Some author has remarked that, from the earliest times, there has been a loud cry of fire. We have seen that it began with the ancient Egyptians, and was continued by the Greeks. But in recent times it has waxed louder and far more distinct. The ancient notions about the existence of fire within the earth were almost entirely conjectural, but within the present century the matter has been put to the test of experiment. Wherever, in Europe and America, the temperature of the air, the waters, and the rocks in deep excavations has been ascertained, it has been found higher than the mean temperature of the climate at the surface; and the experiment has been made in hundreds of places. It is found, too, that the heat increases rapidly as we descend below that point in the earth's crust to which the sun's heat extends. The mean rate of increase has been stated by the British Association to be one degree of Fahrenheit for every forty-five feet. At this rate, all known rocks would be melted at the depth of about sixty miles. Shall we hence conclude that all the matter of the globe below this thickness (or, rather, for the sake of round numbers, below one hundred miles) is actually in a melted state? Most geologists have not seen how such a conclusion is to be avoided. And yet this would leave only about one eight hundredth part of the earth's diameter, and about one fourteenth of its contents, or bulk, in a solid state. How easy, then, should God give permission, for this vast internal fiery ocean to break through its envelope, and so to bury the solid crust that it should all be burnt up and melted! It is conceivable that such a result might take place even by natural operations. And certainly it would be easy for a special divine agency to accomplish it.