The investigations which have been made, and the evidence which has been brought together, render it undeniable that the lower parts of the earth are on fire. Of the intensity of the combustion, no practical idea can be formed. It is fearful beyond comparison. The lava thrown out from a volcano in Mexico, “was so hot that it continued to smoke for twenty years; and after three years and a half, a piece of wood took fire in it, at a distance of five miles from the crater.” In various parts of the world, large islands have been thrown up from the sea, in a red-hot glowing condition, and so intensely heated, that after being forced through many fathoms of salt water, and standing in the midst of it, exposed to wind and rain for several months, they were not sufficiently cooled for persons to approach and stand upon them. “A notable fact is the force exerted in volcanic action, Cotopaxi, in 1738, threw its fiery rockets 3,000 feet above its crater, while in 1744 the blazing mass, struggling for an outlet, roared like a furnace, so that its awful voice was heard at a distance of more than six hundred miles. In 1797, the crater of Tunguragua, one of the great peaks of the Andes, flung out torrents of mud, which dammed up rivers, opened new lakes, and in valleys of a thousand feet wide made deposits six hundred feet deep. The stream from Vesuvius which, in 1737, passed through Torre del Greco, contained thirty-three million cubic feet of solid matter; and, in 1794, when Torre del Greco was destroyed a second time, the mass of lava amounted to forty-five million cubic feet. In 1669 Etna poured forth a flood which covered 84 square miles of surface, and measured nearly 100,000,000 cubic feet. On this occasion the sand and scoriæ formed the Monte Rossi, near Nicolosi, a cone two miles in circumference, and four hundred and fifty feet high. The stream thrown out by Etna, in 1819, was in motion, at the rate of a yard per day, for nine months after the eruption; and it is on record that the lavas of the same mountain, after a terrible eruption, were not thoroughly cooled and consolidated ten years after the event. In the eruption of Vesuvius, A.D. 79, the scoriæ and ashes vomited forth far exceeded the entire bulk of the mountain; while, in 1660, Etna disgorged more than twenty times its own mass. * * * Vesuvius has thrown its ashes as far as Constantinople, Syria, and Egypt; it hurled stones eight pounds in weight to Pompeii, a distance of six miles; while similar masses were tossed up 2,000 feet above its summit. Cotopaxi has projected a block one hundred cubic yards in volume a distance of nine miles, while Sumbawa, in 1815, during the most terrible eruption on record, sent its ashes as far as Java, a distance of three hundred miles. * * * In viewing these evidences of enormous power, we are forcibly struck with the similarity of action with which they have been associated; and, carrying our investigation