Primitive Man Part 33

Then remarking that since that epoch the cone had increased 3 feet 6 inches, and always going upon the hypothesis that the increase was the same as in subsequent ages, he came to the conclusion that the bed corresponding with the bronze epoch was at least 2900 and at the most 4200 years old; and that the layer belonging to the Stone Age, forming the entire remainder of the cone, was from 4700 to 10,000 years old.

Another calculation, the conclusions of which agree tolerably well with these, was made by M. Gillieron, professor at the college of Neuveville.

We have already said that the remains of a pile-work belonging to the Stone Age was discovered near the bridge of Thiele, between the lakes of Bienne and Neuchatel. It is evident that the valley, the narrowest part of which was occupied by the lacustrine settlement, was formerly almost entirely under water, for below this point it suddenly widens out and retains these proportions as far as the lake of Bienne. The lake must, therefore, have retired slowly and regularly, as may be ascertained from an examination of the mud deposited by it. If, therefore, we know its annual coefficient of retreat, that is to say, how much it retired every year, we should be able to estimate with a sufficient degree of approximation the age of the settlement of the bridge of Thiele.

Now there is, not far from the lake, at about 1230 feet from the present sh.o.r.e, an old abbey, that of Saint-Jean, which is known to have been built about the year 1100. A doc.u.ment of that time mentions that the cloister had the right of fis.h.i.+ng in a certain part of the lake; and there is some likelihood that it was built on the edge of the lake; a supposition which naturally presents itself to the mind. The lake, then, must have retired 1230 feet in 750 years. This granted, M.

Gillieron easily calculated the time which would be taken for a retreat of 11,072 feet, this number representing the distance from the present sh.o.r.e to the entrance of the defile which contains the settlement of the bridge of Thiele. He found by this means that the settlement is at least 6750 years old, a figure which confirms those of Morlot.

The preceding calculations a.s.sign to the Stone Age in Switzerland an antiquity of 6000 to 7000 years before the Christian era, and to the bronze epoch an antiquity of 4000 years before the same era. There is still much uncertainty in the figures thus given to satisfy public curiosity; but there is at least one fact which is altogether unquestionable--that these calculations have dealt a fatal blow to recognised chronology.

FOOTNOTE:

[38] 'Le Danemark a l'Exposition Universelle de 1867, by Valdemar Schmidt,' vol. i. pp. 60-64. Paris, 1868.

II.

THE IRON EPOCH.

CHAPTER I.

Essential Characteristics of the Iron Epoch--Preparation of Iron in Pre-historic Times--Discovery of Silver and Lead--Earthenware made on the Potter's Wheel--Invention of Coined Money.

Without metals, as we have said in one of the preceding chapters, man must have remained for ever in a state of barbarism. To this we must add, that the civilisation of man has made progress just in proportion to the degree of perfection he has arrived at in the working of the metals and alloys which he has had at his disposal. The knowledge and use of bronze communicated a strong impulse to nascent civilisation, and was the means of founding the first human communities. But bronze is far from possessing all the qualities which ought to belong to metals when applied to various industrial purposes. This alloy is neither hard nor elastic enough to make good tools; and, in addition to this, it is composed of metals which in a natural state are very scarce. Man requires a metal which is cheap, hard, easy to work, and adapted to all the requirements which are exacted by industrial skill, which is so manifold in its works and wants.

A metal of this sort was at length discovered, and a new era opened for the future of men. They learned how to extract from its ore iron--the true king of metals, as it may well be called--on account of its inestimable qualities. From the day when iron was first placed at man's disposal civilisation began to make its longest strides, and as the working of this metal improved, so the dominion of man--his faculties and his intellectual activity--likewise enlarged in the same proportion.

It is, therefore, with good reason that the name of _Iron Epoch_ has been given to the latest period of the development of primitive man, and it is not surprising that the last portion of the iron epoch formed the commencement of historical times. After this period, in fact, man ceased to live in that half-savage state, the most striking features of which we have endeavoured to portray.

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 fas.h.i.+oned 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 princ.i.p.al 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 subst.i.tution 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 aerolites 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 aerolites which have been met with in their country small quant.i.ties 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 aerolites.[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 ma.s.s 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 quant.i.ty 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 ma.s.s 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 ma.s.s 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 'Memoires sur l'Archeologie 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.

By increasing the size of the apparatus used, far more considerable results were of course obtained. In Dalecarlia (Sweden), M. Morlot found smelting-houses, so to speak, in which the original hole, of which we have just been speaking, is surrounded with stones so as to form a sort of circular receptacle. In this rough stone crucible layers of charcoal and iron-ore were placed in succession. After having burnt for some hours, the heap was searched over and the spongy iron was found mixed with the ashes at the bottom of the furnace.

The slowness of the operation and the inconsiderable metallic result induced them to increase the size of the stone receptacle. They first gave to it a depth of 7 feet and then of 13 feet, and, at the same time, coated the walls of it with clay. They thus had at their disposal a kind of vast circular crucible, in which they placed successive layers of iron-ore and wood or charcoal.

In this altogether elementary arrangement no use was made, as it seems, of the bellows. This amounts to stating that the primitive method of smelting iron was not, as is commonly thought, an adaptation of the _Catalan furnace_. This latter process, which, even in the present time, is made use of in the Pyrenean smelting works, does not date back further than the times of the Roman empire. It is based on the continual action of the bellows; whilst in the pre-historic furnaces this instrument, we will again repeat, was never employed.

These primitive furnaces applied to the reduction of iron-ore, traces of which had been recognised by Morlot, the naturalist, in Austria and Sweden, have lately been discovered in considerable numbers in the canton of Berne by M. Quiquerez, a scientific mining engineer. They consist of cylindrical excavations, of no great depth, dug out on the side of a hill and surmounted by a clay funnel of conical form.

Wood-charcoal was the fuel employed for charging the furnaces, for stores of this combustible are always found lying round the ancient smelting works.

In an extremely curious memoir, which was published in 1866 by the Jura Society of Emulation, under the t.i.tle of 'Recherches sur les anciennes Forges du Jura Bernois,' M. Quiquerez summed up the results of his protracted and minute investigations. A few extracts from this valuable work will bring to our knowledge the real construction of the furnaces used by pre-historic man; 400 of these furnaces having been discovered by M. Quiquerez in the district of the Bernese Jura.

We will, however, previously mention that M. Quiquerez had represented, or materialised, as it were, the results of his interesting labours, by constructing a model in miniature of a siderurgical establishment belonging to the earliest iron epoch. This curious specimen of workmans.h.i.+p showed the clay-furnace placed against the side of a hill, the heaps of charcoal, the scoriae, the hut used as a dwelling by the workmen, the furnace-implements--in short, all the details which formed the result of the patient researches of the learned Swiss engineer.

M. Quiquerez had prepared this interesting model of the ancient industrial pursuits of man with a view of exhibiting it in the _Exposition Universelle_ of 1867, together with the very substances, productions, and implements which he had found in his explorations in the Jura. But the commission appointed for selecting objects for admission refused to grant him the modest square yard of area which he required for placing his model. How ridiculous it seems! In the immense Champ de Mars in which so many useless and absurd objects perfectly swarmed, one square yard of s.p.a.ce was refused for one of the most curious productions which was ever turned out by the skilful hands of any _savant_!

The result of this unintelligent refusal was that M. Quiquerez' model did not make its appearance in the _Exposition Universelle_ in the Champ de Mars, and that it was missing from the curious Gallery of the History of Labour, which called forth so much of the attention of the public.

For our readers, however, it will not be altogether lost. M. Quiquerez has been good enough to forward to us from Bellerive, where he resides (near Delemont, canton of Basle, Switzerland) a photograph of his curious model of a pre-historic workshop for the preparation of iron.

From this photograph we have designed the annexed plate, representing a _primitive furnace for the extraction of iron_.

[Ill.u.s.tration: Fig. 231.--Primitive Furnace for Smelting Iron.]

This composition reproduces with tolerable accuracy the model in relief constructed by the author. The furnace is shown; it is nothing but a simple cavity surmounted by a conical chimney-funnel, and placed against the side of a hill. Steps made of rough stone, placed on each side of the mound, enable the workmen to mount to the summit. The height of the funnel is about 9 feet. At the side of the furnace stands the hut for the labourers, constructed of a number of round poles placed side by side; for centuries past huts of this kind have been erected in almost every country.

On the right, in the foreground, we may notice a heap of charcoal intended to be placed in the furnace in order to reduce the ore; on the left, there is the store of ore called in the ironworks the _ore-pen_.

The provision of iron-ore is enclosed between four wooden slabs, forming a quadrangular s.p.a.ce. In the centre are the scoriae which result from the operations carried on. A workman is extracting the cake of spongy iron from the ashes of the furnace; another is hammering on the anvil a piece of iron drawn from the furnace in order to forge it into a bar. Round the furnace various implements are scattered about, such as the anvil, the pincers, the hammer, &c. All the instruments are designed from various specimens found by the author.

After these explanations, we may now give some extracts from M.

Quiquerez' work, and we trust our readers will find no difficulty in comprehending the details given by the learned engineer, describing the primitive furnaces for the extraction of iron which he discovered in the Bernese Jura.

M. Quiquerez has remarked two kinds of primitive furnaces for the fabrication of iron, or, rather, two stages of improvement in their construction. The first sort, that which the author considers as dating back to the most remote antiquity, is not so numerous as the others; the second kind form the largest number of those which he has explored.

"Furnaces of the first kind," says M. Quiquerez, "consisted of nothing but a small cylindrical excavation of no great regularity in shape, with a cup-shaped bottom, hollowed out in the side of a hill so as to give more natural height on one side; the front of the furnace was closed up by fire-proof clay, supported with stones. This cavity was plastered over with 4 to 6 inches of clay, generally of a whitish colour, which became red after coming in contact with the fire. These smelting-furnaces were not more than 12 to 18 inches in depth, as seemed to be shown by the upper edges being rounded and more or less scoriated.

The front, which was always more or less broken, had an opening at its base to admit a current of air, and to allow the workmen to deal with the melted material; but this opening seems to show that the piece of metal which had been formed during the operation must have been extracted by breaking in the front.

"The second kind of furnace, which is by far the most numerously found and widely distributed, is, in fact, nothing but an improvement of that which preceded it, the edges of the furnace or crucible being considerably raised in height. They vary in depth from 7-1/2 to 8 feet, with a diameter of most irregular dimensions, from 18 inches upwards, and a thickness of 12 inches to 7 feet. They are likewise formed of fire-proof clay, and their average capacity is about 25 gallons.

"The constructor, having dug out in the side of the hill an opening circular, or rather semi-circular, at the base, with a diameter nearly three times as wide as the future furnace, arranged in the centre of this hole a kind of furnace-bed made of plastic clay at bottom, and covered with a layer of fire-proof clay on the top of it. The bed of the furnace, which lies on the natural and hardly levelled earth, is, generally speaking, not so thick as the side walls, which are formed of sandy or siliceous clay, always fire-proof on the inside, but sometimes of a more plastic nature on the exterior; the empty s.p.a.ce left between the walls of the furnace and the solid ground round it was filled up with earth and other material. In front the furnace was enclosed by a rough wall, sometimes straight and sometimes curving, built, without mortar, of rough limestone, and dressed with earth to fill up the gaps.

In front of the furnace an opening was made in this wall, taking its rise a few inches above the bottom of the furnace, and increasing in size in an outward direction, so as to enable the workmen to see into, and work in, the furnace.