136 
LIEUT.-COLONEL SABINE ON PERIODICAL LAWS DISCOVERABLE 
hours of the morning to 6 and 7 p-m., the average number of westerly disturbed ob- 
servations is considerably less than half the average number during the hours of the 
night (8 p.M. to 3 a.m. inclusive) ; whilst the contrast is still greater (as in the case of 
the easterly disturbed observations at Toronto) between the hours of the afternoon 
(2 to 6 p.m.) and the early hours of the night (8 p.m. to 1 a.m.). 
The hours of the maximum occurrence of the westerly disturbances are also those 
of the minimum occurrence of easterly disturbances, and the latter do not appear to 
have any marked epoch of maximum occurrence at other hours. 
Referring back to the comments on Tables III., IV., V. and VI., the analogy 
between the two stations will be seen to be most striking. Laws derived directly 
from the phenomena, and having so much in common at stations so widely remote 
from each other, cannot be regarded as accidental, and claim to be viewed as a step 
gained in the analytical examination of the magnetic phenomena and in their classifi- 
cation ; in the path therefore which, according to the principles of the inductive 
philosophy, conducts from a knowledge of effects to the perception of their cause or 
causes. We have traced in the largest and most influential portion of the disturb- 
ances, belonging to the class which has hitherto borne the name of “irregular,” the 
existence of a law connecting them with the local hours of the station at which they 
were observed ; and in the accordance of this law, as severally deduced at Toronto 
and Hobarton, we see reason to attribute to it a more general character than that of 
a mere dependence on the peculiarities of particular stations. In order that this may 
be more clearly seen, I have placed in the next Table a comparative view of the 
diurnal variation derived from the larger disturbances at Toronto and Hobarton, on 
the average of the three years under discussion. The phenomena at Toronto are 
reproduced from Table VII., and those at Hobarton have been obtained in the same 
manner as at Toronto, and as is described in the paragraph which immediately pre- 
cedes Table VII. 
Table XI. 
Local time. 
Hobarton. 
Toronto. I 
1 
Local time. 
Hobarton. 
Toronto. 
6 A.M 
0’03 East. 
0'02 West. 
6 P.M 
0*04 West. 
0*l6 East. 
7 A.M 
0‘06 East. 
0*02 West. 
7 P.M 
0*1 6 West. 
0*28 East. 
8 A.M 
O' 02 East. 
0*10 West. 
8 P.M 
0*27 West. 
0*56 East. 
9 A.M 
0*04 East. 
0*09 West. 
9 P-M 
0*39 West. 
0*79 East. 
10 A.M 
0'03 East. 
0*06 West. 
10 P.M 
0*42 West. 
0*75 East. 
11 A.M 
0'03 East. 
0*01 East. 
11 P.M 
0*41 West. 
0*42 East. 
Noon 
0'02 East. 
0'09 West. 
Midnight ... 
0*38 West. 
0*36 East. 
1 P.M 
0'04 East. 
0*02 West. 
1 A.M 
0*34 West. 
0*33 East. 
2 P.M 
0'05 East. 
0*04 West. 
2 A.M 
0*24 West. 
0*20 East. 
3 P.M 
0'06 East. 
0*08 West. 
3 A.M 
0*12 West. 
0*14 East. 
4 P.M 
0'05 East. 
0'03 West. 
4 A.M 
0*02 West. 
0*03 East. 
5 P.M 
O'Ol East. 
0*05 East. 
5 A.M 
0*03 East. 
0*00 
The general character at the two stations (easterly deflections at the one being 
equivalent, as already stated, to westerly at the other) is strikingly accordant : the 
principal difference appears to consist in the mean easterly deflection at Toronto 
