Île mystérieuse. English

Chapter 17

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

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

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

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

“Well, Cyrus,” said the re­porter, “there seems to be noth­ing sus­pi­cious in this wa­ter.”

“No, my dear Spilett,” replied the en­gi­neer, “and I re­al­ly do not know how to ac­count for the in­ci­dent of yes­ter­day.”

“I ac­knowl­edge,” re­turned Spilett, “that the wound giv­en this crea­ture is, at least, very strange, and I can­not ex­plain ei­ther how Top was so vig­or­ous­ly cast up out of the wa­ter. One could have thought that a pow­er­ful arm hurled him up, and that the same arm with a dag­ger killed the dugong!”

“Yes,” replied the en­gi­neer, who had be­come thought­ful; “there is some­thing there that I can­not un­der­stand. But do you bet­ter un­der­stand ei­ther, my dear Spilett, in what way I was saved my­self–how I was drawn from the waves, and car­ried to the downs? No! Is it not true? Now, I feel sure that there is some mys­tery there, which, doubt­less, we shall dis­cov­er some day. Let us ob­serve, but do not dwell on these sin­gu­lar in­ci­dents be­fore our com­pan­ions. Let us keep our re­marks to our­selves, and con­tin­ue our work.”

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

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

Hard­ing lis­tened; plac­ing his ear to the lev­el of the lake, he very dis­tinct­ly 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, through cav­ities which we can use to our prof­it. Well, I can find it!”

The en­gi­neer cut a long branch, stripped it of its leaves, and plung­ing it in­to the an­gle be­tween the two banks, he found that there was a large hole one foot on­ly be­neath the sur­face of the wa­ter. This hole was the open­ing so long looked for in vain, and the force of the cur­rent was such that 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 how will 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 wa­ter es­cap­ing, 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 was such that he did not doubt the en­ter­prise would suc­ceed. And yet, how was this gran­ite wall to be opened with­out pow­der, and with im­per­fect in­stru­ments? Was not this work up­on which the en­gi­neer was so bent above their strength?

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

“The wood­men have just fin­ished, cap­tain.” said the sailor, laugh­ing, “and when 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 them the re­sult of his ob­ser­va­tions.

Ac­cord­ing to him, a cav­ity, more or less con­sid­er­able, must ex­ist in the mass of gran­ite which sup­port­ed Prospect Heights, and he in­tend­ed to pen­etrate in­to it. To do this, the open­ing through which the wa­ter rushed must first be cleared, and the lev­el low­ered by mak­ing a larg­er out­let. There­fore an ex­plo­sive sub­stance must be man­ufac­tured, which would make a deep trench in some oth­er part of the shore. This was what Hard­ing was go­ing 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 a cas­cade, that suit­ed the sailor. And he would just as soon be a chemist as a ma­son or boot­mak­er, since the en­gi­neer want­ed chem­icals. He would be all that they liked, “even a pro­fes­sor of danc­ing and de­port­ment,” said he to Neb, if that was ev­er nec­es­sary.

Neb and Pen­croft were first of all told to ex­tract the grease from the dugong, and to keep the flesh, which was des­tined for food. Such per­fect con­fi­dence had they in the en­gi­neer, that they set out di­rect­ly, with­out even 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 re­cent tran­si­tion soil, and of which Hard­ing had al­ready found a spec­imen. All the day 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. These shis­tose pyrites be­ing com­posed prin­ci­pal­ly of coal, flint, alu­mi­na, and sul­phuret of iron–the lat­ter in ex­cess–it was nec­es­sary to sep­arate the sul­phuret 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 agents the most fre­quent­ly em­ployed, and the man­ufac­tur­ing im­por­tance of a na­tion can be mea­sured by the con­sump­tion which is made of it. This acid would lat­er be of great use to the set­tlers, in the man­ufac­tur­ing of can­dles, tan­ning skins, etc., but this time the en­gi­neer re­served it for an­oth­er use.

Cyrus Hard­ing chose, be­hind the Chim­neys, a site where the ground was per­fect­ly lev­el. On this ground he placed a lay­er of branch­es and chopped wood, on which were piled some pieces of shis­tose pyrites, but­tressed one against 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 the shist, which soon kin­dled, since it con­tains coal and sul­phur. Then new lay­ers of bruised pyrites were ar­ranged so as to form an im­mense heap, the ex­te­ri­or of which was cov­ered with earth and grass, sev­er­al air-​holes be­ing left, as if it was a stack of wood which was to be car­bonized to make char­coal.

They then left the trans­for­ma­tion to com­plete it­self, and it would not take less than ten or twelve days for the sul­phuret of iron to be changed to sul­phate of iron and the alu­mi­na in­to sul­phate of alu­mi­na, two equal­ly sol­uble sub­stances, the oth­ers, flint, burnt coal, and cin­ders, not be­ing so.

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

Neb and Pen­croft had tak­en away the fat from the dugong, and placed it in large earth­en pots. It was then nec­es­sary to sep­arate the glyc­er­ine from the fat by saponi­fy­ing it. Now, to ob­tain this re­sult, it had to be treat­ed ei­ther with so­da or lime. In fact, one or oth­er of these sub­stances, af­ter hav­ing at­tacked the fat, would form a soap by sep­arat­ing the glyc­er­ine, and it was just this glyc­er­ine which the en­gi­neer wished to ob­tain. There was no 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, a prac­ti­cal man, like Cyrus Hard­ing, would rather try to ob­tain so­da. Was this dif­fi­cult? No; for ma­rine plants abound­ed on the shore, glass-​wort, fi­coides, and all those fu­caceae which form wrack. A large quan­ti­ty of these plants was col­lect­ed, first dried, then burnt in holes in the open air. The com­bus­tion of these plants was kept up for sev­er­al days, and the re­sult 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 a sol­uble soap and that neu­tral sub­stance, glyc­er­ine.

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

Cyrus Hard­ing could have man­ufac­tured this sub­stance by treat­ing the car­bon­ate of potash, which would be eas­ily ex­tract­ed from the cin­ders of the veg­eta­bles, by azot­ic acid. But this acid was want­ing, and he would have been in some dif­fi­cul­ty, if na­ture had not hap­pi­ly fur­nished the salt­peter, with­out giv­ing them any oth­er trou­ble than that of pick­ing it up. Her­bert found a vein of it at the foot of Mount Franklin, and they had noth­ing to do but pu­ri­fy this salt.

These dif­fer­ent works last­ed a week. They were fin­ished be­fore the trans­for­ma­tion of the sul­phuret in­to sul­phate of iron had been ac­com­plished. Dur­ing the fol­low­ing days the set­tlers had time to con­struct a fur­nace of bricks of a par­tic­ular ar­range­ment, to serve for the dis­til­la­tion of the sul­phate or iron when it had been ob­tained. All this was fin­ished about the 18th of May, near­ly at the time when the chem­ical trans­for­ma­tion ter­mi­nat­ed. Gideon Spilett, Her­bert, Neb, and Pen­croft, skill­ful­ly di­rect­ed by the en­gi­neer, had be­come most clever work­men. Be­fore all mas­ters, ne­ces­si­ty is the one most lis­tened to, and who teach­es the best.

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

Cyrus Hard­ing had now at his dis­pos­al a large quan­ti­ty of these sul­phate of iron crys­tals, from which the sul­phuric acid had to be ex­tract­ed. The mak­ing of sul­phuric acid is a very ex­pen­sive man­ufac­ture. Con­sid­er­able works are nec­es­sary–a spe­cial set of tools, an ap­pa­ra­tus of plati­na, lead­en cham­bers, unas­sail­able by the acid, and in which the trans­for­ma­tion is per­formed, etc. The en­gi­neer had none of these at his dis­pos­al, but he knew that, in Bo­hemia es­pe­cial­ly, sul­phuric acid is man­ufac­tured by very sim­ple means, which have al­so the ad­van­tage of pro­duc­ing it to a su­pe­ri­or de­gree of con­cen­tra­tion. It is thus that the acid known un­der the name of Nord­hausen 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 the sul­phuric acid should dis­til in va­por, which va­por, by con­den­sa­tion, would pro­duce the acid.

The crys­tals were placed in pots, and the heat from the fur­nace would dis­til the sul­phuric acid. The op­er­ation was suc­cess­ful­ly com­plet­ed, and on the 20th of May, twelve days af­ter com­menc­ing it, the en­gi­neer was the pos­ses­sor of the agent which lat­er he hoped to use in so many dif­fer­ent ways.

Now, why did he wish for this agent? Sim­ply to pro­duce azot­ic acid; and that 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? His com­pan­ions were still ig­no­rant of this, for he had not in­formed them of the re­sult at which he aimed.

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

Tak­ing some azot­ic acid, he mixed it with glyc­er­ine, which had been pre­vi­ous­ly con­cen­trat­ed by evap­ora­tion, sub­ject­ed to the wa­ter-​bath, and he ob­tained, with­out even em­ploy­ing a re­frig­er­ant mix­ture, sev­er­al pints of an oily yel­low mix­ture.

This last op­er­ation Cyrus Hard­ing had made alone, in a re­tired place, at a dis­tance from the Chim­neys, for he feared the dan­ger of an ex­plo­sion, and when he showed a bot­tle of this liq­uid to his friends, he con­tent­ed him­self with say­ing,–

“Here is ni­tro-​glyc­er­ine!”

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

“And is it that liq­uid that is go­ing to blow up our rocks?” said Pen­croft in­cred­ulous­ly.

“Yes, my friend,” replied the en­gi­neer, “and this ni­tro-​glyc­er­ine will pro­duce so much the more ef­fect, as the gran­ite is ex­treme­ly hard, and will op­pose 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 the en­gi­neer.”

The next day, the 21st of May, at day­break, the min­ers went to the point which formed the east­ern shore of Lake Grant, and was on­ly five hun­dred feet from the coast. At this place, the plateau in­clined down­wards from the wa­ters, which were on­ly re­strained by their gran­ite case. There­fore, if this case was bro­ken, the wa­ter would es­cape by the open­ing and form a stream, which, flow­ing over the in­clined sur­face of the plateau, would rush on to the beach. Con­se­quent­ly, the lev­el of the lake would be great­ly low­ered, and the open­ing where the wa­ter es­caped would be ex­posed, which was their fi­nal aim.

Un­der the en­gi­neer’s di­rec­tions, Pen­croft, armed with a pick­axe, which he han­dled skill­ful­ly and vig­or­ous­ly, at­tacked the gran­ite. The hole was made on the point of the shore, slant­ing, so that it should meet a much low­er lev­el 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 great ef­fect, in­tend­ed to de­vote not less than sev­en quarts of ni­tro-​glyc­er­ine to the op­er­ation. But Pen­croft, re­lieved by Neb, did so well, that to­wards four 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 in burst­ing cause the ex­plo­sion. A shock is there­fore need­ed to pro­duce the ex­plo­sion, for, sim­ply light­ed, this sub­stance would burn with­out ex­plod­ing.

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

But Cyrus Hard­ing knew that ni­tro-​glyc­er­ine would ex­plode by a shock. He re­solved to em­ploy this means, and try an­oth­er way, if this did not suc­ceed.

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

This done, Hard­ing lit the end of the sul­phured fiber, and leav­ing the place, 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 were pro­ject­ed in the air as if by the erup­tion of a vol­cano. The shock pro­duced by the dis­plac­ing of the air was such, that the rocks of the Chim­neys shook. 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 bank of the lake must have been shat­tered by the ex­plo­sion.

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