200 W. A. Norton on the Variations of the Declination 
the current developed within the Torrid Zone (or rather within 
a few degrees of the ecliptic) may be represented by a single cur; 
rent following the course of the ecliptic traced on the earth’s pho- 
tosphere. At the equinoxes the northerly currents will cross the 
meridian at noon, under larger angles than this single ecliptic cur- 
rent, but their tendency will be the same in the inequality just 
the entire system of currents now under consideration. At the 
solstices the currents will everywhere, at the outset be parallel to 
the equator, and the circle traced through the various points from 
which they proceed at any one instant, will be a meridian and 
correspond to the solstitial colure. The entire system of cur- 
rents will pass through the pole of this circle, lying on the equa- 
tor 90° to the west of the circle. As the earth rotates the circle 
of excitement with its pole will be carried toward the west, and 
the inclination of each of these currents to the meridian of any 
particular station will vary continually. The currents in question 
will also pass through the other pole, 90° to the east of the circle 
on which they originate, but they will flow from this pole toward 
the circle, and from the circle toward the other pole. To the west 
of the circle they are leading currents, to the east of it following 
currents. The two poles will i in all cases be diametrically oppo- 
site to each other, and on the ecliptic. The starting point of the 
current that passes through the zenith of the station also varies 
continually. At 6 a.m. and 6 p.m. this current issues at the pole, 
at noon its starting point is in ne zenith of the station. At the 
equinoces the circle of excitement will coincide with the circle of 
latitude (that is circle through the pole of the ecliptic) which 
passes through the equinoctial points. The currents will set out 
move along it toward the west.. At the vernal equinox the pole 
will follow the course of the A 28 Tropic. During the year it 
will move along the ecliptic from west to east, keeping always 
90° behind the sun. It will therefore pass pean yp from 
one deppic to the other, as the sun does, but be on one of the 
tude. At6 a.m. and 6p.m., on the day of the autumnal equi- 
nox, the current which traverses the zenith of the station origin- — 
ates at a point on its meridian 234° beyond the pole ; at noon at 
a point a few degrees to the south and east of the station, a 
crosses the meridian under an angle of 73°. At the same hours 
the day of the Sanat equinox, the current in question peas 
at the point on the meridian 233° ~ this side of the pole ; at noon 
a few degrees to the south and the mes ‘and deviates 
© from the meridian 
