I had been carried into this darkness, through some vast opening which now lay behind me, disclosing the red volcano glow, and this it was that caused that roundness and resemblance to the moon.

I saw that I was still moving on away from that light as before, and that its changing position was due to the turning of the boat as the water drifted it along, now stern foremost, now sidewise, and again bow foremost.

From this it seemed plainly evident that the waters had borne me into some vast cavern of unknown extent, which went under the mountains--a subterranean channel, whose issue I could not conjecture.

Was this the beginning of that course which should ultimately become a plunge deep down into some unutterable abyss?
or might I ever hope to emerge again into the light of day--perhaps in some other ocean--some land of ice and frost and eternal night?
But the old theory of the flow of water through the earth had taken hold of me and could not be shaken off.

I knew some scientific men held the opinion that the earth's interior is a mass of molten rock and pent-up fire, and that the earth itself had 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.