But it is likewise the creed adopted by other distinguished geologists, that the interior of the globe is neither gas nor water, nor any of the heaviest minerals known, for in none of these cases would the earth weigh what it does."
"Oh, with figures you may prove anything!"
"But is it the same with facts! Is it not known that the number of volcanoes has diminished since the first days of creation? and if there is central heat may we not thence conclude that it is in process of diminution?"
"My good uncle, if you will enter into the legion of speculation, I can discuss the matter no longer."
"But I have to tell you that the highest names have come to the support of my views. Do you remember a visit paid to me by the celebrated chemist, Humphry Davy, in 1825?"
"Not at all, for I was not born until nineteen years afterwards."
"Well, Humphry Davy did call upon me on his way through Hamburg. We were long engaged in discussing, amongst other problems, the hypothesis of the liquid structure of the terrestrial nucleus. We were agreed that it could not be in a liquid state, for a reason which science has never been able to confute."
"What is that reason?" I said, rather astonished.
"Because this liquid mass would be subject, like the ocean, to the lunar attraction, and therefore twice every day there would be internal tides, which, upheaving the terrestrial crust, would cause periodical earthquakes!"
"Yet it is evident that the surface of the globe has been subject to the action of fire," I replied, "and it is quite reasonable to suppose that the external crust cooled down first, whilst the heat took refuge down to the centre."
"Quite a mistake," my uncle answered. "The earth has been heated by combustion on its surface, that is all. Its surface was composed of a great number of metals, such as potassium and sodium, which have the peculiar property of igniting at the mere contact with air and water; these metals kindled when the atmospheric vapours fell in rain upon the soil; and by and by, when the waters penetrated into the fissures of the crust of the earth, they broke out into fresh combustion with explosions and eruptions. Such was the cause of the numerous volcanoes at the origin of the earth."
"Upon my word, this is a very clever hypothesis," I exclaimed, in spite rather of myself.
"And which Humphry Davy demonstrated to me by a simple experiment. He formed a small ball of the metals which I have named, and which was a very fair representation of our globe; whenever he caused a fine dew of rain to fall upon its surface, it heaved up into little monticules, it became oxydized and formed miniature mountains; a crater broke open at one of its summits; the eruption took place, and communicated to the whole of the ball such a heat that it could not be held in the hand."
In truth, I was beginning to be shaken by the Professor's arguments, besides which he gave additional weight to them by his usual ardour and fervent enthusiasm.
"You see, Axel," he added, "the condition of the terrestrial nucleus has given rise to various hypotheses among geologists; there is no proof at all for this internal heat; my opinion is that there is no such thing, it cannot be; besides we shall see for ourselves, and, like Arne Saknussemm, we shall know exactly what to hold as truth concerning this grand question."
"Very well, we shall see," I replied, feeling myself carried off by his contagious enthusiasm. "Yes, we shall see; that is, if it is possible to see anything there."
"And why not? May we not depend upon electric phenomena to give us light? May we not even expect light from the atmosphere, the pressure of which may render it luminous as we approach the centre?"
"Yes, yes," said I; "that is possible, too."
"It is certain," exclaimed my uncle in a tone of triumph. "But silence, do you hear me? silence upon the whole subject; and let no one get before us in this design of discovering the centre of the earth."
Chapter VII.
A woman's courage
Thus ended this memorable seance. That conversation threw me into a fever. I came out of my uncle's study as if I had been stunned, and as if there was not air enough in all the streets of Hamburg to put me right again. I therefore made for the banks of the Elbe, where the steamer lands her passengers, which forms the communication between the city and the Hamburg railway.
Was I convinced of the truth of what I had heard? Had I not bent under the iron rule of the Professor Liedenbrock? Was I to believe him in earnest in his intention to penetrate to the centre of this massive globe? Had I been listening to the mad speculations of a lunatic, or to the scientific conclusions of a lofty genius? Where did truth stop? Where did error begin?
I was all adrift amongst a thousand contradictory hypotheses, but I could not lay hold of one.
Yet I remembered that I had been convinced, although now my enthusiasm was beginning to cool down; but I felt a desire to start at once, and not to lose time and courage by calm reflection. I had at that moment quite courage enough to strap my knapsack to my shoulders and start.
But I must confess that in another hour this unnatural excitement abated, my nerves became unstrung, and from the depths of the abysses of this earth I ascended to its surface again.
"It is quite absurd!" I cried, "there is no sense about it. No sensible young man should for a moment entertain such a proposal. The whole thing is non-existent. I have had a bad night, I have been dreaming of horrors."
But I had followed the banks of the Elbe and passed the town. After passing the port too, I had reached the Altona road. I was led by a presentiment, soon to be realised; for shortly I espied my little Gräuben bravely returning with her light step to Hamburg.
"Gräuben!" I cried from afar off.
The young girl stopped, rather frightened perhaps to hear her name called after her on the high road. Ten yards more, and I had joined her.
"Axel!" she cried surprised. "What! have you come to meet me? Is this why you are here, sir?"
But when she had looked upon me, Gräuben could not fail to see the uneasiness and distress of my mind.
"What is the matter?" she said, holding out her hand.
"What is the matter, Gräuben?" I cried.
In a couple of minutes my pretty Virlandaise was fully informed of the position of affairs. For a time she was silent. Did her heart palpitate as mine did? I don't know about that, but I know that her hand did not tremble in mine. We went on a hundred yards without speaking.
At last she said, "Axel!"
"My dear Gräuben."
"That will be a splendid journey!"
I gave a bound at these words.
"Yes, Axel, a journey worthy of the nephew of a savant; it is a good thing for a man to be distinguished by some great enterprise."
"What, Gräuben, won't you dissuade me from such an undertaking?"
"No, my dear Axel, and I would willingly go with you, but that a poor girl would only be in your way."
"Is that quite true?"
"It is true."
Ah! women and young girls, how incomprehensible are your feminine hearts! When you are not the timidest, you are the bravest of creatures. Reason has nothing to do with your actions. What! did this child encourage me in such an expedition! Would she not be afraid to join it herself? And she was driving me to it, one whom she loved!
I was disconcerted, and, if I must tell the whole truth, I was ashamed.
"Gräuben, we will see whether you will say the same thing to-morrow."
"To-morrow, dear Axel, I will say what I say to-day."
Gräuben and I, hand in hand, but in silence, pursued our way. The emotions of that day were breaking my heart.
After all, I thought, the kalends of July are a long