W. A. Norton on Molecular Physics. 67 
earth, or two corresponding sets of currents traversing the earth’s 
crust. These currents were called, respectively, radial, and eclip- 
tic ; the radial currents radiating from the region of the photo- 
sphere most directly exposed to the impulsive action of the sun’s 
rays, and the ecliptic originating on the side of the earth toward 
the sun, and in directions parallel to the plane of the ecliptic. 
We have now to observe, (1.) That the ecliptic currents running 
from east to west, formerly supposed to be developed in the 
earth’s photosphere, have their counterparts in currents runnin 
from west to east in the crust of the earth, and developed by 
of the earth, are conspicuously observable in the variations of 
the declination and horizontal force during the last half of the 
night and the earlier part of the day. As the day advances, the 
are 
_ force in the afternoon. The change of the hours of the: morn- 
ing maxima and minima with the seasons, 1s mainly a conse- 
quence of the changes experienced during the year, in the posi- 
tion of the circle of the earth, perpendicular to the radius of the 
earth’s orbit at 6 A. ., with respect to a meridian passing through 
€quinoxes; is inclin ed 234° to it, on the west side, at the scanned me 
_ * The special effects here alluded to, and in general the effects referred to in what = 
