Primitive Man

by Louis Figuier

As the use of iron essentially characterises this epoch in the history of mankind, we ought to give an account of the processes of manufacture employed by the primitive metallurgists, that is to say, we should inquire how they proceeded at this epoch to extract iron from its native ore.

The art of metallurgy had made great progress during the bronze epoch. There were at that time considerable workshops for the preparation of bronze, and small foundries for melting and casting this alloy. When once formed into weapons, instruments, and tools, bronze objects were fashioned by artisans of various professions. The moulder's art had already attained to a high degree of perfection, a fact which is proved by the gigantic bronze objects which we have already mentioned, as well as the castings, so many of which have been represented in the preceding pages. The phenomenon of tempering was well known, that is the principal modifications which are experienced by bronze in its cooling, whether slow or sudden. It was well known how to vary the proportions of the tin and copper so as to obtain bronze of different degrees of hardness. All the means of soldering were also familiarly known. Damascening was introduced in order to diversify the appearance of wrought metallic objects. The cutting qualities of instruments were increased by forging them and consolidating them by hammering. They had even gone so far as to discover the utility of the addition of certain mineral salts in the founder's crucible in order to facilitate the fusion of the bronze.

Thus at the end of the bronze epoch the knowledge of metals had attained to a comparatively considerable development. Hence we may conclude that the substitution of iron for bronze took place without any great difficulty. Owing to the natural progress and successive improvements made in metallurgic art, the blacksmith made his appearance on the scene and took the place of the bronze-moulder.

What, however, was the process which enabled our earliest metallurgists to extract iron from its native ore?

Native iron, that is metallic iron in a natural state, is eminently rare; except in aërolites it is scarcely ever found. According to Pallas, the Russian naturalist, certain Siberian tribes have succeeded, with a great amount of labour, in obtaining from the aërolites which have been met with in their country small quantities of iron, which they have made into knives. The same practice existed among the Laplanders. Lastly, we are told by Amerigo Vespucci that in the fifteenth century the Indians at the mouth of the La Plata river were in the habit of making arrow-heads and other instruments with iron extracted from aërolites.[39]

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 3½ 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.

This same process for the extraction of iron from its natural oxide, without fusion, is practised by the negroes of Fouta-Djallon, in Senegal.

After having become acquainted with the elementary process which is practised by the semi-barbarous tribes of the present day, we shall find but little difficulty in understanding all that Morlot, the Swiss naturalist, has said as to the iron-furnaces of pre-historic man, and shall probably agree in his opinions on the subject. Morlot, in his 'Mémoires sur l'Archéologie de la Suisse,' has described the vestiges of the pre-historic furnaces intended for the preparation of iron, which were found by him in Carinthia (Austria).

According to M. Morlot, the plan adopted for extracting iron from its oxide in pre-historic times was as follows:—On the side of a slope exposed to the wind, a hole was hollowed out. The bottom of this hole was filled up with a heap of wood, on which was placed a layer of ore. This layer of ore was covered by a second heap of wood; then, taking advantage of a strong breeze rising, which had to perform the functions of the bellows, the lowest pile of wood was kindled at its base. The wood by its combustion was converted into charcoal, and this charcoal, under the influence of heat, soon reduced the iron oxide to a metallic state. When the combustion had come to an end, a few pieces of iron were found among the ashes.