s from 200 to
400 miles. To find the precise centre, by one observer confined to one
place, is difficult; and to separate them, so as to be fully assured
that you have the right one, is perhaps still more so. Happily this
tedious labor is accomplished, and we are able with confidence to give
the following important elements, as very close approximations to the
truth:

Mass of the moon 1/72.3
Obliquity of the axis of the vortex 15d to 32d variable.
Right ascension of ditto 250d to 290d variable.

It must be borne in mind that we are now discussing the main or central
vortex of the earth; but before applying them to the calculation, we
will explain the _modus operandi_, waiving for the present the
consideration of the law of density in the Terral vortex. It is evident
at first sight that if the periodic times of the parts of the vortex
contiguous to the moon, are equal to the moon's period approximately,
that the velocity of the ether is greater at the surface of the earth
than the velocity of that surface. Now, we have before argued that the
ether possesses inertia, it therefore would under such circumstances
exert some mechanical action. Consequently, the aerial envelope of our
globe, or its superior stratum, is impelled eastward by _convection_[4]
of the more rapidly rotating ether. And from the extreme tenuity of its
upper layers, is probably forced into immense waves, which will observe
to a certain degree, a general parallelism north and south.

ATMOSPHERIC CURRENTS.

It is a well-known fact, that the prevailing current of the atmosphere
in high latitudes is from the westward. The cause of this is ascribed by
Professor Dove to the transfer of the equatorial portions to a higher
latitude, by which the excess of its rotative velocity is made apparent,
by outstripping the slower moving surface in its progress eastward. No
doubt some effect is due to this, but still a difficulty remains. Let us
follow this current. The polar current reaches the surface on the
borders of the trades with less rotative velocity than the surface, and
is, therefore, met by the surface as a current partaking of both
motions. In the northern hemisphere it is north-east deflected to east
as it approaches the southern trades. By the same reasoning, coming from
the north before it readies the surface, it ought to be also a
north-east wind above the lower westerly currents. Now it is an observed
fa