Part 1 - Dropped from the Clouds: Chapter 17

by Jules Verne

　　The next day, the 7th of May, Harding and Gideon Spilett, leaving Neb toprepare breakfast, climbed Prospect Heights, while Herbert and Pencroftascended by the river, to renew their store of wood.

　　The engineer and the reporter soon reached the little beach on which thedugong had been stranded. Already flocks of birds had attacked the mass offlesh, and had to be driven away with stones, for Cyrus wished to keep thefat for the use of the colony. As to the animal's flesh it would furnishexcellent food, for in the islands of the Malay Archipelago and elsewhere,it is especially reserved for the table of the native princes. But that wasNeb's affair.

　　At this moment Cyrus Harding had other thoughts. He was much interestedin the incident of the day before. He wished to penetrate the mystery ofthat submarine combat, and to ascertain what monster could have given thedugong so strange a wound. He remained at the edge of the lake, looking,observing; but nothing appeared under the tranquil waters, which sparkledin the first rays of the rising sun.

　　At the beach, on which lay the body of the dugong, the water wastolerably shallow, but from this point the bottom of the lake slopedgradually, and it was probable that the depth was considerable in thecenter. The lake might be considered as a large center basin, which wasfilled by the water from the Red Creek.

　　"Well, Cyrus," said the reporter, "there seems to be nothing suspiciousin this water."

　　"No, my dear Spilett," replied the engineer, "and I really do not know howto account for the incident of yesterday."

　　"I acknowledge," returned Spilett, "that the wound given this creatureis, at least, very strange, and I cannot explain either how Top was sovigorously cast up out of the water. One could have thought that a powerfularm hurled him up, and that the same arm with a dagger killed the dugong!"

　　"Yes," replied the engineer, who had become thoughtful; "there issomething there that I cannot understand. But do you better understandeither, my dear Spilett, in what way I was saved myself--how I was drawnfrom the waves, and carried to the downs? No! Is it not true? Now, I feelsure that there is some mystery there, which, doubtless, we shall discoversome day. Let us observe, but do not dwell on these singular incidentsbefore our companions. Let us keep our remarks to ourselves, and continueour work."

　　It will be remembered that the engineer had not as yet been able todiscover the place where the surplus water escaped, but he knew it mustexist somewhere. He was much surprised to see a strong current at thisplace. By throwing in some bits of wood he found that it set towards thesouthern angle. He followed the current, and arrived at the south point ofthe lake.

　　There was there a sort of depression in the water, as if it was suddenlylost in some fissure in the ground.

　　Harding listened; placing his ear to the level of the lake, he verydistinctly heard the noise of a subterranean fall.

　　"There," said he, rising, "is the discharge of the water; there,doubtless, by a passage in the granite cliff, it joins the sea, throughcavities which we can use to our profit. Well, I can find it!"

　　The engineer cut a long branch, stripped it of its leaves, and plungingit into the angle between the two banks, he found that there was a largehole one foot only beneath the surface of the water. This hole was theopening so long looked for in vain, and the force of the current was suchthat the branch was torn from the engineer's hands and disappeared.

　　"There is no doubt about it now," repeated Harding. "There is the outlet,and I will lay it open to view!"

　　"How?" asked Gideon Spilett.

　　"By lowering the level of the water of the lake three feet." "And howwill you lower the level?"

　　"By opening another outlet larger than this."

　　"At what place, Cyrus?"

　　"At the part of the bank nearest the coast."

　　"But it is a mass of granite!" observed Spilett.

　　"Well," replied Cyrus Harding, "I will blow up the granite, and the waterescaping, will subside, so as to lay bare this opening--"

　　"And make a waterfall, by falling on to the beach," added the reporter.

　　"A fall that we shall make use of!" replied Cyrus. "Come, come!"

　　The engineer hurried away his companion, whose confidence in Harding wassuch that he did not doubt the enterprise would succeed. And yet, how wasthis granite wall to be opened without powder, and with imperfectinstruments? Was not this work upon which the engineer was so bent abovetheir strength?

　　When Harding and the reporter entered the Chimneys, they found Herbertand Pencroft unloading their raft of wood.

　　"The woodmen have just finished, captain." said the sailor, laughing, "andwhen you want masons--"

　　"Masons,--no, but chemists," replied the engineer.

　　"Yes," added the reporter, "we are going to blow up the island--"

　　"Blow up the island?" cried Pencroft.

　　"Part of it, at least," replied Spilett.

　　"Listen to me, my friends," said the engineer. And he made known to themthe result of his observations.

　　According to him, a cavity, more or less considerable, must exist in themass of granite which supported Prospect Heights, and he intended topenetrate into it. To do this, the opening through which the water rushedmust first be cleared, and the level lowered by making a larger outlet.Therefore an explosive substance must be manufactured, which would make adeep trench in some other part of the shore. This was what Harding wasgoing to attempt with the minerals which nature placed at his disposal.

　　It is useless to say with what enthusiasm all, especially Pencroft,received this project. To employ great means, open the granite, create acascade, that suited the sailor. And he would just as soon be a chemist asa mason or bootmaker, since the engineer wanted chemicals. He would be allthat they liked, "even a professor of dancing and deportment," said he toNeb, if that was ever necessary.

　　Neb and Pencroft were first of all told to extract the grease from thedugong, and to keep the flesh, which was destined for food. Such perfectconfidence had they in the engineer, that they set out directly, withouteven asking a question. A few minutes after them, Cyrus Harding, Herbert,and Gideon Spilett, dragging the hurdle, went towards the vein of coals,where those shistose pyrites abound which are met with in the most recenttransition soil, and of which Harding had already found a specimen. All theday being employed in carrying a quantity of these stones to the Chimneys,by evening they had several tons.

　　The next day, the 8th of May, the engineer began his manipulations. Theseshistose pyrites being composed principally of coal, flint, alumina, andsulphuret of iron--the latter in excess--it was necessary to separate thesulphuret of iron, and transform it into sulphate as rapidly as possible.The sulphate obtained, the sulphuric acid could then be extracted.

　　This was the object to be attained. Sulphuric acid is one of the agentsthe most frequently employed, and the manufacturing importance of a nationcan be measured by the consumption which is made of it. This acid wouldlater be of great use to the settlers, in the manufacturing of candles,tanning skins, etc., but this time the engineer reserved it for anotheruse.

　　Cyrus Harding chose, behind the Chimneys, a site where the ground wasperfectly level. On this ground he placed a layer of branches and choppedwood, on which were piled some pieces of shistose pyrites, buttressed oneagainst the other, the whole being covered with a thin layer of pyrites,previously reduced to the size of a nut.

　　This done, they set fire to the wood, the heat was communicated to theshist, which soon kindled, since it contains coal and sulphur. Then newlayers of bruised pyrites were arranged so as to form an immense heap, theexterior of which was covered with earth and grass, several air-holes beingleft, as if it was a stack of wood which was to be carbonized to makecharcoal.

　　They then left the transformation to complete itself, and it would nottake less than ten or twelve days for the sulphuret of iron to be changedto sulphate of iron and the alumina into sulphate of alumina, two equallysoluble substances, the others, flint, burnt coal, and cinders, not beingso.

　　While this chemical work was going on, Cyrus Harding proceeded with otheroperations, which were pursued with more than zeal,--it was eagerness.

　　Neb and Pencroft had taken away the fat from the dugong, and placed it inlarge earthen pots. It was then necessary to separate the glycerine fromthe fat by saponifying it. Now, to obtain this result, it had to be treatedeither with soda or lime. In fact, one or other of these substances, afterhaving attacked the fat, would form a soap by separating the glycerine, andit was just this glycerine which the engineer wished to obtain. There wasno want of lime, only treatment by lime would give calcareous soap,insoluble, and consequently useless, while treatment by soda would furnish,on the contrary, a soluble soap, which could be put to domestic use. Now, apractical man, like Cyrus Harding, would rather try to obtain soda. Wasthis difficult? No; for marine plants abounded on the shore, glass-wort,ficoides, and all those fucaceae which form wrack. A large quantity ofthese plants was collected, first dried, then burnt in holes in the openair. The combustion of these plants was kept up for several days, and theresult was a compact gray mass, which has been long known under the name of"natural soda."

　　This obtained, the engineer treated the fat with soda, which gave both asoluble soap and that neutral substance, glycerine.

　　But this was not all. Cyrus Harding still needed, in view of his futurepreparation, another substance, nitrate of potash, which is better knownunder the name of salt niter, or of saltpeter.

　　Cyrus Harding could have manufactured this substance by treating thecarbonate of potash, which would be easily extracted from the cinders ofthe vegetables, by azotic acid. But this acid was wanting, and he wouldhave been in some difficulty, if nature had not happily furnished thesaltpeter, without giving them any other trouble than that of picking itup. Herbert found a vein of it at the foot of Mount Franklin, and they hadnothing to do but purify this salt.

　　These different works lasted a week. They were finished before thetransformation of the sulphuret into sulphate of iron had beenaccomplished. During the following days the settlers had time to constructa furnace of bricks of a particular arrangement, to serve for thedistillation of the sulphate or iron when it had been obtained. All thiswas finished about the 18th of May, nearly at the time when the chemicaltransformation terminated. Gideon Spilett, Herbert, Neb, and Pencroft,skillfully directed by the engineer, had become most clever workmen. Beforeall masters, necessity is the one most listened to, and who teaches thebest.

　　When the heap of pyrites had been entirely reduced by fire, the result ofthe operation, consisting of sulphate of iron, sulphate of alumina, flint,remains of coal, and cinders was placed in a basinful of water. Theystirred this mixture, let it settle, then decanted it, and obtained a clearliquid containing in solution sulphate of iron and sulphate of alumina, theother matters remaining solid, since they are insoluble. Lastly, thisliquid being partly evaporated, crystals of sulphate of iron weredeposited, and the not evaporated liquid, which contained the sulphate ofalumina, was thrown away.

　　Cyrus Harding had now at his disposal a large quantity of these sulphateof iron crystals, from which the sulphuric acid had to be extracted. Themaking of sulphuric acid is a very expensive manufacture. Considerableworks are necessary--a special set of tools, an apparatus of platina,leaden chambers, unassailable by the acid, and in which the transformationis performed, etc. The engineer had none of these at his disposal, but heknew that, in Bohemia especially, sulphuric acid is manufactured by verysimple means, which have also the advantage of producing it to a superiordegree of concentration. It is thus that the acid known under the name ofNordhausen acid is made.

　　To obtain sulphuric acid, Cyrus Harding had only one operation to make,to calcine the sulphate of iron crystals in a closed vase, so that thesulphuric acid should distil in vapor, which vapor, by condensation, wouldproduce the acid.

　　The crystals were placed in pots, and the heat from the furnace woulddistil the sulphuric acid. The operation was successfully completed, and onthe 20th of May, twelve days after commencing it, the engineer was thepossessor of the agent which later he hoped to use in so many differentways.

　　Now, why did he wish for this agent? Simply to produce azotic acid; andthat was easy, since saltpeter, attacked by sulphuric acid, gives azotic,or nitric, acid by distillation.

　　But, after all, how was he going to employ this azotic acid? Hiscompanions were still ignorant of this, for he had not informed them of theresult at which he aimed.

　　However, the engineer had nearly accomplished his purpose, and by a lastoperation he would procure the substance which had given so much trouble.

　　Taking some azotic acid, he mixed it with glycerine, which had beenpreviously concentrated by evaporation, subjected to the water-bath, and heobtained, without even employing a refrigerant mixture, several pints of anoily yellow mixture.

　　This last operation Cyrus Harding had made alone, in a retired place, ata distance from the Chimneys, for he feared the danger of an explosion, andwhen he showed a bottle of this liquid to his friends, he contented himselfwith saying,--

　　"Here is nitro-glycerine!"

　　It was really this terrible production, of which the explosive power isperhaps tenfold that of ordinary powder, and which has already caused somany accidents. However, since a way has been found to transform it intodynamite, that is to say, to mix with it some solid substance, clay orsugar, porous enough to hold it, the dangerous liquid has been used withsome security. But dynamite was not yet known at the time when the settlersworked on Lincoln Island.

　　"And is it that liquid that is going to blow up our rocks?" said Pencroftincredulously.

　　"Yes, my friend," replied the engineer, "and this nitro-glycerine willproduce so much the more effect, as the granite is extremely hard, and willoppose a greater resistance to the explosion."

　　"And when shall we see this, captain?"

　　"To-morrow, as soon as we have dug a hole for the mine, replied theengineer.

　　The next day, the 21st of May, at daybreak, the miners went to the pointwhich formed the eastern shore of Lake Grant, and was only five hundredfeet from the coast. At this place, the plateau inclined downwards from thewaters, which were only restrained by their granite case. Therefore, ifthis case was broken, the water would escape by the opening and form astream, which, flowing over the inclined surface of the plateau, would rushon to the beach. Consequently, the level of the lake would be greatlylowered, and the opening where the water escaped would be exposed, whichwas their final aim.

　　Under the engineer's directions, Pencroft, armed with a pickaxe, which hehandled skillfully and vigorously, attacked the granite. The hole was madeon the point of the shore, slanting, so that it should meet a much lowerlevel than that of the water of the lake. In this way the explosive force,by scattering the rock, would open a large place for the water to rush out.

　　The work took some time, for the engineer, wishing to produce a greateffect, intended to devote not less than seven quarts of nitro-glycerine tothe operation. But Pencroft, relieved by Neb, did so well, that towardsfour o'clock in the evening, the mine was finished.

　　Now the question of setting fire to the explosive substance was raised.Generally, nitro-glycerine is ignited by caps of fulminate, which inbursting cause the explosion. A shock is therefore needed to produce theexplosion, for, simply lighted, this substance would burn withoutexploding.

　　Cyrus Harding could certainly have fabricated a percussion cap. Indefault of fulminate, he could easily obtain a substance similar toguncotton, since he had azotic acid at his disposal. This substance,pressed in a cartridge, and introduced among the nitro-glycerine, wouldburst by means of a fuse, and cause the explosion.

　　But Cyrus Harding knew that nitro-glycerine would explode by a shock. Heresolved to employ this means, and try another way, if this did notsucceed.

　　In fact, the blow of a hammer on a few drops of nitro-glycerine, spreadout on a hard surface, was enough to create an explosion. But the operatorcould not be there to give the blow, without becoming a victim to theoperation. Harding, therefore, thought of suspending a mass of iron,weighing several pounds, by means of a fiber, to an upright just above themine. Another long fiber, previously impregnated with sulphur, was attachedto the middle of the first, by one end, while the other lay on the groundseveral feet distant from the mine. The second fiber being set on fire, itwould burn till it reached the first. This catching fire in its turn, wouldbreak, and the mass of iron would fall on the nitro-glycerine. Thisapparatus being then arranged, the engineer, after having sent hiscompanions to a distance, filled the hole, so that the nitro-glycerine wason a level with the opening; then he threw a few drops of it on the surfaceof the rock, above which the mass of iron was already suspended.

　　This done, Harding lit the end of the sulphured fiber, and leaving theplace, he returned with his companions to the Chimneys.

　　The fiber was intended to burn five and twenty minutes, and, in fact,five and twenty minutes afterwards a most tremendous explosion was heard.The island appeared to tremble to its very foundation. Stones wereprojected in the air as if by the eruption of a volcano. The shock producedby the displacing of the air was such, that the rocks of the Chimneysshook. The settlers, although they were more than two miles from the mine,were thrown on the ground.

　　They rose, climbed the plateau, and ran towards the place where the bankof the lake must have been shattered by the explosion.

　　A cheer escaped them! A large rent was seen in the granite! A rapidstream of water rushed foaming across the plateau and dashed down a heightof three hundred feet on to the beach!