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