that we had now long left Iceland behind us.
“What is the matter?” he cried.
“I was reflecting that if your calculations are correct we are no longer under Iceland.”
“Do you think so?”
“I am not mistaken,” I said, and examining the map, I added, “We have passed Cape Portland, and those fifty leagues bring us under the wide expanse of ocean.”
“Under the sea,” my uncle repeated, rubbing his hands with delight.
“Can it be?” I said. “Is the ocean spread above our heads?”
“Of course, Axel. What can be more natural? At Newcastle are there not coal mines extending far under the sea?”
It was all very well for the Professor to call this so simple, but I could not feel quite easy at the thought that the boundless ocean was rolling over my head. And yet it really mattered very little whether it was the plains and mountains that covered our heads, or the Atlantic waves, as long as we were arched over by solid granite. And, besides, I was getting used to this idea; for the tunnel, now running straight, now winding as capriciously in its inclines as in its turnings, but constantly preserving its southeasterly direction, and always running deeper, was gradually carrying us to very great depths indeed.
Four days later, Saturday, the 18th of July, in the evening, we arrived at a kind of vast grotto; and here my uncle paid Hans his weekly wages, and it was settled that the next day, Sunday, should be a day of rest.
Chapter XXV.
De Profundis
I therefore awoke next day relieved from the preoccupation of an immediate start. Although we were in the very deepest of known depths, there was something not unpleasant about it. And, besides, we were beginning to get accustomed to this troglodyte10 life. I no longer thought of sun, moon, and stars, trees, houses, and towns, nor of any of those terrestrial superfluities which are necessaries of men who live upon the earth’s surface. Being fossils, we looked upon all those things as mere jokes.
The grotto was an immense apartment. Along its granite floor ran our faithful stream. At this distance from its spring the water was scarcely tepid, and we drank of it with pleasure.
After breakfast the Professor gave a few hours to the arrangement of his daily notes.
“First,” said he, “I will make a calculation to ascertain our exact position. I hope, after our return, to draw a map of our journey, which will be in reality a vertical section of the globe, containing the track of our expedition.”
“That will be curious, uncle; but are your observations sufficiently accurate to enable you to do this correctly?”
“Yes; I have everywhere observed the angles and the inclines. I am sure there is no error. Let us see where we are now. Take your compass, and note the direction.”
I looked, and replied carefully:
“Southeast by east.”
“Well,” answered the Professor, after a rapid calculation, “I infer that we have gone eighty-five leagues since we started.!
“Therefore we are under mid-Atlantic?”
“To be sure we are.”
“And perhaps at this very moment there is a storm above, and ships over our heads are being rudely tossed by the tempest.”
“Quite probable.”
“And whales are lashing the roof of our prison with their tails?”
“It may be, Axel, but they won’t shake us here. But let us go back to our calculation. Here we are eighty-five leagues southeast of Snæfell, and I reckon that we are at a depth of sixteen leagues.”
“Sixteen leagues?” I cried.
“No doubt.”
“Why, this is the very limit assigned by science to the thickness of the crust of the earth.”
“I don’t deny it.”
“And here, according to the law of increasing temperature, there ought to be a heat of 2,732° Fahr.!”
“So there should, my lad.”
“And all this solid granite ought to be running in fusion.”
“You see that it is not so, and that, as so often happens, facts come to overthrow theories.”
“I am obliged to agree; but, after all, it is surprising.”
“What does the thermometer say?”
“Twenty-seven, six tenths (82° Fahr.).”
“Therefore the savants are wrong by 2,705°, and the proportional increase is a mistake. Therefore Humphry Davy was right, and I am not wrong in following him. What do you say now?”
“Nothing.”
In truth, I had a good deal to say. I gave way in no respect to Davy’s theory. I still held to the central heat, although I did not feel its effects. I preferred to admit in truth, that this chimney of an extinct volcano, lined with lavas, which are non-conductors of heat, did not suffer the heat to pass through its walls.
But without stopping to look up new arguments I simply took up our situation such as it was.
“Well, admitting all your calculations to be quite correct, you must allow me to draw one rigid result therefrom.”
“What is it. Speak freely.!
“At the latitude of Iceland, where we now are, the radius of the earth, the distance from the centre to the surface is about 1,583 leagues; let us say in round numbers 1,600 leagues, or 4,800 miles. Out of 1,600 leagues we have gone twelve!”
“So you say.”
“And these twelve at a cost of 85 leagues diagonally?”
“Exactly so.”
“In twenty days?”
“Yes.”
“Now, sixteen leagues are the hundredth part of the earth’s radius. At this rate we shall be two thousand days, or nearly five years and a half, in getting to the centre.”
No answer was vouchsafed to this rational conclusion. “Without reckoning, too, that if a vertical depth of sixteen leagues can be attained only by a diagonal descent of eighty-four, it follows that we must go eight thousand miles in a southeasterly direction; so that we shall emerge from some point in the earth’s circumference instead of getting to the centre!”
“Confusion
