"Now look at your aneroid. What does that say?"
"It says we are under considerable pressure."
"Very good; so you see that by going gradually down, and getting accustomed to the density of the atmosphere, we don't suffer at all."
"Nothing, except a little pain in the ears."
"That's nothing, and you may get rid of even that by quick breathing whenever you feel the pain."
"Exactly so," I said, determined not to say a word that might cross my uncle's prejudices. "There is even positive pleasure in living in this dense atmosphere. Have you observed how intense sound is down here?"
"No doubt it is. A deaf man would soon learn to hear perfectly."
"But won't this density augment?"
"Yes; according to a rather obscure law. It is well known that the weight of bodies diminishes as fast as we descend. You know that it is at the surface of the globe that weight is most sensibly felt, and that at the centre there is no weight at all."
"I am aware of that; but, tell me, will not air at last acquire the density of water?"
"Of course, under a pressure of seven hundred and ten atmospheres."
"And how, lower down still?"
"Lower down the density will still increase."
"But how shall we go down then."
"Why, we must fill our pockets with stones."
"Well, indeed, my worthy uncle, you are never at a loss for an answer."
I dared venture no farther into the region of probabilities, for I might presently have stumbled upon an impossibility, which would have brought the Professor on the scene when he was not wanted.
Still, it was evident that the air, under a pressure which might reach that of thousands of atmospheres, would at last reach the solid state, and then, even if our bodies could resist the strain, we should be stopped, and no reasonings would be able to get us on any farther.
But I did not advance this argument. My uncle would have met it with his inevitable Saknussemm, a precedent which possessed no weight with me; for even if the journey of the learned Icelander were really attested, there was one very simple answer, that in the sixteenth century there was neither barometer or aneroid and therefore Saknussemm could not tell how far he had gone.
But I kept this objection to myself, and waited the course of events.
The rest of the day was passed in calculations and in conversations. I remained a steadfast adherent of the opinions of Professor Liedenbrock, and I envied the stolid indifference of Hans, who, without going into causes and effects, went on with his eyes shut wherever his destiny guided him.
THE WORST PERIL OF ALL
It must be confessed that hitherto things had not gone on so badly, and that I had small reason to complain. If our difficulties became no worse, we might hope to reach our end. And to what a height of scientific glory we should then attain! I had become quite a Liedenbrock in my reasonings; seriously I had. But would this state of things last in the strange place we had come to? Perhaps it might.
For several days steeper inclines, some even frightfully near to the perpendicular, brought us deeper and deeper into the mass of the interior of the earth. Some days we advanced nearer to the centre by a league and a half, or nearly two leagues. These were perilous descents, in which the skill and marvellous coolness of Hans were invaluable to us. That unimpassioned Icelander devoted himself with incomprehensible deliberation; and, thanks to him, we crossed many a dangerous spot which we should never have cleared alone.
But his habit of silence gained upon him day by day, and was infecting us. External objects produce decided effects upon the brain. A man shut up between four walls soon loses the power to associate words and ideas together. How many prisoners in solitary confinement become idiots, if not mad, for want of exercise for the thinking faculty!
During the fortnight following our last conversation, no incident occurred worthy of being recorded. But I have good reason for remembering one very serious event which took place at this time, and of which I could scarcely now forget the smallest details.