15. The depression of the poles and other conclusive facts are certain indications that the Earth had been originally in a fluid or soft state. This state could have been caused by matter having been liquefied by fire or softened by water.
It is proverbially said: “There is no smoke without fire.” This true proverb is an application of the principle: “There is no effect without a cause.” For the same reason one can say: “There is no fire without a focus.” Now, by facts which pass under our eyes, there is not only smoke produced, but also very real fire which must have a focus. This fire coming from the interior of the Earth, and not from on high, the focus must be within; the fire being permanent, the focus must be equally so.
The heat which is augmented by measure as it penetrates the interior of the Earth, and which at a certain distance from the surface attains a very high temperature; the hot springs, so much warmer according to the depth from which they come. Fires and masses of heated and burning substances, which escape from volcanoes with vast upheavings, or by crevasses produced by earthquakes, can leave no doubt concerning the existence of an interior fire.