CHAPTER EIGHTEEN.

  REFLECTIONS OF THE COLONISTS--THEIR LABOURS OF RECONSTRUCTION RESUMED--THE 1ST OF JANUARY 1869--A CLOUD OVER THE SUMMIT OF THE VOLCANO--FIRSTWARNINGS OF AN ERUPTION--AYRTON AND CYRUS HARDING AT THE CORRAL--EXPLORATION OF THE DAKKAR GROTTO--WHAT CAPTAIN NEMO HAD CONFIDED TO THEENGINEER.

  At break of day the colonists regained in silence the entrance of thecavern, to which they gave the name of "Dakkar Grotto," in memory ofCaptain Nemo. It was now low-water, and they passed without difficultyunder the arcade, washed on the right by the sea.

  The canoe was left here, carefully protected from the waves. As anexcess of precaution, Pencroft, Neb, and Ayrton drew it up on a littlebeach which bordered one of the sides of the grotto, in a spot where itcould run no risk of harm.

  The storm had ceased during the night. The last low mutterings of thethunder died away in the west. Rain fell no longer, but the sky was yetobscured by clouds. On the whole, this month of October, the first ofthe southern spring, was not ushered in by satisfactory tokens, and thewind had a tendency to shift from one point of the compass to another,which rendered it impossible to count upon settled weather.

  Cyrus Harding and his companions, on leaving Dakkar Grotto, had takenthe road to the corral. On their way Neb and Herbert were careful topreserve the wire which had been laid down by the captain between thecorral and the grotto, and which might at a future time be of service.

  The colonists spoke but little on the road. The various incidents ofthe night of the 15th October had left a profound impression on theirminds. The unknown being whose influence had so effectually protectedthem, the man whom their imagination had endowed with supernaturalpowers, Captain Nemo, was no more. His _Nautilus_ and he were buried inthe depths of the abyss. To each one of them their existence seemedeven more isolated than before. They had been accustomed to count uponthe intervention of that power which existed no longer, and GideonSpilett, and even Cyrus Harding, could not escape this impression. Thusthey maintained a profound silence during their journey to the corral.

  Towards nine in the morning the colonists arrived at Granite House.

  It had been agreed that the construction of the vessel should beactively pushed forward, and Cyrus Harding more than ever devoted histime and labour to this object. It was impossible to divine what futurelay before them. Evidently the advantage to the colonists would begreat of having at their disposal a substantial vessel, capable ofkeeping the sea even in heavy weather, and large enough to attempt, incase of need, a voyage of some duration. Even if, when their vesselshould be completed, the colonists should not resolve to leave LincolnIsland as yet, in order to gain either one of the Polynesianarchipelagos of the Pacific or the shores of New Zealand, they might atleast, sooner or later, proceed to Tabor Island, to leave there thenotice relating to Ayrton. This was a precaution rendered indispensableby the possibility of the Scotch yacht reappearing in those seas, and itwas of the highest importance that nothing should be neglected on thispoint.

  The works were then resumed. Cyrus Harding, Pencroft, and Ayrton,assisted by Neb, Gideon Spilett, and Herbert, except when unavoidablycalled off by other necessary occupations, worked without cessation. Itwas important that the new vessel should be ready in five months--thatis to say, by the beginning of March--if they wished to visit TaborIsland before the equinoctial gales rendered the voyage impracticable.Therefore the carpenters lost not a moment. Moreover, it wasunnecessary to manufacture rigging, that of the _Speedy_ having beensaved entire, so that the hull only of the vessel needed to beconstructed.

  The end of the year 1868 found them occupied by these important labours,to the exclusion of almost all others. At the expiration of two monthsand a half the ribs had been set up and the first planks adjusted. Itwas already evident that the plans made by Cyrus Harding were admirable,and that the vessel would behave well at sea.

  Pencroft brought to the task a devouring energy, and scrupled not togrumble when one or the other abandoned the carpenter's axe for the gunof the hunter. It was nevertheless necessary to keep up the stores ofGranite House, in view of the approaching winter. But this did notsatisfy Pencroft. The brave honest sailor was not content when theworkmen were not at the dockyard. When this happened he grumbledvigorously, and, by way of venting his feelings, did the work of sixmen.

  The weather was very unfavourable during the whole of the summer season.For some days the heat was overpowering, and the atmosphere, saturatedwith electricity, was only cleared by violent storms. It was rarelythat the distant growling of the thunder could not be heard, like a lowbut incessant murmur, such as is produced in the equatorial regions ofthe globe.

  The 1st of January, 1869, was signalised by a storm of extreme violence,and the thunder burst several times over the island. Large trees werestruck by the electric fluid and shattered, and among others one ofthose gigantic micocouliers which shaded the poultry-yard at thesouthern extremity of the lake. Had this meteor any relation to thephenomena going on in the bowels of the earth? Was there any connectionbetween the commotion of the atmosphere and that of the interior of theearth? Cyrus Harding was inclined to think that such was the case, forthe development of these storms was attended by the renewal of volcanicsymptoms.

  It was on the 3rd of January that Herbert, having ascended at daybreakto the plateau of Prospect Heights to harness one of the onagas,perceived an enormous hat-shaped cloud rolling from the summit of thevolcano.

  Herbert immediately apprised the colonists, who at once joined him inwatching the summit of Mount Franklin.

  "Ah!" exclaimed Pencroft, "those are not vapours this time! It seems tome that the giant is not content with breathing; he must smoke!"

  This figure of speech employed by the sailor exactly expressed thechanges going on at the mouth of the volcano. Already for three monthshad the crater emitted vapours more or less dense, but which were as yetproduced only by an internal ebullition of mineral substances. But nowthe vapours were replaced by a thick smoke, rising in the form of agreyish column, more than three hundred feet in width at its base, andwhich spread like an immense mushroom to a height of from seven to eighthundred feet above the summit of the mountain.

  "The fire is in the chimney," observed Gideon Spilett.

  "And we can't put it out!" replied Herbert.

  "The volcano ought to be swept," observed Neb, who spoke as if perfectlyserious.

  "Well said, Neb!" cried Pencroft, with a shout of laughter; "and you'llundertake the job, no doubt?"

  Cyrus Harding attentively observed the dense smoke emitted by MountFranklin, and even listened, as if expecting to hear some distantmuttering. Then, turning towards his companions, from whom he had gonesomewhat apart, he said--

  "The truth is, my friends, we must not conceal from ourselves that animportant change is going forward. The volcanic substances are nolonger in a state of ebullition, they have caught fire, and we areundoubtedly menaced by an approaching eruption."

  "Well, captain," said Pencroft, "we shall witness the eruption; and ifit is a good one, we'll applaud it. I don't see that we need concernourselves further about the matter."

  "It may be so," replied Cyrus Harding, "for the ancient track of thelava is still open; and thanks to this, the crater has hithertooverflowed towards the north. And yet--"

  "And yet, as we can derive no advantage from an eruption, it might bebetter it should not take place," said the reporter.

  "Who knows?" answered the sailor. "Perhaps there may be some valuablesubstance in this volcano, which it will spout forth, and which we mayturn to good account!"

  Cyrus Harding shook his head with the air of a man who augured no goodfrom the phenomenon whose developments had been so sudden. He did notregard so lightly as Pencroft the results of an eruption. If the lava,in consequence of the position of the crater, did not directly menacethe wooded and cultivated parts of the island, other complications mightpresent themselves. In fact, eruptions are not unfrequently acco
mpaniedby earthquakes; and an island of the nature of Lincoln Island formed ofsubstances so varied, basalt on one side, granite on the other, lava onthe north, rich soil on the south, substances which consequently couldnot be firmly attached to each other, would be exposed to the risk ofdisintegration. Although, therefore, the spreading of the volcanicmatter might not constitute a serious danger, any movement of theterrestrial structure which should shake the island might entail thegravest consequences.

  "It seems to me," said Ayrton, who had reclined so as to place his earto the ground, "it seems to me that I can hear a dull, rumbling sound,like that of a wagon loaded with bars of iron."

  The colonists listened with the greatest attention, and were convincedthat Ayrton was not mistaken. The rumbling was mingled with asubterranean roar, which formed a sort of _rinforzando_, and died slowlyaway, as if some violent storm had passed through the profundities ofthe globe. But no explosion, properly so termed, could be heard. Itmight therefore be concluded that the vapours and smoke found a freepassage through the central shaft; and that the safety-valve beingsufficiently large, no convulsion would be produced, no explosion was tobe apprehended.

  "Well, then!" said Pencroft, "are we not going back to work? Let MountFranklin smoke, groan, bellow, or spout forth fire and flame as much asit pleases, that is no reason why we should be idle! Come, Ayrton, Neb,Herbert, Captain Harding, Mr Spilett, every one of us must turn to atour work to-day! We are going to place the keelson, and a dozen pair ofhands would not be too many. Before two months I want our new_Bonadventure_--for we shall keep the old name, shall we not?--to floaton the waters of Port Balloon! Therefore there is not an hour to lose!"

  All the colonists, their services thus requisitioned by Pencroft,descended to the dockyard, and proceeded to place the keelson, a thickmass of wood which forms the lower portion of a ship and unites firmlythe timbers of the hull. It was an arduous undertaking, in which alltook part.

  They continued their labours during the whole of this day, the 3rd ofJanuary, without thinking further of the volcano, which could not,besides, be seen from the shore of Granite House. But once or twice,large shadows, veiling the sun, which described its diurnal arc throughan extremely clear sky, indicated that a thick cloud of smoke passedbetween its disc and the island. The wind, blowing on the shore,carried all these vapours to the westward. Cyrus Harding and GideonSpilett remarked these sombre appearances, and from time to timediscussed the evident progress of the volcanic phenomena, but their workwent on without interruption. It was, besides, of the first importancefrom every point of view, that the vessel should be finished with theleast possible delay. In presence of the eventualities which mightarise, the safety of the colonists would be to a great extent secured bytheir ship. Who could tell that it might not prove some day their onlyrefuge?

  In the evening, after supper, Cyrus Harding, Gideon Spilett, andHerbert, again ascended the plateau of Prospect Heights. It was alreadydark, and the obscurity would permit them to ascertain if flames orincandescent matter thrown up by the volcano were mingled with thevapour and smoke accumulated at the mouth of the crater.

  "The crater is on fire!" said Herbert, who, more active than hiscompanions, first reached the plateau.

  Mount Franklin, distant about six miles, now appeared like a gigantictorch, around the summit of which turned fuliginous flames. So muchsmoke, and possibly scoriae and cinders were mingled with them, thattheir light gleamed but faintly amid the gloom of the night. But a kindof lurid brilliancy spread over the island, against which stood outconfusedly the wooded masses of the heights. Immense whirlwinds ofvapour obscured the sky, through which glimmered a few stars.

  "The change is rapid!" said the engineer. "That is not surprising,"answered the reporter. "The re-awakening of the volcano already datesback some time. You may remember, Cyrus, that the first vapoursappeared about the time we searched the sides of the mountain todiscover Captain Nemo's retreat. It was, if I mistake not, about the15th of October."

  "Yes," replied Herbert, "two months and a half ago!"

  "The subterranean fires have therefore been smouldering for ten weeks,"resumed Gideon Spilett, "and it is not to be wondered at that they nowbreak out with such violence!"

  "Do not you feel a certain vibration of the soil?" asked Cyrus Harding.

  "Yes," replied Gideon Spilett, "but there is a great difference betweenthat and an earthquake."

  "I do not affirm that we are menaced with an earthquake," answered CyrusHarding, "may God preserve us from that! No; these vibrations are dueto the effervescence of the central fire. The crust of the earth issimply the shell of a boiler, and you know that such a shell, under thepressure of steam, vibrates like a sonorous plate. It is this effectwhich is being produced at this moment."

  "What magnificent flames!" exclaimed Herbert.

  At this instant a kind of bouquet of flames shot forth from the crater,the brilliancy of which was visible even through the vapours. Thousandsof luminous sheets and barbed tongues of fire were cast in variousdirections. Some, extending beyond the dome of smoke, dissipated it,leaving behind an incandescent powder. This was accompanied bysuccessive explosions, resembling the discharge of a battery ofmitrailleuses.

  Cyrus Harding, the reporter, and Herbert, after spending an hour on theplateau of Prospect Heights, again descended to the beach, and returnedto Granite House. The engineer was thoughtful and preoccupied, so muchso, indeed, that Gideon Spilett inquired if he apprehended any immediatedanger, of which the eruption might directly or indirectly be the cause.

  "Yes, and no," answered Cyrus Harding.

  "Nevertheless," continued the reporter, "would not the greatestmisfortune which could happen to us be an earthquake which wouldoverturn the island? Now, I do not suppose that this is to be feared,since the vapours and lava have found a free outlet."

  "True," replied Cyrus Harding, "and I do not fear an earthquake in thesense in which the term is commonly applied to convulsions of the soilprovoked by the expansion of subterranean gases. But other causes mayproduce great disasters."

  "How so, my dear Cyrus?"

  "I am not certain. I must consider. I must visit the mountain. In afew days I shall learn more on this point."

  Gideon Spilett said no more, and soon, in spite of the explosions of thevolcano, whose intensity increased, and which were repeated by theechoes of the island, the inhabitants of Granite House were sleepingsoundly.

  Three days passed by--the 4th, 5th, and 6th of January. Theconstruction of the vessel was diligently continued, and withoutoffering further explanations the engineer pushed forward the work withall his energy. Mount Franklin was now hooded by a sombre cloud ofsinister aspect, and, amid the flames, vomited forth incandescent rocks,some of which fell back into the crater itself. This caused Pencroft,who would only look at the matter in the light of a joke, to exclaim--

  "Ah! the giant is playing at cup and ball; he is a conjuror."

  In fact, the substances thrown up fell back again into the abyss, and itdid not seem that the lava, though swollen by the internal pressure, hadyet risen to the orifice of the crater. At any rate, the opening on thenorth-east, which was partly visible, poured out no torrent upon thenorthern slope of the mountain.

  Nevertheless, however pressing was the construction of the vessel, otherduties demanded the presence of the colonists on various portions of theisland. Before everything it was necessary to go to the corral, wherethe flocks of musmons and goats were enclosed, and replenish theprovision of forage for those animals. It was accordingly arranged thatAyrton should proceed thither the next day, the 7th of January; and ashe was sufficient for the task, to which he was accustomed, Pencroft andthe rest were somewhat surprised on hearing the engineer say to Ayrton--

  "As you are going to-morrow to the corral I will accompany you."

  "But, Captain Harding," exclaimed the sailor, "our working days will notbe many, and if you go also we shall be two pair of hands short!"

/>   "We shall return to-morrow," replied Cyrus Harding, "but it is necessarythat I should go to the corral. I must learn how the eruption isprogressing."

  "The eruption! always the eruption!" answered Pencroft, with an air ofdiscontent. "An important thing, truly, this eruption! I troublemyself very little about it."

  Whatever might be the sailor's opinion, the expedition projected by theengineer was settled for the next day. Herbert wished to accompanyCyrus Harding, but he would not vex Pencroft by his absence.

  The next day, at dawn, Cyrus Harding and Ayrton, mounting the cart drawnby two onagas, took the road to the corral and set off at a round trot.

  Above the forest were passing large clouds, to which the crater of MountFranklin incessantly added fuliginous matter. These clouds, whichrolled heavily in the air, were evidently composed of heterogeneoussubstances. It was not alone from the volcano that they derived theirstrange opacity and weight. Scorias, in a state of dust, like powderedpumice-stone, and greyish ashes as small as the finest feculae, wereheld in suspension in the midst of their thick folds. These ashes areso fine that they have been observed in the air for whole months. Afterthe eruption of 1783 in Iceland for upwards of a year the atmosphere wasthus charged with volcanic dust through which the rays of the sun wereonly with difficulty discernible.

  But more often this pulverised matter falls, and this happened on thepresent occasion. Cyrus Harding and Ayrton had scarcely reached thecorral when a sort of black snow like fine gunpowder fell, and instantlychanged the appearance of the soil. Trees, meadows, all disappearedbeneath a covering several inches in depth. But, very fortunately, thewind blew from the north-east, and the greater part of the clouddissolved itself over the sea.

  "This is very singular, Captain Harding," said Ayrton.

  "It is very serious," replied the engineer. "This powderedpumice-stone, all this mineral dust, proves how grave is the convulsiongoing forward in the lower depths of the volcano."

  "But can nothing be done?"

  "Nothing, except to note the progress of the phenomenon. Do you,therefore, Ayrton, occupy yourself with the necessary work at thecorral. In the meantime I will ascend just beyond the source of RedCreek and examine the condition of the mountain upon its northernaspect. Then--"

  "Well, Captain Harding?"

  "Then we will pay a visit to Dakkar Grotto. I wish to inspect it. Atany rate I will come back for you in two hours."

  Ayrton then proceeded to enter the corral, and, while waiting theengineer's return, busied himself with the musmons and goats, whichseemed to feel a certain uneasiness in presence of these first signs ofan eruption.

  Meanwhile Cyrus Harding ascended the crest of the eastern spur, passedRed Creek, and arrived at the spot where he and his companions haddiscovered a sulphureous spring at the time of their first exploration.

  How changed was everything! Instead of a single column of smoke hecounted thirteen, forced through the soil as if violently propelled bysome piston. It was evident that the crust of the earth was subjectedin this part of the globe to a frightful pressure. The atmosphere wassaturated with gases and carbonic acid, mingled with aqueous vapours.Cyrus Harding felt the volcanic tufa with which the plain was strewn,and which were but pulverised cinders hardened into solid blocks bytime, tremble beneath him, but he could discover no traces of freshlava.

  The engineer became more assured of this when he observed all thenorthern part of Mount Franklin. Pillars of smoke and flame escapedfrom the crater; a hail of scorias fell on the ground; but no current oflava burst from the mouth of the volcano, which proved that the volcanicmatter had not yet attained the level of the superior orifice of thecentral shaft.

  "But I would prefer that it were so," said Cyrus Harding to himself."At any rate, I should then know that the lava had followed itsaccustomed track. Who can say that they may not take a new course? Butthe danger does not consist in that! Captain Nemo foresaw it clearly!No, the danger does not lie there!"

  Cyrus Harding advanced towards the enormous causeway whose prolongationenclosed the narrow Shark Gulf. He could now sufficiently examine onthis side the ancient channels of the lava. There was no doubt in hismind that the most recent eruption had occurred at a far-distant epoch.

  He then returned by the same way, listening attentively to thesubterranean mutterings which rolled like long-continued thunder,interrupted by deafening explosions. At nine in the morning he reachedthe corral.

  Ayrton awaited him.

  "The animals are cared for, Captain Harding," said Ayrton.

  "Good, Ayrton."

  "They seem uneasy, Captain Harding."

  "Yes, instinct speaks through them, and instinct is never deceived."

  "Are you ready?"

  "Take a lamp, Ayrton," answered the engineer; "we will start at once."

  Ayrton did as desired. The onagas, unharnessed, roamed in the corral.The gate was secured on the outside, and Cyrus Harding, precedingAyrton, took the narrow path which led westward to the shore.

  The soil they walked upon was choked with the pulverised matter fallenfrom the cloud. No quadruped appeared in the woods. Even the birds hadfled. Sometimes a passing breeze raised the covering of ashes, and thetwo colonists, enveloped in a whirlwind of dust, lost sight of eachother. They were then careful to cover their eyes and mouths withhandkerchiefs, for they ran the risk of being blinded and suffocated.

  It was impossible for Cyrus Harding and Ayrton, with these impediments,to make rapid progress. Moreover, the atmosphere was close, as if theoxygen had been partly burnt up, and had become unfit for respiration.At every hundred paces they were obliged to stop to take breath. It wastherefore past ten o'clock when the engineer and his companion reachedthe crest of the enormous mass of rocks of basalt and porphyry whichcomposed the north-west coast of the island.

  Ayrton and Cyrus Harding commenced the descent of this abrupt declivity,following almost step for step the difficult path which, during thatstormy night, had led them to Dakkar Grotto. In open day the descentwas less perilous, and, besides, the bed of ashes which covered thepolished surface of the rock enabled them to make their footing moresecure.

  The ridge at the end of the shore, about forty feet in height, was soonreached. Cyrus Harding recollected that this elevation gradually slopedtowards the level of the sea. Although the tide was at present low, nobeach could be seen, and the waves, thickened by the volcanic dust, beatupon the basaltic rocks.

  Cyrus Harding and Ayrton found without difficulty the entrance to DakkarGrotto, and paused for a moment at the last rock before it.

  "The iron boat should be there," said the engineer.

  "It is here, Captain Harding," replied Ayrton, drawing towards him thefragile craft, which was protected by the arch of a vault.

  "On board, Ayrton!"

  The two colonists stepped into the boat. A slight undulation of thewaves carried it farther under the low arch of the crypt, and thereAyrton, with the aid of flint and steel, lighted the lamp. He then tookthe oars, and the lamp having been placed in the bow of the boat, sothat its rays fell before them, Cyrus Harding took the helm and steeredthrough the shades of the grotto.

  The _Nautilus_ was there no longer to illuminate the cavern with itselectric light. Possibly it might not yet be extinguished, but no rayescaped from the depths of the abyss in which reposed all that wasmortal of Captain Nemo.

  The light afforded by the lamp, although feeble, nevertheless enabledthe engineer to advance slowly, following the wall of the cavern. Adeathlike silence reigned under the vaulted roof, or at least in theanterior portion, for soon Cyrus Harding distinctly heard the rumblingwhich proceeded from the bowels of the mountain.

  "That comes from the volcano," he said.

  Besides these sounds, the presence of chemical combinations was soonbetrayed by their powerful odour, and the engineer and his companionwere almost suffocated by sulphureous vapours.

  "This is what Captain Nemo feared," murmured Cyr
us Harding, changingcountenance. "We must go to the end, notwithstanding."

  "Forward!" replied Ayrton, bending to his oars and directing the boattowards the head of the cavern.

  Twenty-five minutes after entering the mouth of the grotto the boatreached the extreme end.

  Cyrus Harding then, standing up, cast the light of the lamp upon thewalls of the cavern which separated it from the central shaft of thevolcano. What was the thickness of this wall? It might be ten feet ora hundred feet--it was impossible to say. But the subterranean soundswere too perceptible to allow of the supposition that it was of anygreat thickness.

  The engineer, after having explored the wall at a certain heighthorizontally, fastened the lamp to the end of an oar, and again surveyedthe basaltic wall at a greater elevation.

  There, through scarcely visible clefts and joinings, escaped a pungentvapour, which infected the atmosphere of the cavern. The wall wasbroken by large cracks, some of which extended to within two or threefeet of the water's edge.

  Cyrus Harding thought for a brief space. Then he said in a low voice--

  "Yes! the captain was right! The danger lies there, and a terribledanger!"

  Ayrton said not a word, but, upon a sign from Cyrus Harding, resumed theoars, and half an hour later the engineer and he reached the entrance ofDakkar Grotto.