of their cotton garments, they were obliged to have recourse! Iron differs from the metals we have mentioned as earliest known, by its occurring rarely in a metallic state, and being then most difficult of fusion: its uses were in consequence a later discovery. The methods, besides, of disengaging it from the ores in which it is usually found in nature, are far from being obvious, consisting of various processes,--such as pounding, roasting, smelting in contact with charcoal, to render it fusible; requiring too, additional heatings and hammerings to render it malleable, and a still more complicated process to convert it into steel. Yet it was in use, as has been remarked, in very remote ages: Moses, in Deuteronomy, makes frequent mention of it. He speaks of mines of iron, and alludes to furnaces for melting it; and from the circumstance of swords, knives, axes, and tools for cutting stone, constructed of that metal, being mentioned by the same authority, we are entitled to conclude that the art of tempering and converting it into steel was also known. The mode of tempering it was certainly known to the Greeks as early as the days of Homer; for that poet borrows from the art some of his similes. Thus in the Oddyssey: And as, when arm'rers temper in the ford The keen-edged pole-axe, or the shining sword, The red hot metal hisses in the lake, So in his eye-ball hiss'd the plunging stake. It is by its conversion into steel, that we are furnished with a material retentive of an edge, and adapted to cutting the hardest substances, and are enabled to fabricate that most important class of implements, edge-tools, all of which, from the ponderous pit saw to the finest lancet, are formed in part with this metal. It was not, however, until very late in modern times, that we may be said to have acquired absolute dominion over this individual of the mineral kingdom, so as to be able at command, to press it into service, whatever may be its locality, in relation to the surface of the earth or its interior. For, before the improvements made in the steam-engine by the discoveries of Watts, we were limited in the power of availing ourselves of the known existence of iron, however abundant in any particular spot, by the necessity of the concurrence of a stream of water in the same location with that of the metal, as a means of impelling the machinery for producing the blast requisite in the operation of smelting. Since those improvements, steam power may be employed wherever the ore and fuel is found in sufficient quantities to authorize the erection of furnaces; and the manufacture of iron has in consequence, especially in Great Britain, risen into great importance. The annual produce of smelted ore in that kingdom, is estimated now to be about seven hundred thousand tons.