In this way, under the influence of the air projected by the blowing-machine, the coal would be transformed into carbonic acid, then into oxide of carbon, its use being to reduce the oxide of iron, that is to say, to rid it of the oxygen.
Thus the engineer proceeded. The bellows of sealskin, furnished at its extremity with a nozzle of clay, which had been previously fabricated in the pottery kiln, was established near the heap of ore. Using the mechanism which consisted of a frame, cords of fiber and counterpoise, he threw into the mass an abundance of air, which by raising the temperature also concurred with the chemical transformation to produce in time pure iron.
The operation was difficult. All the patience, all the ingenuity of the settlers was needed; but at last it succeeded, and the result was a lump of iron, reduced to a spongy state, which it was necessary to shingle and fagot, that is to say, to forge so as to expel from it the liquefied veinstone. These amateur smiths had, of course, no hammer; but they were in no worse a situation than the first metallurgist, and therefore did what, no doubt, he had to do.
A handle was fixed to the first lump, and was used as a hammer to forge the second on a granite anvil, and thus they obtained a coarse but useful metal. At length, after many trials and much fatigue, on the 25th of April several bars of iron were forged, and transformed into tools, crowbars, pincers, pickaxes, spades, etc., which Pencroft and Neb declared to be real jewels. But the metal was not yet in its most serviceable state, that is, of steel. Now steel is a combination of iron and coal, which is extracted, either from the liquid ore, by taking from it the excess of coal, or from the iron by adding to it the coal which was wanting. The first, obtained by the decarburation of the metal, gives natural or puddled steel; the second, produced by the carburation of the iron, gives steel of cementation.
It was the last which Cyrus Harding intended to forge, as he possessed iron in a pure state. He succeeded by heating the metal with powdered coal in a crucible which had previously been manufactured from clay suitable for the purpose.
He then worked this steel, which is malleable both when hot or cold, with the hammer. Neb and Pencroft, cleverly directed, made hatchets, which, heated red-hot, and plunged suddenly into cold water, acquired an excellent temper.
Other instruments, of course roughly fashioned, were also manufactured; blades for planes, axes, hatchets, pieces of steel to be transformed into saws, chisels; then iron for spades, pickaxes, hammers, nails, etc. At last, on the 5th of May, the metallic period ended, the smiths returned to the Chimneys, and new work would soon authorize them to take a fresh title.
Chapter 16
It was the 6th of May, a day which corresponds to the 6th of November in the countries of the Northern Hemisphere. The sky had been obscured for some days, and it was of importance to make preparations for the winter. However, the temperature was not as yet much lower, and a centigrade thermometer, transported to Lincoln Island, would still have marked an average of ten to twelve degrees above zero. This was not surprising, since Lincoln Island, probably situated between the thirty-fifth and fortieth parallel, would be subject, in the Southern Hemisphere, to the same climate as Sicily or Greece in the Northern Hemisphere. But as Greece and Sicily have severe cold, producing snow and ice, so doubtless would Lincoln Island in the severest part of the winter and it was advisable to provide against it.
In any case if cold did not yet threaten them, the rainy season would begin, and on this lonely island, exposed to all the fury of the elements, in mid-ocean, bad weather would be frequent, and probably terrible. The question of a more comfortable dwelling than the Chimneys must therefore be seriously considered and promptly resolved on.
Pencroft, naturally, had some predilection for the retreat which he had discovered, but he well understood that another must be found.