206 W. A. Norton on the Variations of the Declination 
four hours of noon, because it is then that its position changes 
most rapidly, (p. 209). At the same hours the primary current is 
in its position of minimum action. ‘Table I. gives for the de- 
flection in September between 8 a.m. and 12 m. 9°78, and be-' 
tween 12m. and 4 Pp. m. 485. 
At other periods of the year the general character of the effects 
of the currents may be readily ascertained if we reflect that in 
the summer months, the currents of the Northern Hemisphere pre- 
vail throughout the day, while in the winter months the currents 
of the Southern Hemisphere come into prevailing action in the 
morning hours, from 4or 5 a. m. to 8 or 9 a.m.; and that toward 
the equinoxes the effect of the primary ecliptic current is greater 
than at other seasons. We see therefore that the curves for the 
summer months should resemble that for the day of the sum- 
mer solstice, and the curves for the winter months that for the 
day of the winter solstice; and that the curves for March and 
September should be somewhat different. (See Fig. 6, also 
Hobarton Observations, Vol. I, p. 34.) The change froma west- 
ward to an eastward tendency at the hour of 6 a. m. in the win- 
ter months, is observable in the curves 5, 6, 7, 8, of Fig. 6. Pre- 
vious to 5 a. m. there is a slight eastward tendency, except in the 
curve for January. This I ascribe to the easterly deflection that 
follows the meridian passage of the point of maximum electric 
excitement diametrically opposite the sun. This point should be 
particularly effective in the winter, because its declination is north. 
‘The opposite change of tendency, viz., from east to west, at 6 4.M. 
is to be seen in the curves 1, 2,3, 4. That the. westerly motion 
does not actually begin at that hour I suppose to be owing to the 
action of th® radial currents, which tend to urge the needle to- 
ward the east early in the forenoon. The greater part of the 
movement in this direction previous to 6 A. m., is doubtless attrib- 
utable to the same action of the radial currents. 
If we compare any one curve with the others, we find that 
the differences and correspondences which subsist, are in almost 
every instance such as the theory calls for. Thus, at 6 a.m. the 
the station (Toronto) in August as in June, and it 
is possible that this may over-balance the diminution of the 
obliquity of the currents. . Again, from the predominance of ‘the: 
currents of the Southern Hemisphere, there should be an espe- 
ial tendency to a westward displacement of the needle, at the 
