to each sixty to seventy feet depth, would be sufficient to fuse the most refractory substances at that distance beneath the surface. Another finds that the phenomena of precession and nutation require that the earth, if not entirely solid, must at least have a shell not less than eight hundred to a thousand miles in thickness. So there you are. You may take your choice."

"And if it should prove solid?" I asked.

"It will be all the same to us in the end, David," replied Perry. "At the best our fuel will suffice to carry us but three or four days, while our atmosphere cannot last to exceed three. Neither, then, is sufficient to bear us in safety through eight thousand miles of rock to the antipodes."

"If the crust is of sufficient thickness we shall come to a final stop between six and seven hundred miles beneath the earth's surface; but during the last hundred and fifty miles of our journey we shall be corpses. Am I correct?" I asked.

"Quite correct, David. Are you frightened?"

"I do not know. It all has come so suddenly that I scarce believe that either of us realizes the real terrors of our position. I feel that I should be reduced to panic; but yet I am not. I imagine that the shock has been so great as to partially stun our sensibilities."

Again I turned to the thermometer. The mercury was rising with less rapidity. It was now but 140 degrees, although we had penetrated to a depth of nearly four miles. I told Perry, and he smiled.

"We have shattered one theory at least," was his only comment, and then he returned to his self-assumed occupation of fluently cursing the steering wheel. I once heard a pirate swear, but his best efforts would have seemed like those of a tyro alongside of Perry's masterful and scientific imprecations.

Once more I tried my hand at the wheel, but I might as well have essayed to swing the earth itself. At my suggestion Perry stopped the generator, and as we came to rest I again threw all my strength into a supreme effort to move the thing even a hair's breadth—but the results were as barren as when we had been traveling at top speed.

I shook my head sadly, and motioned to the starting lever. Perry pulled it toward him, and once again we were plunging downward toward eternity at the rate of seven miles an hour. I sat with my eyes glued to the thermometer and the distance meter. The mercury was rising very slowly now, though even at 145 degrees it was almost unbearable within the narrow confines of our metal prison.

About noon, or twelve hours after our start upon this unfortunate journey, we had bored to a depth of eighty-four miles, at which point the mercury registered 153 degrees F.

Perry was becoming more hopeful, although upon what meager food he sustained his optimism I could not conjecture. From cursing he had turned to singing—I felt that the strain had at last affected his mind. For several hours we had not spoken except as he asked me for the readings of the instruments from time to time, and I announced them. My thoughts were filled with vain regrets. I recalled numerous acts of my past life which I should have been glad to have had a few more years to live down. There was the affair in the Latin Commons at Andover when Calhoun and I had put gunpowder in the stove—and nearly killed one of the masters. And then—but what was the use, I was about to die and atone for all these things and several more. Already the heat was sufficient to give me a foretaste of the hereafter. A few more degrees and I felt that I should lose consciousness.

"What are the readings now, David?" Perry's voice broke in upon my somber reflections.

"Ninety miles and 153 degrees," I replied.

"Gad, but we've knocked that thirty-mile-crust theory into a cocked hat!" he cried gleefully.

"Precious lot of good it will do us," I growled back.

"But my boy," he continued, "doesn't that temperature reading mean anything to you? Why it hasn't gone up in six miles. Think of it, son!"

"Yes, I'm thinking of it," I answered; "but what difference will it make when our air supply is exhausted whether the temperature is 153 degrees or 153,000? We'll be just as dead, and no one will know the difference, anyhow." But I must admit that for some unaccountable reason the stationary temperature did renew my waning hope. What I hoped for I could not have explained, nor did I try. The very fact, as Perry took pains to explain, of the blasting of several very exact and learned scientific hypotheses made it apparent that we could not know what lay before us within the bowels of the earth, and so we might continue to hope for the best, at least until we were dead—when hope would no longer be essential to our happiness. It was very good, and logical reasoning, and so I embraced it.

At one hundred miles the temperature had DROPPED TO 152 1/2 DEGREES! When I announced it Perry reached over and hugged me.

From then on until noon of the second day, it continued to drop until it became as uncomfortably cold as it had been unbearably hot before. At the depth of two hundred and forty miles our nostrils were assailed by almost overpowering ammonia fumes, and the temperature had dropped to TEN BELOW ZERO! We suffered nearly two hours of this intense and bitter cold, until at about two hundred and forty-five miles from the surface of the earth we entered a stratum of solid ice, when the mercury quickly rose to 32 degrees. During the next three hours we passed through ten miles of ice, eventually emerging into another series of ammonia-impregnated strata, where the mercury again fell to ten degrees below zero.

Slowly it rose once more until we were convinced that at last we were nearing the molten interior of the earth. At four hundred miles the temperature had reached 153 degrees. Feverishly I watched the thermometer. Slowly it rose. Perry had ceased singing and was at last praying.

Our hopes had received such a deathblow that the gradually increasing heat seemed to our distorted imaginations much greater than it really was. For another hour I saw that pitiless column of mercury rise and rise until at four hundred and ten miles it stood at 153 degrees. Now it was that we began to hang upon those readings in almost breathless anxiety.

One hundred and fifty-three degrees had been the maximum temperature above the ice stratum. Would it stop at this point again, or would it continue its merciless climb? We knew that there was no hope, and yet with the persistence of life itself we continued to hope against practical certainty.

Already the air tanks were at low ebb—there was barely enough of the precious gases to sustain us for another twelve hours. But would we be alive to know or care? It seemed incredible.

At four hundred and twenty miles I took another reading.

"Perry!" I shouted. "Perry, man! She's going down! She's going down! She's 152 degrees again."

"Gad!" he cried. "What can it mean? Can the earth be cold at the center?"

"I do not know, Perry," I answered; "but thank God, if I am to die it shall not be by fire—that is all that I have feared. I can face the thought of any death but that."

Down, down went the mercury until it stood as low as it had seven miles from the surface of the earth, and then of a sudden the realization broke upon us that death was very near. Perry was the first to discover it. I saw him fussing with the valves that regulate the air supply. And at the same time I experienced difficulty in breathing. My head felt dizzy—my limbs heavy.

I saw Perry crumple in his seat. He gave himself a shake and sat erect again. Then he turned toward me.

"Good-bye, David," he said. "I guess this is the end," and then he smiled and closed his eyes.

"Good-bye, Perry, and good luck to you," I answered, smiling back at him. But I fought off that awful lethargy. I was very young—I did not want to die.

For an hour I battled against the cruelly enveloping death that surrounded me upon all sides. At first I found that by climbing