once been a burning orb, which had cooled down at the surface; yet, after all, this was only a theory, and there were other theories which were totally different. As a boy I had read wild works of fiction about lands in the interior of the earth, with a sun at the centre, which gave them the light of a perpetual day. These, I knew, were only the creations of fiction; yet, after all, it seemed possible that the earth might contain vast hollow spaces in its interior--realms of eternal darkness, caverns in comparison with which the hugest caves on the surface were but the tiniest cells. I was now being borne on to these. In that case there might be no sudden plunge, after all. The stream might run on for many thousand miles through this terrific cavern gloom, in accordance with natural laws; and I might thus live, and drift on in this darkness, until I should die a lingering death of horror and despair. There was no possible way of forming any estimate as to speed. All was dark, and even the glow behind was fading away; nor could I make any conjecture whatever as to the size of the channel. At the opening it had been contracted and narrow; but here it might have expanded itself to miles, and its vaulted top might reach almost to the summit of the lofty mountains. While sight thus failed me, sound was equally unavailing, for it was always the same--a sustained and unintermittent roar, a low, droning sound, deep and terrible, with no variations of dashing breakers or rushing rapids or falling cataracts. Vague thoughts of final escape came and went; but in such a situation hope could not be sustained. The thick darkness oppressed the soul; and at length even the glow of the distant volcanoes, which had been gradually diminishing, grew dimmer and fainter, and finally faded out altogether. That seemed to me to be my last sight of earthly things. After this nothing was left. There was no longer for me such a thing as sight; there was nothing but darkness--perpetual and eternal night. I was buried in a cavern of rushing waters, to which there would be no end, where I should be borne onward helplessly by the resistless tide to a mysterious and an appalling doom. The darkness grew so intolerable that I longed for something to dispel it, if only for a moment. I struck a match. The air was still, and the flame flashed out, lighting up the boat and showing the black water around me. This made me eager to see more. I loaded both barrels of the rifle, keeping my pistol for another purpose, and then fired one of them. There was a tremendous report, that rang in my ears like a hundred thunder-volleys, and rolled and reverberated far along, and died away in endless echoes. The flash lighted up the scene for an instant, and for an instant only; like the sudden lightning, it revealed all around. I saw a wide expanse of water, black as ink--a Stygian pool; but no rocks were visible, and it seemed as though I had been carried into a subterranean sea.