ctions of the parent mass, and so produce
planets and their satellites--an inference strongly supported by the
still extant rings of Saturn.

Should it hereafter be satisfactorily shown that planets and satellites
were thus generated, a striking illustration will be afforded of the
highly heterogeneous effects produced by the primary homogeneous cause;
but it will serve our present purpose to point to the fact that from the
mutual attraction of the particles of an irregular nebulous mass there
result condensation, rotation, heat, and light.

It follows as a corollary from the Nebular Hypothesis, that the Earth
must at first have been incandescent; and whether the Nebular Hypothesis
be true or not, this original incandescence of the Earth is now
inductively established--or, if not established, at least rendered so
highly probable that it is a generally admitted geological doctrine. Let
us look first at the astronomical attributes of this once molten globe.
From its rotation there result the oblateness of its form, the
alternations of day and night, and (under the influence of the moon) the
tides, aqueous and atmospheric. From the inclination of its axis, there
result the precession of the equinoxes and the many differences of the
seasons, both simultaneous and successive, that pervade its surface.
Thus the multiplication of effects is obvious. Several of the
differentiations due to the gradual cooling of the Earth have been
already noticed--as the formation of a crust, the solidification of
sublimed elements, the precipitation of water, etc.,--and we here again
refer to them merely to point out that they are simultaneous effects of
the one cause, diminishing heat.

Let us now, however, observe the multiplied changes afterwards arising
from the continuance of this one cause. The cooling of the Earth
involves its contraction. Hence the solid crust first formed is
presently too large for the shrinking nucleus; and as it cannot support
itself, inevitably follows the nucleus. But a spheroidal envelope cannot
sink down into contact with a smaller internal spheroid, without
disruption; it must run into wrinkles as the rind of an apple does when
the bulk of its interior decreases from evaporation. As the cooling
progresses and the envelope thickens, the ridges consequent on these
contractions must become greater, rising ultimately into hills and
mountains; and the later systems of mountains thus produced must not
only be high