at we understand of
visible, palpable, or otherwise appreciable nebulosity.

Now, the condition of this mass implies a rotation about an imaginary
axis--a rotation which, commencing with the absolute incipiency of the
aggregation, has been ever since acquiring velocity. The very first two
atoms which met, approaching each other from points not diametrically
opposite, would, in rushing partially past each other, form a nucleus
for the rotary movement described. How this would increase in velocity,
is readily seen. The two atoms are joined by others:--an aggregation is
formed. The mass continues to rotate while condensing. But any atom at
the circumference has, of course, a more rapid motion than one nearer
the centre. The outer atom, however, with its superior velocity,
approaches the centre; carrying this superior velocity with it as it
goes. Thus every atom, proceeding inwardly, and finally attaching itself
to the condensed centre, adds something to the original velocity of that
centre--that is to say, increases the rotary movement of the mass.

Let us now suppose this mass so far condensed that it occupies
_precisely_ the space circumscribed by the orbit of Neptune, and that
the velocity with which the surface of the mass moves, in the general
rotation, is precisely that velocity with which Neptune now revolves
about the Sun. At this epoch, then, we are to understand that the
constantly increasing centrifugal force, having gotten the better of the
non-increasing centripetal, loosened and separated the exterior and
least condensed stratum, or a few of the exterior and least condensed
strata, at the equator of the sphere, where the tangential velocity
predominated; so that these strata formed about the main body an
independent ring encircling the equatorial regions:--just as the exterior
portion thrown off, by excessive velocity of rotation, from a
grindstone, would form a ring about the grindstone, but for the solidity
of the superficial material: were this caoutchouc, or anything similar
in consistency, precisely the phaenomenon I describe would be presented.

The ring thus whirled from the nebulous mass, _revolved_, of course,
_as_ a separate ring, with just that velocity with which, while the
surface of the mass, it _rotated_. In the meantime, condensation still
proceeding, the interval between the discharged ring and the main body
continued to increase, until the former was left at a vast distance from
the latter