Part 13

The waters seemed extremely well stocked with fish, and Pencroff promised himself he would make some fishing gear in order to take advantage of them.

It was first necessary to double the sharp northeast point. One might have supposed that the discharge of the waters took place at this spot, for the extremity of the lake almost came flush with the edge of the plateau. But such was not the case, and the colonists continued to explore the shore, which, after a slight curve, descended again parallel to the coast. On this side, the bank was less wooded, but a few clumps of trees, scattered here and there, added to the picturesque quality of the landscape. Lake Grant then appeared in all its extent, and no breath of air rippled the surface of its waters. Top, beating through the brushwood, flushed bands of various birds, which Gédéon Spilett and Harbert greeted with their arrows. One of these volatiles was even adroitly struck by the young boy, and fell amid marshy grasses. Top rushed toward him, and brought back a fine swimming bird, slate-colored, with a short beak, a very developed frontal plate, toes widened by a scalloped border, and wings edged with a white line.

It was a "coot," the size of a large partridge, belonging to that group of macrodactyls which forms the transition between the order of waders and that of palmipeds. Sorry game, on the whole, and of a flavor that must have left something to be desired. But Top would no doubt be less particular than his masters, and it was agreed that the coot should serve for his supper.

The colonists were then following the eastern shore of the lake, and they were not long in reaching the portion already reconnoitered. The engineer was much surprised, for he saw no indication of an outflow of the surplus waters. The reporter and the sailor were talking with him, and he did not hide his astonishment from them. At this moment, Top, who had been very calm until then, gave signs of agitation.

The intelligent animal went back and forth on the bank, stopped suddenly, and looked at the water, one paw raised, as if he had been pointing at some invisible game; then, he barked furiously, questing, so to speak, and fell silent abruptly.

Neither Cyrus Smith nor his companions had at first paid any attention to Top's maneuver; but the dog's barking soon became so frequent that the engineer grew concerned.

"What is it, Top?" he asked.

The dog made several leaps toward his master, showing genuine uneasiness, and dashed again toward the bank. Then, suddenly, he plunged into the lake.

"Here, Top!" cried Cyrus Smith, who did not wish to let his dog venture onto those suspicious waters.

"What is going on down there?" asked Pencroff, examining the surface of the lake.

"Top must have scented some amphibian," replied Harbert.

"An alligator, no doubt?" said the reporter.

"I do not think so," replied Cyrus Smith. "Alligators are only found in regions of lower latitude."

Meanwhile, Top had returned at his master's call, and had regained the bank; but he could not remain at rest; he jumped amid the tall grasses, and, guided by instinct, seemed to follow some invisible being that had slipped under the waters of the lake, skirting the edges. However, the waters were calm, and not a ripple troubled their surface. Several times, the colonists stopped on the bank, and observed attentively. Nothing appeared. There was some mystery there.

The engineer was much intrigued.

"Let us pursue this exploration to the end," said he.

Half an hour later, they had all arrived at the southeast angle of the lake and found themselves again on the plateau of Grand-View. At this point, the examination of the lake's shores was to be considered terminated, and yet the engineer had not been able to discover where and how the discharge of the waters took place.

"And yet this spillway exists," he repeated, "and since it is not external, it must be hollowed out inside the granite mass of the coast!"

"But what importance do you attach to knowing that, my dear Cyrus?" asked Gédéon Spilett.

"A rather great one," replied the engineer, "for if the outflow passes through the mass, it is possible that there may be some cavity there, which it would have been easy to make habitable after diverting the waters."

"But is it not possible, Mr. Cyrus, that the waters drain through the very bottom of the lake," said Harbert, "and go to the sea by an underground conduit?"

"That may indeed be," replied the engineer, "and if that is so, we shall be obliged to build our house ourselves, since nature has not borne the first cost of construction."

The colonists were therefore preparing to cross the plateau to regain the Chimneys, for it was five o'clock in the evening, when Top gave new signs of agitation. He barked with rage, and, before his master could hold him, he plunged a second time into the lake.

All ran toward the bank. The dog was already more than twenty feet out, and Cyrus Smith was calling him back sharply, when an enormous head emerged from the surface of the waters, which did not appear to be deep at this spot.

Harbert immediately recognized the species of amphibian to which this conical head with large eyes belonged, decorated with mustaches of long silky hairs.

"A manatee!" he cried.

It was not a manatee, but a specimen of that species, comprised in the order of cetaceans, which bears the name of "dugong," for its nostrils were open in the upper part of its muzzle.

The enormous animal had hurled itself upon the dog, who vainly tried to avoid it by returning toward the bank. His master could do nothing to save him, and before even the thought had come to Gédéon Spilett or Harbert to arm their bows, Top, seized by the dugong, disappeared under the waters.

Nab, his iron-tipped spear in hand, wished to throw himself to the dog's rescue, determined to attack the formidable animal even in its element.

"No, Nab," said the engineer, restraining his courageous servant.

Meanwhile, a struggle was taking place under the waters, an inexplicable struggle, for, in these conditions, Top obviously could not resist; a struggle that must be terrible, as could be seen from the boiling of the surface; a struggle, in short, that could end only with the dog's death! But suddenly, in the midst of a circle of foam, Top was seen to reappear. Hurled into the air by some unknown force, he rose ten feet above the surface of the lake, fell back into the deeply troubled waters, and soon regained the bank without serious wounds, miraculously saved.

Cyrus Smith and his companions looked on without understanding. No less inexplicable circumstance still! It would have seemed that the struggle continued under the waters. No doubt the dugong, attacked by some powerful animal, after releasing the dog, was fighting for its own sake.

But that did not last long. The waters reddened with blood, and the body of the dugong, emerging from a scarlet sheet that spread widely, soon ran aground on a small shore at the south angle of the lake.

The colonists ran toward this spot. The dugong was dead. It was an enormous animal, fifteen to sixteen feet long, which must have weighed three to four thousand pounds. At its neck opened a wound that seemed to have been made with a cutting blade. What then was this amphibian that had, by this terrible blow, destroyed the formidable dugong? No one could have said, and, rather preoccupied by this incident, Cyrus Smith and his companions returned to the Chimneys.

CHAPTER XVII

The next day, May 7, Cyrus Smith and Gédéon Spilett, leaving Nab to prepare breakfast, climbed the plateau of Grand-View, while Harbert and Pencroff went up the river, in order to renew the supply of wood.

The engineer and the reporter soon arrived at that small shore, situated at the south point of the lake, on which the amphibian had remained stranded. Already bands of birds had descended upon this fleshy mass, and it was necessary to drive them off with stones, for Cyrus Smith wished to preserve the dugong's fat and use it for the needs of the colony.

As for the animal's flesh, it could not fail to provide excellent food, since, in certain regions of Malaysia, it is specially reserved for the table of native princes. But that was Nab's affair. At this moment, Cyrus Smith had other thoughts in his head. The incident of the previous day had not been erased from his mind and did not cease to preoccupy him. He would have liked to pierce the mystery of that underwater combat, and to know what congener of mastodons or other sea monsters had given the dugong so strange a wound.

He was therefore there, on the edge of the lake, looking, observing, but nothing appeared under the tranquil waters, which sparkled in the first rays of the sun. On that small shore which supported the dugong's body, the waters were shallow; but, from that point, the bottom of the lake gradually lowered, and it was probable that at the center the depth must be considerable. The lake could be considered as a wide basin, which had been filled by the waters of Red Creek.

"Well, Cyrus," asked the reporter, "it seems to me that these waters offer nothing suspicious?"

"No, my dear Spilett," replied the engineer, "and I truly do not know how to explain yesterday's incident!"

"I confess," resumed Gédéon Spilett, "that the wound made to this amphibian is at least strange, and I could no more explain how it came about that Top was so vigorously thrown out of the waters? One would really believe that it is a powerful arm that launched him thus, and that this same arm, armed with a dagger, then gave death to the dugong!"

"Yes," replied the engineer, who had become pensive. "There is something there that I cannot understand. But do you understand any better, my dear Spilett, in what manner I myself was saved, how I could be snatched from the waves and transported to the dunes? No, is it not so? Hence I foresee some mystery that we shall doubtless discover one day. Let us observe, then, but let us not insist before our companions on these singular incidents. Let us keep our remarks to ourselves and continue our work."

As is known, the engineer had not yet been able to discover where the surplus of the lake escaped, but as he had seen no indication that it ever overflowed, it was necessarily the case that a spillway existed somewhere. Now, precisely, Cyrus Smith was rather surprised to distinguish a fairly pronounced current that made itself felt at this spot. He threw some small pieces of wood, and saw that they directed themselves toward the south angle. He followed this current, walking on the bank, and arrived at the southern point of the lake.

There was produced a sort of depression of the waters, as if they had suddenly been lost in some fissure of the soil.

Cyrus Smith listened, putting his ear level with the lake, and he very distinctly heard the noise of an underground fall.

"It is there," said he, rising, "there that the discharge of the waters takes place, there, no doubt, that by a conduit hollowed in the granite mass they go to rejoin the sea, through some cavities that we should know how to turn to our profit! Well! I shall know it!"

The engineer cut a long branch, stripped it of its leaves, and, plunging it at the angle of the two shores, he ascertained that there existed a wide hole opened at only one foot below the surface of the waters. This hole was the orifice of the spillway so long sought 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 longer any doubt now," repeated Cyrus Smith. "There is the orifice of the spillway, and this orifice, I shall lay it bare."

"How?" asked Gédéon Spilett.

"By lowering the level of the lake's waters by three feet."

"And how lower their level?"

"By opening them another outlet vaster than this one."

"In what place, Cyrus?"

"On the part of the shore that comes nearest to the coast."

"But that is a shore of granite!" observed the reporter.

"Well," replied Cyrus Smith, "I shall blow up that granite, and the waters, in escaping, will lower so as to uncover this orifice..."

"And will form a fall in dropping onto the beach," added the reporter.

"A fall that we shall utilize!" replied the engineer. "Come, come!"

The engineer drew his companion along, whose confidence in Cyrus Smith was such that he did not doubt the enterprise would succeed. And yet, this granite shore, how to open it, how, without powder and with imperfect instruments, to disintegrate those rocks? Was it not a work beyond his strength, to which the engineer was going to furiously devote himself?

When Cyrus Smith and the reporter returned to the Chimneys, they found there Harbert and Pencroff occupied in unloading their train of wood.

"The woodcutters will soon be done, Mr. Cyrus," said the sailor, laughing, "and when you need 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 Pencroff.

"In part, at least!" replied Gédéon 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 that supported the plateau of Grand-View, and he claimed to penetrate to it.

To do this, it was first necessary to clear the opening through which the waters precipitated themselves, and, consequently, to lower their level by procuring them a wider outlet. Hence, the necessity of manufacturing an explosive substance that could make a strong cut at another point of the shore. This is what Cyrus Smith was going to attempt by means of the minerals that nature placed at his disposal.

Needless to say with what enthusiasm all, and more particularly Pencroff, welcomed this project.

To employ the great means, to disembowel this granite, to create a waterfall, that suited the sailor! And he would be as good a chemist as mason or shoemaker, since the engineer needed chemists. He would be whatever one wished, "even professor of dancing and deportment," he said to Nab, if that were ever necessary.

Nab and Pencroff were first charged with extracting the dugong's fat, and preserving its flesh, which was destined for food. They departed at once, without even asking further explanation. The confidence they had in the engineer was absolute. A few moments after them, Cyrus Smith, Harbert and Gédéon Spilett, dragging the hurdle and going up the river, directed themselves toward the coal bed where abounded those schistous pyrites which are in fact found in the most recent transition terrains, and of which Cyrus Smith had already brought back a sample.

The whole day was employed in carrying a certain quantity of these pyrites to the Chimneys. In the evening, there were several tons of them.

The next day, May 8, the engineer began his manipulations. These schistous pyrites being composed principally of coal, silica, alumina and iron sulfide, — the latter in excess, — it was a matter of isolating the iron sulfide and transforming it into sulfate as rapidly as possible. The sulfate obtained, one would extract sulfuric acid from it.

It was indeed the goal to attain. Sulfuric acid is one of the most employed agents, and the industrial importance of a nation can be measured by the consumption that is made of it. This acid would later be of extreme utility to the colonists for the manufacture of candles, the tanning of hides, etc., but at this moment the engineer reserved it for another use.

Cyrus Smith chose, behind the Chimneys, a location whose ground was carefully leveled. On this ground, he placed a pile of branches and chopped wood, on which were placed pieces of pyritous schist, propped one against another; then, the whole was covered with a thin layer of pyrites, previously reduced to the size of a walnut.

This done, fire was set to the wood, whose heat communicated itself to the schists, which caught fire, since they contained coal and sulfur.

Then, new layers of crushed pyrites were arranged so as to form an enormous pile, which was externally lined with earth and grasses, after some vents had been provided, as if it had been a matter of carbonizing a woodpile to make charcoal.

Then, the transformation was left to accomplish itself, and it required no less than ten to twelve days for the iron sulfide to be changed into iron sulfate and the alumina into aluminum sulfate, two equally soluble substances, the others, silica, burnt coal and ashes, not being so.

While this chemical work was accomplishing, Cyrus Smith had other operations proceeded with. More than zeal was put into them. It was fierceness.

Nab and Pencroff had removed the dugong's fat, which had been collected in large earthen jars. This fat, it was a matter of isolating one of its elements, glycerin, by saponifying it. Now, to obtain this result, it sufficed to treat it with soda or lime. Indeed, one or the other of these substances, after attacking the fat, would form a soap while isolating the glycerin, and it was this glycerin that the engineer precisely wished to obtain. Lime was not lacking to him, as is known; only treatment by lime should give only calcareous soaps, insoluble and consequently useless, while treatment by soda would, on the contrary, furnish a soluble soap, which would find its employment in domestic cleanings.

Now, as a practical man, Cyrus Smith should rather seek to obtain soda. Was it difficult?

No, for marine plants abounded on the shore, glassworts, fig-marigolds, and all those fucaceae that form wracks and kelp. A great quantity of these plants was therefore gathered, they were first dried, then afterward burned in pits in the open air. The combustion of these plants was maintained for several days, so that the heat rose to the point of melting their ashes, and the result of the incineration was a compact, grayish mass, long known under the name of "natural soda."

This result obtained, the engineer treated the fat with soda, which gave, on one hand, a soluble soap, and, on the other, that neutral substance, glycerin.

But that was not all. Cyrus Smith still needed, with a view to his future preparation, another substance, nitrate of potash, which is better known under the name of nitrite salt or saltpeter.

Cyrus Smith could have manufactured this substance, by treating carbonate of potash, which is easily extracted from the ashes of vegetables, with nitric acid. But nitric acid was lacking to him, and it was precisely this acid that he wished to obtain, in the final account. There was therefore there a vicious circle, from which he would never have emerged.

Very happily, this time, nature was going to furnish him saltpeter, without his having any other trouble than to gather it. Harbert discovered a bed of it in the north of the island, at the foot of Mount Franklin, and there was nothing left but to purify this salt.

These diverse works lasted about a week. They were therefore completed, before the transformation of the sulfide into iron sulfate had been accomplished. During the days that followed, the colonists had time to manufacture refractory pottery of plastic clay and to construct a brick furnace of a particular disposition which was to serve for the distillation of the iron sulfate, when that should be obtained. All that was finished toward May 18, almost at the moment when the chemical transformation was terminating. Gédéon Spilett, Harbert, Nab and Pencroff, ably guided by the engineer, had become the most skillful workmen in the world. Necessity is, moreover, of all masters, the one most listened to and who teaches best.

When the pile of pyrites had been entirely reduced by fire, the result of the operation, consisting of iron sulfate, aluminum sulfate, silica, residue of coal and ashes, was deposited in a basin filled with water. This mixture was stirred, left to settle, then decanted, and a clear liquid was obtained, containing in solution iron sulfate and aluminum sulfate, the other matters having remained solid, since they were insoluble. Finally, this liquid having partly vaporized, crystals of iron sulfate deposited, and the mother liquors, that is to say the non-vaporized liquid which contained aluminum sulfate, were abandoned.

Cyrus Smith therefore had at his disposal a rather great quantity of these crystals of iron sulfate, from which it was a matter of extracting sulfuric acid.

In industrial practice, it is a costly installation that the manufacture of sulfuric acid requires. It is necessary, indeed, considerable factories, special tooling, platinum apparatus, lead chambers, unattackable by the acid, and in which the transformation operates, etc. The engineer had not this equipment at his disposal, but he knew that in Bohemia particularly, sulfuric acid is manufactured by simpler means, which have even the advantage of producing it at a superior degree of concentration.

It is thus that the acid known under the name of Nordhausen acid is made.

To obtain sulfuric acid, Cyrus Smith had only one operation left to do: to calcine in a closed vessel the crystals of iron sulfate, so that the sulfuric acid should distill in vapors, which vapors would afterward produce the acid by condensation.

It was for this manipulation that the refractory potteries served, in which the crystals were placed, and the furnace, whose heat was to distill the sulfuric acid. The operation was perfectly conducted, and on May 20, twelve days after having begun, the engineer was possessor of the agent that he counted on utilizing later in so many different ways.

Now, why did he wish to have this agent? Simply to produce nitric acid, and that was easy, since the saltpeter, attacked by sulfuric acid, gave him precisely this acid by distillation.

But, in the final account, to what was he going to employ this nitric acid? That is what his companions still ignored, for he had not said the last word of his work.

However, the engineer was touching his goal, and a final operation procured him the substance that had required so many manipulations.

After taking some nitric acid, he put it in presence of the glycerin, which had been previously concentrated by evaporation in a bain-marie, and he obtained, even without employing a refrigerating mixture, several pints of an oily and yellowish liquid.

This last operation, Cyrus Smith had done alone, apart, far from the Chimneys, for it presented dangers of explosion, and, when he brought back a flask of this liquid to his friends, he contented himself with telling them: "There is nitro-glycerin!"

It was, indeed, this terrible product, whose explosive power is perhaps tenfold that of ordinary powder, and which has already caused so many accidents! However, since the means has been found to transform it into dynamite, that is to say to mix it with a solid substance, clay or sugar, porous enough to retain it, the dangerous liquid has been able to be utilized with more security. But dynamite was not yet known at the epoch when the colonists were operating in Lincoln Island.

"And it is that liquid there which is going to blow up our rocks?" said Pencroff with a rather incredulous air.

"Yes, my friend," replied the engineer, "and this nitro-glycerin will produce so much the more effect, as this granite is extremely hard and will oppose a greater resistance to bursting."

"And when shall we see that, Mr. Cyrus?"

"Tomorrow, as soon as we have dug a mine hole," replied the engineer.

“Stories of the world, in your language.”