A Journey to the Interior of the Earth

CHAPTER XVIII.

THE WON­DERS OF TER­RES­TRI­AL DEPTHS

At eight in the morn­ing a ray of day­light came to wake us up. The thou­sand shin­ing sur­faces of la­va on the walls re­ceived it on its pas­sage, and scat­tered it like a show­er of sparks.

There was light enough to dis­tin­guish sur­round­ing ob­jects.

“Well, Ax­el, what do you say to it?” cried my un­cle, rub­bing his hands. “Did you ev­er spend a qui­eter night in our lit­tle house at Königs­berg? No noise of cart wheels, no cries of bas­ket wom­en, no boat­men shout­ing!”

“No doubt it is very qui­et at the bot­tom of this well, but there is some­thing alarm­ing in the quiet­ness it­self.”

“Now come!” my un­cle cried; “if you are fright­ened al­ready, what will you be by and by? We have not gone a sin­gle inch yet in­to the bow­els of the earth.”

“What do you mean?”

“I mean that we have on­ly reached the lev­el of the is­land. long ver­ti­cal tube, which ter­mi­nates at the mouth of the crater, has its low­er end on­ly at the lev­el of the sea.”

“Are you sure of that?”

“Quite sure. Con­sult the barom­eter.”

In fact, the mer­cury, which had risen in the in­stru­ment as fast as we de­scend­ed, had stopped at twen­ty-​nine inch­es.

“You see,” said the Pro­fes­sor, “we have now on­ly the pres­sure of our at­mo­sphere, and I shall be glad when the aneroid takes the place of the barom­eter.”

And in truth this in­stru­ment would be­come use­less as soon as the weight of the at­mo­sphere should ex­ceed the pres­sure as­cer­tained at the lev­el of the sea.

“But,” I said, “is there not rea­son to fear that this ev­er-​in­creas­ing pres­sure will be­come at last very painful to bear?”

“No; we shall de­scend at a slow rate, and our lungs will be­come in­ured to a denser at­mo­sphere. Aero­nauts find the want of air as they rise to high el­eva­tions, but we shall per­haps have too much: of the two, this is what I should pre­fer. Don’t let us lose a mo­ment. Where is the bun­dle 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 ex­am­ined at­ten­tive­ly with the eye of a hunts­man, replied:

“_Der huppe!_”

“Up there.”

And so it was. The bun­dle had been caught by a pro­jec­tion a hun­dred feet above us. Im­me­di­ate­ly the Ice­lander climbed up like a cat, and in a few min­utes the pack­age was in our pos­ses­sion.

“Now,” said my un­cle, “let us break­fast; but we must lay in a good stock, for we don’t know how long we may have to go on.”

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, 297 in.; ther­mome­ter, 6° (43° F.). Di­rec­tion, E.S.E.”

This last ob­ser­va­tion ap­plied to the dark gallery, and was in­di­cat­ed by the com­pass.

“Now, Ax­el,” cried the Pro­fes­sor with en­thu­si­asm, “now we are re­al­ly go­ing in­to the in­te­ri­or of the earth. At this pre­cise mo­ment the jour­ney com­mences.”

So say­ing, my un­cle took in one hand Ruhmko­rff’s ap­pa­ra­tus, which was hang­ing from his neck; and with the oth­er he formed an elec­tric com­mu­ni­ca­tion with the coil in the lantern, and a suf­fi­cient­ly bright light dis­persed the dark­ness of the pas­sage.

Hans car­ried the oth­er ap­pa­ra­tus, which was al­so put in­to ac­tion. This in­ge­nious ap­pli­ca­tion of elec­tric­ity would en­able us to go on for a long time by cre­at­ing an ar­ti­fi­cial light even in the midst of the most in­flammable gas­es.

“Now, march!” cried my un­cle.

Each shoul­dered his pack­age. Hans drove be­fore him the load of cords and clothes; and, my­self walk­ing last, we en­tered the gallery.

At the mo­ment of be­com­ing en­gulfed in this dark gallery, 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 pro­ceed­ing lay in not slid­ing too fast down an in­cline of about forty-​five de­grees; hap­pi­ly cer­tain as­per­ities and a few blis­ter­ings here and there formed steps, and we de­scend­ed, let­ting our bag­gage slip be­fore us from the end of a long rope.

But that which formed steps un­der our feet be­came sta­lac­tites over­head. The la­va, which was porous in many places, had formed a sur­face cov­ered with small round­ed blis­ters; crys­tals of opaque quartz, set with limpid tears of glass, and hang­ing like clus­tered chan­de­liers from the vault­ed roof, seemed as it were to kin­dle and form a sud­den il­lu­mi­na­tion as we passed on our way. It seemed as if the genii of the depths were light­ing up their palace to re­ceive their ter­res­tri­al guests.

“It is mag­nif­icent!” I cried spon­ta­neous­ly. “My un­cle, what a sight! Don’t you ad­mire those blend­ing hues of la­va, pass­ing from red­dish brown to bright yel­low by im­per­cep­ti­ble shades? And these crys­tals are just like globes of light.”

“Ali, you think so, do you, Ax­el, my boy? Well, you will see greater splen­dours than these, I hope. Now let us march: march!”

He had bet­ter have said slide, for we did noth­ing but drop down the steep in­clines. It was the facifs _de­scen­sus Av­erni_ of Vir­gil. 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 of tem­per­ature. This jus­ti­fied Davy’s the­ory, and more than once I con­sult­ed the ther­mome­ter with sur­prise. Two hours af­ter our de­par­ture it on­ly marked 10° (50° Fahr.), an in­crease of on­ly 4°. This gave rea­son for be­liev­ing that our de­scent was more hor­izon­tal than ver­ti­cal. As for the ex­act depth reached, it was very easy to as­cer­tain that; the Pro­fes­sor mea­sured ac­cu­rate­ly the an­gles of de­vi­ation and in­cli­na­tion on the road, but he kept the re­sults to him­self.

About eight in the evening he sig­nalled to stop. Hans sat down at once. The lamps were hung up­on a pro­jec­tion in the la­va; we were in a sort of cav­ern where there was plen­ty of air. Cer­tain puffs of air reached us. What at­mo­spher­ic dis­tur­bance was the cause of them? I could not an­swer that ques­tion at the mo­ment. Hunger and fa­tigue made me in­ca­pable of rea­son­ing. A de­scent of sev­en hours con­sec­utive­ly is not made with­out con­sid­er­able ex­pen­di­ture of strength. I was ex­haust­ed. The or­der to ‘halt’ there­fore gave me plea­sure. Hans laid our pro­vi­sions up­on 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 reck­oned up­on a fresh sup­ply from sub­ter­ranean sources, but hith­er­to we had met with none. I could not help draw­ing his at­ten­tion to this cir­cum­stance.

“Are you sur­prised at this want of springs?” he said.

“More than that, I am anx­ious about it; we have on­ly wa­ter enough for five days.”

“Don’t be un­easy, Ax­el, we shall find more than we want.”

“When?”

“When we have left this bed of la­va be­hind us. How could springs break through such walls as these?”

“But per­haps this pas­sage runs to a very great depth. It seems to me that we have made no great progress ver­ti­cal­ly.”

“Why do you sup­pose that?”

“Be­cause if we had gone deep in­to the crust of earth, we should have en­coun­tered greater heat.”

“Ac­cord­ing to your sys­tem,” said my un­cle. “But what does the ther­mome­ter say?”

“Hard­ly fif­teen de­grees (59° Fahr), nine de­grees on­ly since our de­par­ture.”

“Well, what is your con­clu­sion?”

“This is my con­clu­sion. Ac­cord­ing to ex­act ob­ser­va­tions, the in­crease of tem­per­ature in the in­te­ri­or of the globe ad­vances at the rate of one de­gree (1 4/5° Fahr.) for ev­ery hun­dred feet. But cer­tain lo­cal con­di­tions may mod­ify this rate. Thus at Yak­out­sk in Siberia the in­crease of a de­gree is as­cer­tained to be reached ev­ery 36 feet. This dif­fer­ence de­pends up­on the heat-​con­duct­ing pow­er of the rocks. More­over, in the neigh­bour­hood of an ex­tinct vol­cano, through gneiss, it has been ob­served that the in­crease of a de­gree is on­ly at­tained at ev­ery 125 feet. Let us there­fore as­sume this last hy­poth­esis as the most suit­able to our sit­ua­tion, and cal­cu­late.”

“Well, do cal­cu­late, my boy.”

“Noth­ing is eas­ier,” said I, putting down fig­ures in my note book. “Nine times a hun­dred and twen­ty-​five feet gives a depth of eleven hun­dred and twen­ty-​five feet.”

“Very ac­cu­rate in­deed.”

“Well?”

“By my ob­ser­va­tion we are at 10,000 feet be­low the lev­el of the sea.”

“Is that pos­si­ble?”

“Yes, or fig­ures are of no use.”

The Pro­fes­sor’s cal­cu­la­tions were quite cor­rect. We had al­ready at­tained a depth of six thou­sand feet be­yond that hith­er­to reached by the foot of man, such as the mines of Kitz Bahl in Ty­rol, and those of Wut­tem­bourg in Bo­hemia.

The tem­per­ature, which ought to have been 81° (178° Fahr.) was scarce­ly 15° (59° Fahr.). Here was cause for re­flec­tion.