120 
COLONEL SABINE ON PERIODICAL LAWS DISCOVERABLE 
Table XIX. — Mean monthly diurnal range of the Total Force at Toronto, in parts 
of the Force. 
Years. 
Winter. 
Spring and Autumn. 
Summer. j 
Mean in the 
whole year. 
November, December, 
January, February. 
March, April, 
September, Oetober. 
May, June, j 
July, August. j 
1843 
•00028 
•00040 
•00040 
•00036 
1844 
•00027 
•00059 
•00039 
•00042 
1845 
•00032 
•00038 
•00046 
•00039 
1846 
•00020 
•00059 
•00077 
•00052 
1847 
•00048 
•00064 
•00052 
•00055 
1848 
•00061 
•00075 
•00054 
•00063 
Table XX. — Mean monthly diurnal range of the Inclination at Hobarton. 
Years. 
Winter. 
Spring and Autumn. 
Summer. 
Mean in the 
whole year. 
May, June, 
July, August. 
September, October, 
March, April. 
November, December, 
January, February. 
1843 
i-43 
1-68 
i-58 
1-56 
1844 
1-39 
1-76 
1-72 
1-62 
1845 
1-25 
1-78 
2-42 
1-85 
1846 
1-62 
2-04 
2-36 
2-01 
1847 
1-54 
2-45 
2-70 
2-23 
1848 
1-92 
2-40 
3-27 
2-53 
Table XXI.—Mean monthly diurnal range of the Total Force at Hobarton, in 
parts of the Force. 
Y ears. 
Winter. 
Spring and Autumn. 
Summer. 
Mean in the 
whole year. 
May, June, 
July, August. 
September, October, 
March, April. 
November, December, 
January, February. 
1843 
•00057 
•00043 
•00049 
•00050 
1844 
•00029 
•00033 
•00038 
•00033 
1845 
•00031 
•00031 
•00036 
•00033 
1846 
•00033 
•00038 
•00039 
•00037 
1847 
•00031 
•00040 
•00049 
•00040 
1848......... 
•00032 
•00039 
■00063 
•00045 
We perceive by these Tables that the indications of a periodical inequality are not 
less general in magnetical respects, i. e. in their extension to all the magnetical 
elements, than in their manifestation in parts of the globe most remote from each 
other. In the Inclination, the progressive increase is as distinctly marked as in the 
Declination ; and if it is somewhat less so in the Total Force, this may with some 
probability be ascribed to the less perfect instrumental means from which the diurnal 
variation of that element is chiefly derived. In our present ignorance of the physical 
agency by which the periodical magnetic variations are produced, the possibility of 
the discovery of some cosmical connection which may throw light on a subject as 
