Those elements which represent the moon's distance and motion are
accurately known, and may be taken from the Nautical Almanac, being all
embodied in the moon's parallax or semi-diameter, and in the declination
and right ascension; but for the most important element,--the moon's
mass, we in vain look to astronomy. In fact, it may be averred that the
importance attached to astronomical authority, concerning the mass of
the moon, has caused more trouble than any other question of the whole
theory, until we trusted implicitly to the theory itself to determine
it. The determination of three unknown elements, viz.: the moon's mass,
the inclination of the axis of the vortex, and the right ascension of
that axis, is a more difficult problem than at first sight appears,
owing to the nature of the phenomena, which affords the only clue for
its solution. There are six principal vortices ever in operation on the
surface of the earth, and their disturbing influence extends 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.