quondam planet, and their mean distances must consequently vary also.

There are some other peculiarities connecting the distances and
densities, to which we shall devote a few words. In the primordial state
of the system, when the nebulous masses agglomerated into spheres, the
diameter of these nebulous spheres would be determined by the relation
existing between the rotation of the mass, and the gravitating force at
the centre; for as long as the centrifugal force at the equator exceeded
the gravitating force, there would be a continual throwing off of matter
from the equator, as fast as it was brought from the poles, until a
balance was produced. It is also extremely probable, (especially if the
elementary components of water are as abundant in other planets as we
have reason to suppose them to be on the earth,) that the condensation
of the gaseous planets into liquids and solids, was effected in a _brief
period of time_,[38] leaving the lighter and more elastic substances as
a nebulous atmosphere around globes of semi-fluid matter, whose
diameters have never been much increased by the subsequent condensation
of their gaseous envelopes. The extent of these atmospheres being (in
the way pointed out) determined by the rotation, their subsequent
condensation has not therefore changed the original rotation of the
central globe by any appreciable quantity. The present rotation of the
planets, is therefore competent to determine the former diameters of the
nebulous planets, _i.e._, the limit where the present central force
would be balanced by the centrifugal force of rotation. If we make the
calculation for the planets, and take for the unit of each planet its
present diameter, we shall find that they have condensed from their
original nebulous state, by a quantity dependent on the distance, from
the centre of the system; and therefore on the original temperature of
the nebulous mass at that particular distance. Let us make the
calculation for Jupiter and the earth, and call the original nebulous
planets the nucleus of the vortex. We find the Equatorial diameter of
Jupiter's nucleus in equatorial diameters of Jupiter = 2.21, and the
equatorial diameter of the earth's nucleus, in equatorial diameters of
the earth = 6.59. Now, if we take the original temperature of the
nebulous planets to be inversely, as the squares of the distances from
the sun, and their volumes directly as the cubes of the diameters in the
unit of each,