Those who suppose that the earth contains within it the elements of its own destruction, have accordingly maintained that its interior portions are in a state of igneous fluidity. That our earth was once in such a condition, seems very probable. Such a theory is confirmed by many well attested facts. It has been demonstrated by many mathematical calculations, founded upon astronomical observations and actual measurements, that "the figure of the earth is an oblate spheriod, such as would be produced by revolution on its axis, provided the constituent matter of the globe were in such a state as to be allowed freely to arrange itself in obedience to the central and tangential forces."
The above, or an equivalent proposition, has often been demonstrated. The inference is, therefore, unavoidable, that the earth was once in a fluid state. It is true, the globe would have assumed very nearly the same figure that it now maintains, if it had originally consisted of a chaotic mass of earth and water, and those elements had been permitted to arrange themselves freely in obedience to the forces of attraction and revolution. But the positions of the external portions of land and water, would have been very different from those which they now occupy. Instead of being interspersed over the globe as they now are, there would have been a broad belt of water occupying the equatorial regions, while the land would have been confined to the northern and southern portions of the globe; for the revolutions of the globe on its axis, have given it an equatorial diameter about twenty-five miles greater than its polar; and if it had been originally composed of earth and water, it is evident that the water, yielding more freely to the centrifugal force, would have flowed up to the equatorial regions in order to give the earth its spheroidal form: so that we are obliged to have recourse to the former theory of the general fluidity of the earth—a fluidity maintained by the existence of an intense heat—as the only reason
