by Jules Verne
In fact, the mercury, which had gradually risen in the instrument as we descended, had stopped at twenty-nine inches.
“You see,” said the professor, “we only have a pressure of one atmosphere, and can’t wait for the manometer to take the place of the barometer.”
And indeed, this instrument would become useless as soon as the weight of the atmosphere exceeded the pressure at sea level.
“But,” I said, “isn’t there reason to fear that this steadily increasing pressure will become very painful?”
“No; we’ll descend at a slow pace, and our lungs will become used to breathing a denser atmosphere. Aeronauts lack air as they rise to high elevations, and we’ll perhaps have too much. But I prefer that. Let’s not waste a moment. Where’s the packet we sent down before us?”
I then remembered that we had searched for it in vain the evening before. My uncle questioned Hans who, after having looked around attentively with his hunter’s eyes, replied:
“Der huppe!”
“Up there.”
And so it was. The bundle had been caught by a projection a hundred feet above us. Immediately the agile Icelander climbed up like a cat, and in a few minutes the package was in our possession.
“Now,” said my uncle, “let’s have breakfast, but let’s have it like people who may have a long route in front of them.”
The biscuit and extract of meat were washed down with a draught of water mingled with a little gin.
Breakfast over, my uncle drew from his pocket a small notebook, intended for scientific observations. He consulted his instruments, and recorded:
Monday, July 1
Chronometer: 8.17 a.m.
Barometer: 29 7/12”.
Thermometer: 6°C.
Direction: E.S.E.
This last observation applied to the dark tunnel, and was indicated by the compass.
“Now, Axel,” exclaimed the professor with enthusiasm, “we’re really going into the bowels of the globe. At this precise moment the journey begins.”
That said, my uncle took the Ruhmkorff device that was hanging from his neck with one hand; and with the other he connected the electric current with the coil in the lantern, and a rather bright light dispersed the darkness of the passage.
Hans carried the other device, which was also turned on. This ingenious electrical appliance would enable us to go on for a long time by creating an artificial light even in the midst of the most inflammable gases.
“Let’s go!” exclaimed my uncle.
Each of us took his package. Hans pushed the load of cords and clothes before; and, myself going last, we entered the tunnel.
At the moment of penetrating into this dark tunnel, I raised my head, and saw for the last time through the length of that vast tube the sky of Iceland, “which I was never to behold again.”
The lava, in the last eruption of 1229, had forced a passage through this tunnel. It still lined the walls with a thick and glistening coat. The electric light was here intensified a hundredfold by reflection.
The only difficulty in advancing lay in not sliding too fast down an incline of about forty-five degrees; fortunately certain abrasions and a few blisters here and there formed steps, and we descended, letting our baggage slip before us from the end of a long rope.
But what made steps under our feet had turned into stalactites overhead. The lava, porous in some places, had taken the shape of small round blisters; opaque quartz crystals, decorated with limpid drops of glass and suspended like chandeliers from the vaulted roof, seemed to light up at our passage. It seemed as if the spirits of the abyss were illuminating their palace to receive their earthly guests.
“It’s magnificent!” I exclaimed spontaneously. “My uncle, what a sight! Don’t you admire these hues of lava, which blend from reddish brown to bright yellow by imperceptible gradations? And these crystals that seem to us like globes of light?”
“Ah! you’re coming around, Axel!” replied my uncle. “So you find this splendid, my boy! Well, you’ll see many others yet, I hope. Let’s go! Let’s go!”
He had better have said “slide,” for we did nothing but drop down the steep slopes. It was the facilis descensus Averni of Virgil.ao The compass, which I consulted frequently, gave our direction as southeast with inflexible steadiness. This lava stream deviated neither to the right nor to the left.
Yet there was no sensible increase in temperature. This justified Davy’s theory, and more than once I consulted the thermometer with surprise. Two hours after our departure it only showed 10°, an increase of only 4°. This was reason to believe that our descent was more horizontal than vertical. As for the exact depth we had reached, it was very easy to ascertain that; the professor measured the angles of deviation and inclination accurately on the road, but he kept the results of his observations to himself.
At about eight in the evening he signaled to stop. Hans sat down at once. The lamps were hung on a projection in the lava; we were in a sort of cavern where there was no lack of air. On the contrary. Certain breezes reached us. What caused them? That was a question I did not try to answer at the moment. Hunger and exhaustion made me incapable of reasoning. A descent of seven consecutive hours is not accomplished without considerable expenditure of strength. I was exhausted. The word ‘stop’ therefore gave me pleasure. Hans spread some provisions out on a block of lava, and we ate with a good appetite. But one thing troubled me; our supply of water was half consumed. My uncle counted on a fresh supply from underground sources, but so there had been none. I could not help drawing his attention to this issue.
“Are you surprised at this lack of springs?” he said.
“More than that, I’m anxious about it; we have only water enough for five days.”
“Don’t worry, Axel, I guarantee you that we’ll find water, and more than we’ll want.”
“When?”
“When we have left this layer of lava behind us. How can springs break through such walls as these?”
“But perhaps this passage runs to a very great depth. It seems to me that we’ve not yet made much progress vertically.”
“Why do you suppose that?”
“Because if we had advanced far into the crust of earth, it would be hotter.”
“According to your theory,” said my uncle. “What does the thermometer say?”
“Hardly 15°C, which means an increase of only 9° since our departure.”
“So, draw your conclusion.”
“This is my conclusion. According to exact observations, the temperature in the interior of the globe increases at the rate of 1° Celsius for every hundred feet. But certain local conditions may modify this rate. For example, at Yakutsk in Siberia it’s been observed that the increase of 1° takes place every 36 feet. This difference clearly depends on the heat-conducting power of the rocks. Moreover, in the neighborhood of an extinct volcano, through gneiss, it’s been observed that the increase of 1° is only attained every 125 feet. Let’s therefore assume this last hypothesis as the most appropriate for our situation, and calculate.”
“Do calculate, my boy.”
“Nothing’s easier,” I said, putting down figures in my notebook. “Nine times a hundred and twenty-five feet adds up to a depth of eleven hundred and twenty-five feet.”
“Very accurate indeed.”
“Well?”
“By my observation we are 10,000 feet below sea level.”
“Is that possible?”
“Yes, or numbers aren’t numbers anymore!”
The professor’s calculations were accurate. We had already reached a depth of six thousand feet beyond that so far reached by the foot of man, such as the mines of Kitzbühl in Tyrol, and those of Wuttemberg in Bohemia.
The temperature, which should have been 81°C in this place, was scarcely 15°. This was serious cause for reflection.
XIX
THE NEXT DAY, TUESDAY, June 30, at six in the morning, the descent began again.
W
e continued to follow the tunnel of lava, really a natural, gently sloping ramp like those inclined planes which are still found in old houses instead of staircases. And so we continued on until seventeen minutes past noon, the precise moment when we rejoined Hans, who had just stopped.
“Ah! here we are,” exclaimed my uncle, “at the very end of the chimney.”
I looked around me. We were standing at the intersection of two roads, both dark and narrow. Which one should we take? This was a difficulty.
But my uncle did not want to seem hesitant, either before me or the guide; he pointed to the Eastern tunnel, and all three of us were soon deep inside it.
In any case, any hesitation about this double path would have prolonged itself indefinitely, as there was no indicator to guide our choice of one or the other; we had to leave it absolutely to chance.
The slope of this tunnel was scarcely perceptible, and its sections very unequal. Sometimes we passed a series of arches succeeding each other like the majestic arcades of a gothic cathedral. Medieval artists could have studied all the forms of sacred architecture here that derive from the ogival arch. A mile farther we had to bow our heads under low arches in the Roman style, and massive pillars growing from the rock bent under the burden of the vaults. In certain places, this magnificence gave way to low structures which looked like beaver dams, and we had to crawl through narrow tubes.
The temperature remained bearable. Involuntarily I thought of the heat when the lava ejected from Snaefells was boiling and working through this now silent passage. I imagined the torrents of fire breaking at every turn in the tunnel, and the accumulation of overheated steam in this close environment!
“I only hope,” I thought, “that this old volcano doesn’t come up with any belated fantasies!”
I did not convey these fears to Professor Lidenbrock; he would not have understood them. His only idea was to move on. He walked, he slid, he even fell with a conviction that one could only admire.
By six in the evening, after an undemanding walk, we had gone two leagues south, but scarcely a quarter of a mile down.
My uncle gave the signal to rest. We ate without talking, and went to sleep without reflection.
Our arrangements for the night were very simple; a travel blanket into which we rolled ourselves was our only bedding. We had neither cold nor intrusive visits to fear. Travelers who penetrate into the wilds of central Africa, and into the pathless forests of the New World, are obliged to watch over each other by night. But here, absolute safety and utter seclusion. Savages or wild beasts, we did not need to fear any of these wicked species.
We awoke the next morning refreshed and in good spirits. We resumed the road. As on the previous day, we followed a lava path. Impossible to identify the nature of the rock it passed through. The tunnel, instead of leading down into the bowels of the globe, gradually became absolutely horizontal. I even thought I noticed that it rose again toward the surface of the earth. This tendency became so obvious at about ten in the morning, and therefore so tiring, that I was forced to slow down our pace.
“Well, Axel?” said the professor impatiently.
“Well, I can’t stand it any longer,” I replied.
“What! after three hours’ walk over such easy ground.”
“It may be easy, but it’s tiring all the same.”
“What, when we have nothing to do but keep going down!”
“Going up, if you please.”
“Going up!” said my uncle, with a shrug.
“No doubt. For the last half-hour the slopes have gone the other way, and at this rate we’ll go back to the surface of Iceland.”
The professor shook his head like a man who refuses to be convinced. I tried to resume the conversation. He answered not a word, and gave the signal for departure. I saw that his silence was nothing but concentrated bad humor.
Still I courageously shouldered my burden again, and rapidly followed Hans, whom my uncle preceded. I was anxious not to be left behind. My greatest care was not to lose sight of my companions. I shuddered at the thought of losing my way in the depths of this labyrinth.
Besides, if the ascending road became harder, I comforted myself by thinking that it was taking us closer to the surface. There was hope in this. Every step confirmed me in it, and I rejoiced at the thought of meeting my little Graüben again.
At noon there was a change in the appearance of the tunnel walls. I noticed it through a decrease in the amount of light that was reflected from the sides. Solid rock was replacing the lava coating. The mass was made up of slanted and sometimes vertical strata. We were passing through rocks of the Transition or Silurian system.ap
“It’s obvious,” I exclaimed, “marine deposits in the Secondary period have formed these shales, limestones, and sandstones! We’re turning away from the primary granite! We’re like people from Hamburg who go to Lübeck by way of Hanover!”aq
I should have kept my observations to myself. But my geological instinct was stronger than my prudence, and Uncle Lidenbrock heard my exclamation.
“What’s the matter?” he asked.
“Look,” I said, pointing to the varied succession of sandstones and limestones, and the first indication of slate.
“And?”
“We’re now in the period when the first plants and animals appeared.”
“Do you think so?”
“Well, look, examine it, study it!”
I forced the professor to move his lamp over the walls of the tunnel. I expected some outcry on his part. But he didn’t say a word, and continued on his way.
Had he understood me or not? Did he refuse to admit, out of self-love as an uncle and a scholar, that he had made a mistake when he chose the eastern tunnel, or was he determined to explore this passage to the end? It was obvious that we had left the lava path, and that this route could not possibly lead to the fiery core of the Snaefells.
Yet I wondered if I was not attributing too much importance to this change in the rock. Was I not myself mistaken? Were we really crossing layers of rock above the granite foundation?
“If I’m right,” I thought, “I should find some residue of primitive plants, and then we’ll have to acknowledge the evidence. Let’s look.”
I had not gone a hundred paces before incontestable proofs presented themselves. It could not be otherwise, for in the Silurian age the seas contained at least fifteen hundred vegetable and animal species. My feet, which had become accustomed to the hard lava ground, suddenly touched dust composed of plant and shell residue. In the walls were distinct impressions of fucus and lycopods.ar Professor Lidenbrock must have noticed; but he closed his eyes, I imagine, and pushed on with a steady step.
This was stubbornness pushed beyond all bounds. I could not hold out any longer. I picked up a perfectly formed shell, which had belonged to an animal not unlike the woodlouse; then, joining my uncle, I said:
“Look!”
“Very well,” he replied quietly, “it’s the shell of a crustacean, of an extinct species called a trilobite. Nothing more.”
“But don’t you conclude from this ... ?”
“What you yourself conclude? Yes. I do, perfectly. We’ve left the granite and the lava. It’s possible that I made a mistake. But I can’t be sure of that until I’ve reached the end of this tunnel.”
“You’re right in doing this, Uncle, and I’d approve if there were not a more and more threatening danger.”
“Which one?”
“The lack of water.”
“Well, Axel, we’ll put ourselves on rations.”
In the walls were distinct impressions of fucus and lycopods.
XX
INDEED, WE DID HAVE to ration ourselves. Our supply of water could not last more than three days. I found that out for certain when dinnertime came. Dismal prospect, we had little hope of finding a source in those rocks of the Transition period.
The whole next day the tunnel opened its endless arcades before us. We moved on
almost without a word. Hans’ silence spread to us.
The road was not ascending now, at least not perceptibly. Sometimes, it even seemed to slope downward. But this tendency, which was at any rate very slight, did not reassure the professor; for there was no change in the nature of the strata, and the Transition period became more and more manifest.
The electric light made the schist, the limestone, and old red sandstone of the walls glitter splendidly. One might have thought that we were passing through an open trench in Devonshire, the region whose name has been given to this kind of soil.as Magnificent marble specimens covered the walls, some of a grayish agate with veins fancifully outlined in white, others in a crimson color, or yellow dotted with spots of red; farther on, samples of dark cherry-red marbles in which limestone showed up in bright hues.
The greater part of this marble bore impressions of primitive organisms. Creation had made obvious progress since the previous day. Instead of rudimentary trilobites, I noticed remains of a more perfect order of beings, amongst others ganoid fishesat and some of those saurians in which paleontologists have discovered the earliest reptile forms. The Devonian seas were inhabited by animals of these species, and deposited them by thousands in the newly formed rocks.
It was obvious that we were ascending the scale of animal life in which man holds the highest place. But Professor Lidenbrock seemed not to care.
He was waiting for one of two events: either that a vertical well would be opening under his feet and allow him to resume his descent , or that an obstacle would prevent him from continuing on this route. But evening came, and this hope was not fulfilled.
On Friday, after a night during which I began to feel the pangs of thirst, our little troop again plunged into the winding passages of the tunnel.
After ten hours’ walking I noticed that the reflection of our lamps on the walls diminished strangely. The marble, the schist, the limestone, and the sandstone were giving way to a dark and lusterless lining. At one moment where the tunnel became very narrow, I leaned against the left wall.
