eminently the case with the nebulous hypothesis, for here the
associated facts cannot be explained on any other supposition. We
have seen reason to conclude that the primary condition of matter was
that of a diffused mass, in which the component molecules were
probably kept apart through the efficacy of heat; that portions of
this agglomerated into suns, which threw off planets; that these
planets were at first very much diffused, but gradually contracted by
cooling to their present dimensions. Now, as to our own globe, there
is a remarkable proof of its having been in a fluid state at the time
when it was finally solidifying, in the fact of its being bulged at
the equator, the very form which a soft revolving body takes, and
must inevitably take, under the influence of centrifugal force. This
bulging makes the equatorial exceed the polar diameter as 230 to 229,
which has been demonstrated to be precisely the departure from a
correct sphere which might be predicated from a knowledge of the
amount of the mass and the rate of rotation. There is an almost
equally distinct memorial of the original high temperature of the
materials, in the store of heat which still exists in the interior.
The immediate surface of the earth, be it observed, exhibits only the
temperature which might be expected to be imparted to such materials,
by the heat of the sun. There is a point, very short way down, but
varying in different climes, where all effect from the sun's rays
ceases. Then, however, commences a temperature from an entirely
different cause, one which evidently has its source in the interior
of the earth, and which regularly increases as we descend to greater
and greater depths, the rate of increment being about one degree
Fahrenheit for every sixty feet; and of this high temperature there
are other evidences, in the phenomena of volcanoes and thermal
springs, as well as in what is ascertained with regard to the density
of the entire mass of the earth. This, it will be remembered, is