“This is nitroglycerin.”
The next day, the 7th of May, Cyrus Smith and Gideon Spilett, leaving Neb to prepare breakfast, climbed to Grand View Plateau, while Herbert and Pencroff went up the river in order to renew the provision of wood.
The engineer and the reporter soon arrived at this small beach situated at the southern point of the lake where the amphibian was stranded. Already flocks of birds were attacking the mass of flesh and it was necessary to drive them away with stones because Cyrus Smith wanted to save the fat from the dugong and use it for the needs of the colony. As to the flesh of the animal, it would not fail to furnish excellent nourishment. In certain Malay regions, it is especially reserved for the tables of the native princes. But that was Neb’s affair.
At the moment Cyrus Smith had other thoughts in mind. He had not forgotten the previous day’s incident nor had he stopped thinking about it. He wished to pierce the mystery of this underwater combat and to know what kind of mastodon or other marine monster had given the dugong so strange a wound.
He was there at the edge of the lake, looking and observing, but nothing appeared under the tranquil waters which were glistening under the first rays of the sun.
Near this small beach which held the dugong’s body, the water was not very deep; but on leaving this point the bottom of the lake fell little by little and it was probable that at the center the depth was considerable. The lake could be considered as a large basin which was replenished by the water from Red Creek.
“Well then, Cyrus,” said the reporter, “it seems to me that these waters do not offer anything suspicious.”
“No, my dear Spilett,” replied the engineer, “and I really do not know how to explain yesterday’s incident.”
“I acknowledge,” replied Gideon Spilett, “that the wound given to this amphibian is strange, to say the least, and neither can I explain how Top was so vigorously thrown out of the water. One could really believe that it was a powerful arm that had thrown him in this way and that this same arm had then killed the dugong with a dagger.”
“Yes,” said the engineer, who became thoughtful. “There is something here that I cannot comprehend. But can you either understand, my dear Spilett, in what way I myself was saved, how I was able to pull myself from the waves and cross the dunes? No, isn’t it true? I have a presentiment of some mystery here which we will doubtless discover one day. Let us therefore observe but not dwell on these singular incidents in front of our companions. Let us keep our remarks to ourselves and continue our work.”
As we know, the engineer still had not been able to discover where the overflow of the lake escaped, but although he had never seen any indication that it overflowed, still it was necessary that an opening exist somewhere. Cyrus Smith was now rather surprised to perceive a rather pronounced current which made itself felt at this point. He threw in some small pieces of wood and they rapidly went toward the southern corner. Walking along the bank, he followed this current and he arrived at the southern point of the lake.
A sort of depression was produced in the water there, as if it was abruptly lost in some fissure in the ground.
Cyrus Smith listened, placing his ear at the level of the lake, and he very distinctly heard the noise of a subterranean falls.
“It is there,” he said, getting up, “there that the water discharges, there doubtless by a conduit excavated in the granite mass that the water rejoins the sea, through some cavities which we will use to our benefit. Yes, I will uncover it.”
The engineer cut a long branch, removed its leaves, and plunging it in at the corner between the two banks, he found that there existed an open hole only a foot under the surface of the water. This hole was the opening to the passageway vainly sought until then. 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 entrance to the passageway and I will open it.”
“How?” asked Gideon Spilett.
“By lowering the level of the lake by three feet.”
“And how will you lower the level?”
“By making a larger opening than this one.”
“Where, Cyrus?”
“On the part of the bank that is closest to the coast.”
“But it is a bank of granite,” noted the reporter.
“Well,” replied Cyrus Smith, “then I will blow up this granite, and the water, by escaping, will uncover this opening...”
“And form a waterfall which will fall on the beach,” added the reporter.
“A fall which we will utilize,” replied Cyrus. “Come, come!”
The engineer inspired his companion, whose confidence in Cyrus Smith was such that he did not doubt that the enterprise would succeed. Nevertheless, how would he disintegrate this bank of granite rocks without powder and with imperfect instruments? Wasn’t he attacking a problem beyond his resources?
When Cyrus Smith and the reporter returned to the Chimneys, they found Herbert and Pencroff occupied with unloading their wood.
“The woodsmen are finishing up, Mister Cyrus,” said the sailor laughing, “and when you need masons...”
“Masons, no, but chemists ,” replied the engineer.
“Yes,” added the reporter, “we will blow up the island...”
“Blow up the island!” cried Pencroff.
“A part of it, at any rate,” replied Gideon Spilett.
“Listen to me, my friends,” said the engineer.
And he made known to them the results of his observations. According to him, a more or less considerable cavity existed inside the mass of granite that supported Grand View Plateau and he intended to penetrate it. To do this, it was first necessary to clear the opening through which the water ran, and consequently to lower its level by making a larger opening. To do that, it was necessary to manufacture an explosive substance which could make a large opening at another point of the bank. It was this that Cyrus Smith was going to attempt by means of the minerals which nature had placed at his disposal.
It is needless to tell of the enthusiasm with which everyone, especially Pencroff, greeted this project. To use grand methods, rip open this granite, create a cascade, that appealed to the sailor. And he could just as easily be a chemist as a mason or a bootmaker since the engineer needed chemists. He would be anything that was wanted “even a professor of dance and deportment” he said to Neb, if that was ever necessary.
Neb and Pencroff were first directed to extract the fat from the dugong and to save its flesh, which was intended for food. They soon left without even asking for an explanation. Their confidence in the engineer was absolute.
A few minutes later, Cyrus Smith, Herbert and Gideon Spilett, dragging the hurdle and going up the river, went toward the bed of coal where schistous pyrites abounded. This was located among the more recent transition terrains where Cyrus Smith had already discovered a sample.
The entire day was employed in carting a certain quantity of these pyrites to the Chimneys. By evening they had several tons.
The next day, the 8th of May, the engineer began his manipulations. These schistous pyrites being principally composed of carbon, silicone, aluminum and iron sulphide, the latter in excess, he had to isolate the iron sulphide and transform it into sulphate as quickly as possible. The sulphate obtained, he could then extract sulphuric acid.
This in fact was the goal to be attained. Sulphuric acid is one of the most used agents, and the industrial importance of a nation can be measured by the consumption which is made of it. Later this acid would be very useful to the colonists in making candles, in the tanning of pelts, etc., but at the moment the engineer was reserving it for another use.
Cyrus Smith chose a location behind the Chimneys where the ground was carefully leveled. On this ground he placed a pile of branches and chopped wood on top of which were placed lumps of schistous pyrites supporting one another. Then he covered everything with a thin layer of pyrites previously reduced to walnut size.
That done, they set fire to the wood and the schists began to burn since they contained carbon and sulphur. Then new layers of crushed pyrites were put on to form an enormous pile. The exterior was covered with earth and grass after they had arranged some air vents, as if they were carbonizing a stack of wood to make charcoal.
Then they let the transformation proceed of its own accord and it needed not less than ten to twelve days for the iron sulphide to change into iron sulphate and the aluminum into aluminum sulphate, two substances equally soluble, the others, silicon, charcoal and cinders not being so.
While this chemical activity was going on, Cyrus Smith proceeded with other operations which were tackled by more than zeal. It was determination.
Neb and Pencroff had removed the fat from the dugong and collected it in large earthen jars. They now had to isolate one of its elements, glycerin, by saponifying it. Now to obtain this result, it suffices to treat it with soda or with lime. In fact, one or the other of these substances, after having attacked the grease, would form a soap thereby isolating the glycerin and it was precisely this glycerin that the engineer wished to obtain. As we know, lime was not lacking, but the treatment with lime would only give a lime soap, which was insoluble and consequently useless, whereas the treatment with soda would furnish, on the contrary, a soluble soap which would find use for domestic cleaning. Now, as a practical man, Cyrus Smith would rather try to obtain the soda. Was this difficult? No, because marine plants abounded on the shore, salicornia, ficoids and all those fucaceae which form the seaweed and the wrack. They therefore collected a large quantity of these plants, dried them first and burnt them in a pit in the open air. The combustion of these plants was kept up for several days so that the rising heat would fuze the cinders. The result of this incineration was a compact grayish mass, which for a long time has been known under the name of “natural soda.”
This result obtained, the engineer treated the grease with the soda, which gave on the one hand a soluble soap, and on the other hand this neutral substance, glycerin.
But this was not all. In view of his future preparation, Cyrus Smith still needed another substance, nitrate of potash, which is better known under the name of potassium nitrate, or saltpeter.
Cyrus Smith would have been able to make this substance by treating potassium carbonate, which is easily extracted from the cinders of plants, using nitric acid. But nitric acid was lacking and it was precisely this acid that he wished to obtain in the end. It was therefore a vicious circle that he would never leave. Very fortunately this time, nature furnished him with the saltpeter without which he would have been at quite a loss. Herbert discovered a bed in the north of the island at the foot of Mount Franklin, and they had nothing more to do but to purify this salt.
These various activities lasted for about eight days. They were finished before the transformation of the sulphide into iron sulphate was completed. During the days which followed, the colonists had time to make refractory pottery from plastic clay and to construct a brick furnace for the specific purpose of distilling the iron sulphate when that would be obtained. All this was completed about the 18th of May, a little before the chemical transformations were ended. Gideon Spilett, Herbert, Neb and Pencroff, ably directed by the engineer, became the most skillful workmen in the world. Of all masters, necessity is moreover the one that we listen to the most, and the one that teaches best.
When the pile of pyrites had been entirely reduced by the fire, the result of the operation consisted of iron sulphate, aluminum sulphate, silica, and a residue of charcoal and cinders which were placed in a basin full of water. They shook this mixture, let it settle, then on decanting it they obtained a clear liquid containing a solution of iron sulphate and aluminum sulphate, the other materials remaining as solids since they are insoluble. Finally, this liquid was vaporized in part, depositing the iron sulphate crystals. The original liquid, that is to say the nonvaporized portion which contained the aluminum sulphate, was abandoned.
Cyrus Smith thus had at his disposal a rather large quantity of iron sulphate crystals from which he would obtain sulphuric acid.
In industrial practice the manufacture of sulphuric acid requires a costly installation. In fact, it is necessary to have a large plant, special equipment, platinum apparatus, lead chambers which are not attacked by the acid in which to perform the operation, etc. The engineer did not have this equipment available but he knew that in Bohemia particularly they make sulphuric acid by a more simple means which also has the advantage of producing a high degree of concentration. It is known under the name of Nordhausen acid.
To obtain sulphuric acid, Cyrus Smith had only one operation to perform, to burn the iron sulphate crystals in a closed vessel so that the sulphuric acid would distill in a vapor and the vapor would then produce the acid by condensation.
For this manipulation they used the refractory pottery, in which they placed the crystals, and the forge, whose heat would distill the sulphuric acid. The operation was conducted perfectly and on the 20th of May, twelve days after having begun, the engineer possessed the agent that he counted on using later in various ways.
Now why did he want to have this agent? Very simply to produce nitric acid which was easy since the saltpeter, attacked by the sulphuric acid, would give him precisely this acid by distillation.
But finally what would he do with this nitric acid? His companions were still ignorant of this because he did not tell them about this last operation.
However, the engineer was within sight of his goal and one last operation would give him the substance that had taken so much effort.
After having taken the nitric acid and placed it in the presence of the glycerin, which had been previously concentrated by evaporation using a boiler, he obtained, even without using a cooler, several pints of an oily and yellowish liquid.
This last operation Cyrus Smith performed alone in a remote place far from the Chimneys because it presented the dangers of explosion, and when he brought a container of this liquid to his friends, he was content to say to them:
“This is nitroglycerin.”
“This is nitroglycerin.”
It was, in fact, this terrible product whose explosive power is perhaps tenfold that of ordinary powder and which has already caused so many accidents. Nevertheless, the means has since been found to transform it into dynamite, that is to say to mix it with a rather porous solid substance, clay or sugar, to retain it, so that the dangerous liquid can be used with more security. But dynamite was not yet known at the time the colonists were working on Lincoln Island.
“And it is this liquid which will blow up our rock?” asked Pencroff, rather incredulously.
“Yes, my friend,” replied the engineer, “and this nitroglycerin will produce such an effect that this extremely hard granite will be opposed by a larger explosive force.”
“And when will we see this, Mister Cyrus?”
“Tomorrow, after we have dug a hole for a mine,” replied the engineer.
The next day, the 21st of May, at daybreak, the miners returned to the point which was formed by the banks of Lake Grant and only five hundred feet from the coast. At this spot, the plateau was lower than the water which was held in place only by the granite frame. It was therefore evident that if they broke this frame, the water would escape by this opening and form a stream which, after flowing on the inclined surface of the plateau, would fall on the beach. This would then lower the general level of the lake which would uncover the opening of the passageway which was their final goal.
It was therefore the frame that they must break. Under the engineer’s direction, Pencroff, armed with a pick which he handled skillfully and vigorously, attacked the granite on its exterior face. The hole that he made took shape on a horizontal edge of the bank, excavated obliquely to produce a level appreciably lower than the water of the lake. In this way the explosive force would break the rock, permitting the water to escape freely to the outside and consequently lower its level sufficiently.
Pencroff, armed with a pick...
The work took a long time because the engineer, wanting to produce a formidable effect, did not count on using less than ten liters of nitroglycerin for the operation. But Pencroff, relieved by Neb, did so well that by about four o’clock in the afternoon, the hole for the mine was finished.
There still remained the problem of igniting the explosive substance. Ordinarily nitroglycerin is ignited by means of a fulminate primer which, on bursting, sets off the explosion. In fact, a shock is needed to provoke the explosion, and if it is simply set aflame, this substance will burn without exploding.
Cyrus Smith would certainly have been able to make a primer. In default of fulminate, he could easily obtain a substance analogous to cottonpowder, since he had nitric acid available. This substance, pressed into a cartridge and introduced into the nitroglycerin, would ignite by means of a fuze and set off the explosion.
But Cyrus Smith knew that nitroglycerin has the property of detonating under shock. He therefore resolved to utilize this property, but he would use another means if this one did not succeed.
In fact, the shock from a hammer on a few drops of nitroglycerin sprinkled on the surface of a hard stone suffices to induce the explosion. But the operator cannot be there to give the blow of the hammer without becoming victim to the operation. Cyrus Smith then thought of suspending a mass of iron weighing several pounds onto a post above the hole of the mine by means of a vegetable fiber. Another long fiber, previously dipped in sulphur, was attached by one of its extremities to the middle of the first fiber while the other extremity trailed along the ground to a distance of several feet from the hole of the mine. The fire being kindled to this second fiber, it would burn until it reached the first. This one, then catching fire in its turn, would break and the mass of iron would fall on the nitroglycerin.
This apparatus was so installed; then the engineer, after having dismissed his companions, filled the hole of the mine so that the nitroglycerin came up to the top and he threw a few drops on the surface of the rock below the suspended mass of iron.
That done, Cyrus Smith took the end of the sulphurized fiber, lit it, and leaving the place, he returned to his companions in the Chimneys.
And, leaving the place, Cyrus Smith...
The fiber was set to burn for twenty five minutes and, in fact, twenty five minutes later an explosion resounded, impossible to describe. It seemed that the entire island trembled on its base. Rocks flew up as if vomited from a volcano. The vibration produced by the displaced air was such that the rocks at the Chimneys oscillated. The colonists, even though they were more than two miles from the mine, were thrown to the ground.
They got up, climbed to the plateau and ran to the spot where the edge of the lake had been ripped open by the explosion...
Three hurrahs escaped from their chests. The granite frame split over a large area. A rapid stream of water was escaping through it, flowing and foaming across the plateau, and upon reaching the crest it fell from a height of three hundred feet on to the beach.
![[prev]](../pics/left2.gif){kind=small}
![[up]](../pics/up2.gif){kind=small}
![[next]](../pics/right2.gif){kind=small}
