IN THE MEAN EFFECTS OF THE LARGER MAGNETIC DISTURBANCES. 107 
We now pass to the westerly disturbances at Toronto and easterly at Hobarton, — 
and in Table IV. the ratios of the numbers and aggreg'ate values are arranged oppo- 
site to the respective hours; the mean hourly number and aggregate value being 
taken as the respective units. 
Table IV. 
Hours of local 
astronomical 
time. 
Toronto. 
Hobarton. 
Hours of local 
astronomical 
time. 
Numbers. 
Values. 
Numbers. 
Values. 
h 
h 
18 
1-17 
1-33 
0-94 
1-02 
18 
19 
1-27 
2-16 
1-33 
1-33 
19 
20 
1-46 
1*87 
1-41 
1-38 
20 
21 
1-39 
1*69 
1-41 
1-41 
21 
22 
1*40 
1*33 
1-30 
1-27 
22 
23 
1-27 
1-04 
1-32 
1-24 
23 
0 
1-10 
0-89 
1-23 
M4 
0 
1 
0-89 
0-66 
1-38 
1*26 
1 
2 
0-75 
0-64 
1-38 
1-32 
2 
3 
0-99 
0-74 
1*33 
1-40 
3 
4 
0-96 
0-76 
1-30 
1*39 
4 
5 
0-91 
0-74 
M6 
1-32 
5 
6 
0-75 
0-63 
1-01 
M6 
6 
7 
0-63 
0-51 
0-64 
0-62 
7 
8 
0-61 
0-46 
0-43 
0-40 
8 
9 
0-60 
0-48 
0-29 
0-32 
9 
10 
0-48 
0-34 
0-36 
0-28 
10 
11 
0-66 
0-32 
0-88 
0-74 
11 
12 
0-73 
0-81 
0-74 
0-62 
12 
13 
0-99 
MO 
0-64 
0*33 
13 
14 
1-21 
1-08 
0-70 
0-63 
14 
15 
1*23 
1*06 
0-86 
0-83 
13 
16 
1-38 
1-23 
1-09 
1-07 
16 
17 
1*19 
1*31 
0-67 
0-87 
17 
On examining this Table, we perceive that in this division of the larger disturb- 
ances at Toronto and Hobarton, viz. those which are westerly at Toronto and 
easterly at Hobarton, there is also a very marked and systematic variation dependent 
upon the hours of local time, but the correspondence of the variation at similar 
hours of local time at the two stations is not so complete as in the former case. At 
Hobarton, the contrast both in frequency and aggregate value is still between the 
hours of the day and those of the night; at Toronto it is between the hours from 
noon to midnight, and those from midnight to noon. At Hobarton, the nodal hours, 
if they may be so called, are, both in the westerly and easterly disturbances, about 
6 A.M. and 6 p.m. ; at Toronto they are in the easterly disturbances, about 6 a.m. and 
6 P.M. ; but in the westerly, six hours different, or about noon and midnight. At 
Hobarton, in the westerly disturbances the ratios are greater than unity in the night 
hours, or from 6 p.m. to 6 a.m., and less than unity in the day hours, or from 6 a.m. to 
6 P.M. ; whilst in the easterly disturbance the converse takes place, the ratios being 
greater than unity in the day hours, and less than unity in the night hours. At 
p 2 
