 n. 
1-75 n. 
1-67 n. 
1-66 n. 
1-71 N. 
1-65 n. 
Variation 
0 64 n. 
077 n. 
077 n. 
0-74 n. 
0-66 n. 
0 65 n. 
0-70 n. 
0 64 n. 
E. or W. component 
1-53 w. 
1-49 w. 
1-50 w. 
1-42 w. 
1-35 w. 
1-30 w. 
1-43 w. 
149 w. 
Variation 
0-40 e. 
0-44 e. 
0-43 e. 
0-51 e. 
0-58 e. 
0-63 e. 
0-50 e. 
0 44 e. 
Toronto Civil Hours 
8-9. 
9-10. 
10-11. 
11-12. 
12-13. 
13-14. 
14-15. 
15-16. 
N. or S. component 
1-49 n. 
102 n. 
0-38 n. 
0 25 s. 
0-59 s. 
0-61 s. 
0-52 s. 
0-00 
Variation 
0-48 n. 
001 N. 
0-63 s. 
1-26 s. 
1-60 s. 
1-62 s. 
1-53 s. 
L 07 s. 
E. or W. component 
T65 w. 
2 00 w. 
2-15 w. 
2-36 w. 
254 w. 
2-64 w. 
2 65 w. 
2-56 w. 
Variation 
0-28 e. 
0 07 w. 
0-22 w. 
0-43 w. 
0-61 w. 
0 71 w. 
0 72 w. 
0-63 w. 
Toronto Civil Hours 
16-17. 
17-18. 
18-19. 
19-20. 
20-21. 
21-22. 
22-23. 
23-0. 
N. or S. component 
0-58 n. 
085 n. 
107 n. 
1-23 n. 
1-31 N. 
1-50 n. 
T58 n. 
T58 n. 
Variation 
0-43 s. 
0-16 s. 
0 06 n. 
0-22 n. 
0-30 n. 
0-49 n. 
0-57 x. 
0-57 n. 
E. or W. component 
2-53 \v. 
2-33 w. 
2-17 w. 
2 04 w. 
T95 w. 
1-85 w. 
1-75 w. 
1 -64 w. 
Variation 
0 60 w. 
0 40 w. 
0 24 w. 
O il w. 
0 02 w. 
0 08 e. 
018 e. 
0-29 e. 
The mean components for the whole period are T01 N. and 1*93 W. 
19. Now, confining our attention to the northern hemisphere, and supposing the sun 
to have no declination, a little consideration will show that a double diurnal variation 
of the wind like that represented by fig. 9 cannot subsist in all latitudes, for such a 
supposition would lead to a contradiction when the pole was reached ; for it would require 
that winds should be found there blowing in opposite directions at the same time, which 
is of course absurd. The two influences, however, which produce the two north and 
south oscillations in low latitudes may be supposed to exist at the same time even at 
the pole, tending to produce motion in opposite directions : the movement produced will 
therefore be due to the difference of these influences ; and as the greater influence is that 
which produces the larger oscillation in low latitudes, the result will be a transference 
of air across the pole from the hot to the cold hemisphere, or, which is the same thing, 
a motion of the air from the sun. It follows that the diurnal variation at the pole will 
consist of a single rotation, the diurnal-variation curve being a circle — or, in other words, 
a vane placed there and influenced only by this variation will “ veer ” round at the uniform 
rate of 15° per hour. If we suppose such a variation to exist at the pole, then in middle 
latitudes we should expect to find the diurnal variation of the wind partaking of the 
characteristics both of the variation at the pole and that in low latitudes ; and such 
