But, as we hardly need observe, stones of this kind do not often drop down from the skies, and their employment is of too accidental a character ever to have suggested to men the right mode of the extraction of iron. It is, therefore, almost certain that the first iron used was extracted from its ore just like copper and tin, that is, by the reduction of its oxide under the influence of heat and charcoal. In opposition to this explanation, some bring forward as an objection the prodigiously high temperature which is required for the fusion of iron, or, in fact, the almost impossibility of melting iron in the primitive furnaces. But the fusion of iron was in no way necessary for the extraction of this metal; and if it had been requisite to procure liquid iron, primitive industrial skill would never have succeeded in doing it. All that was necessary was so to reduce the oxide of iron as to obtain the metal in a spongy state without any fusion. The hammering of this spongy mass when in a red-hot state soon converted it into a real bar of iron. If we cast a glance on the metallurgic industry of some of the semi-barbarous nations of ancient times, we shall find, as regards the extraction of iron, a process in use among them which will fully justify the idea we have formed of the way in which iron must have been obtained in primitive times. Gmelin, the naturalist, during his travels in Tartary, was a witness of the elementary process which was employed by these northern tribes in procuring iron. There, every one prepares his own iron just as every household might make its own bread. The furnace for the extraction of iron is placed in the kitchen, and is nothing but a mere cavity, 9 inches cube, which is filled up with iron-ore; the furnace is surmounted by an earthen chimney, and there is a door in front of the furnace for introducing the ore, this door being kept closed during the smelting process. In an orifice at the side the nozzle of a pair of bellows is inserted, which are blown by one man whilst another introduces the ore and charcoal in successive layers. The furnace never holds more than 3-1/2 lbs. of ore for each operation. When this quantity has been placed in the furnace, in small pieces one after the other, all that is done is keeping up the action of the bellows for some minutes. Lastly, the door of the furnace is opened, and the ashes and other products of combustion having been drawn out, a small mass of spongy iron is found, which proceeds from the reduction of the oxide of iron by means of the charcoal, without the metal being in a state of fusion, properly so called. This small lump of iron was cleaned with a piece of wood, and was put on one side to be subsequently welded to others, and hammered several times when in a red-hot state; and by means of several forgings the whole mass was converted into a single bar.