1th, 244
1846, " 10th, 128
1852, " 9th, 12
1858, " 8th, 255
1864, " 7th, 139
1870, " 6th, 23
1876, " 5th, 267

By this we see that the vortices have never attained their highest limit
during the present century, but that in 1858 their range will be in a
tolerable high latitude, and still higher in 1876--neglecting the
eccentricity of the orbit.

A very potent influence is also due to the heliocentric longitude of the
sun, in determining the character of any given year. Let us explain:

The moon's inertia forces the earth from the mechanical centre of the
terral system, but is never able to force her clear from the central
axis. With the sun it is different. He possesses many satellites
(planets). Jupiter alone, from his great mass and distance, is able to
displace the whole body of the sun. If other planets conspire at the
same side, the centre of the sun may be displaced a million of miles
from the mechanical centre of the solar system. Considering this centre,
therefore, as the centre of an imaginary sun, from which heliocentric
longitudes are reckoned, the longitude of the real sun will vary with
the positions of the great planets of the system. Now, although this
_systematic_ longitude will not be exactly similar to the heliocentric
longitude reckoned from the sun's centre, yet, for the purposes
intended, it will correspond sufficiently, and we shall speak of the
longitude of the sun as if we reckoned heliocentric longitudes from the
mechanical centre of the system. When we come to consider the solar
spots, we shall enter into this more fully. In the following diagram we
shall be able to perceive a cause for variation of seasons in a given
year, as well as for the general character of that year.

[Illustration: Fig. 21]

Let S represent the centre of the sun, and the circle a vertical section
of the sun, cutting; through the centre,--SJ being in the equatorial
plane of the vortex, of which ZZ' represents the axis. As the ether
descends the poles or axis at Z, it is met by the current down the
opposite pole, and is thence deflected in radii along the equatorial
plane to J. But on the side S, the ether is opposed by the body of the
sun; its direction is consequently changed, and cross currents are
produced, assuming it as a principle, that the ethereal fluid is
permeable by other currents of simi