Metals are not generally found in the ground in a pure state. For the most part they are combined with oxygen or sulphur. Such was the case with the two specimens which Cyrus Harding had brought back, one of magnetic iron, not carbonated, the other a pyrite, also called sulphuret of iron. It was, therefore the first, the oxide of iron, which they must reduce with coal, that is to say, get rid of the oxygen, to obtain it in a pure state. This reduction is made by subjecting the ore with coal to a high temperature, either by the rapid and easy Catalan method, which has the advantage of transforming the ore into iron in a single operation, or by the blast furnace, which first smelts the ore, then changes it into iron, by carrying away the three to four per cent. of coal, which is combined with it. Now Cyrus Harding wanted iron, and he wished to obtain it as soon as possible. The ore which he had picked up was in itself very pure and rich. It was the oxydulous iron, which is found in confused masses of a deep gray color; it gives a black dust, crystallized in the form of the regular octahedron. Native lodestones consist of this ore, and iron of the first quality is made in Europe from that with which Sweden and Norway are so abundantly supplied. Not far from this vein was the vein of coal already made use of by the settlers. The ingredients for the manufacture being close together would greatly facilitate the treatment of the ore. This is the cause of the wealth of the mines in Great Britain, where the coal aids the manufacture of the metal extracted from the same soil at the same time as itself. “Then, captain,” said Pencroft, “we are going to work iron ore?” “Yes, my friend,” replied the engineer, “and for that--something which will please you--we must begin by having a seal hunt on the islet.” “A seal hunt!” cried the sailor, turning towards Gideon Spilett. “Are seals needed to make iron?” “Since Cyrus has said so!” replied the reporter. But the engineer had already left the Chimneys, and Pencroft prepared for the seal hunt, without having received any other explanation. Cyrus Harding, Herbert, Gideon Spilett, Neb, and the sailor were soon collected on the shore, at a place where the channel left a ford passable at low tide. The hunters could therefore traverse it without getting wet higher than the knee. Harding then put his foot on the islet for the first, and his companions for the second time.