OF THE MAGNETIC DECLINATION AT POINT BAEEOW. 
509 
disturbance-variation at Toronto, and of the westerly disturbance-variation at Point 
Barrow at those hours remains (as is undoubtedly the case) in the body of the observations 
after the separation of the larger disturbances. The prevailing disturbances are easterly 
at Toronto and westerly at Point Barrow from 6 to 7 p.m. until 3 to 4 a.m. ; and the 
influence of that portion of them which is not separated must necessarily have the effect 
of augmenting the rapidity of the easterly motion at Toronto, and of retarding it at 
Point BaiTow. 
Table V. 
Dimmal Variation of the Dechnation at Point Barrow, derived from the mean of seven- 
teen months of homly observation. Column A shows the results when the large 
distm’bances are retained ; Column B the results when the large disturbances are 
omitted ; and Column C the diflierences, or the diurnal variation due to the large 
disturbances. Column D shows (for the purpose of comparison with B) the diur- 
nal variation at Toronto omitting the large disturbances. 
Local 
astronomical 
hours. 
Point Barrow. 
Retaining 
the large 
disturbances. 
Point Barrow. 
Omitting 
the large 
disturbances. 
Point Barrow. 
Diurnal variation 
due to the large 
disturbances. 
Toronto. 
Omitting 
the large 
disturbances. 
Local civil hours. 
A. 
B. 
c. 
D. 
18 
19-3 E. 
14*6 E. 
i-1 E. 
3-0 E. 
6 A.M. 
19 
27-1 E. 
15-2 E. 
11-9 E. 
4-0 E. 
7 A.m. 
20 
27-0 E. 
12-7 E. 
14-3 E. 
4*4 E. 
8 A.m. 
21 
19-9 E. 
8-2 E. 
11*7 E. 
3-6 E. 
9 a.m. 
22 
9*3 E. 
3-8 E. 
5-5 E. 
1-2 E. 
10 A.M. 
23 
0-4 W. 
1-4 W. 
1-0 E. 
1-7 W. 
1 1 A.M. 
0 
8-2 VV. 
4-8 VV. 
3-4 W. 
4-0 W. 
Noon. 
1 
10-7 w. 
8-2 VV. 
2-5 VV. 
5-1 W. 
1 P.M. 
2 
9-8 W. 
7*5 VV. 
2-3 VV. 
4-9 WL 
2 P.M. 
3 
9-9 W. 
7-2 VV. 
2-7 WL 
3-8 W. 
3 P.M. 
4 
9-8 W. 
7-2 VV. 
2-6 VV. 
2*5 W. 
4 P.M. 
5 
10-2 W. 
7-0 VV. 
3-2 WL 
1*3 W. 
5 P.M. 
6 
9-7 W. 
6-7 VV. 
3-0 W. 
0-5 W. 
6 P.M. 
7 
8-4 W. 
4-4 VV. 
4-0 W. 
0-1 VV. 
7 P.M. 
8 
9*0 W. 
3-8 VV. 
5-2 W. 
0-2 E. 
8 P.M. 
9 
7-5 W. 
3*9 VV. 
3-6 W. 
0-5 E. 
9 P.M. 
10 
7-9 W. 
4-4 VV. 
3-5 W. 
0-7 E. 
10 P.M. 
11 
11-5 W. 
5-2 VV. 
6-3 W. 
0-7 E. 
11 P.M. 
12 
10-8 W. 
5-3 W. 
5-5 W. 
0-6 E. 
Midnight. 
13 
8-0 W. 
2-8 VV. 
5-2 W. 
0*5 E. 
1 A.M. 
14 
1-9 W. 
0-6 E. 
2-5 VV. 
0*5 E. 
2 A.M. 
15 
3-6 E. 
4-4 E. 
0-8 VV. 
0-7 E. 
3 A.M. 
16 
10-9 E. 
9-0 E. 
1-9 E. 
M E. 
4 A.M. 
17 
16-6 E. 
11-4 E. 
5-2 E. 
1-9 E. 
5 A.M. 
It must be regarded as a strong confirmation of the propriety of considering the 
regular solar-diurnal variation and the disturbance-variation as distinct classes of pheno- 
mena, requiring their respective laws to be separately investigated, when we see the 
correspondence between the principal features of the one variation (the regular solar- 
dimmal), and the antagonism of those of the other (the disturbance-variation), exempli- 
fied as they are at Point Barrow and Toronto ; the epochs of extreme easterly and of 
