Popular Science Monthly/Volume 25/May 1884/The Beginnings of Metallurgy
|THE BEGINNINGS OF METALLURGY.|
FROM recognized cosmical conditions, we conclude that the earth, like the other bodies in the universe, was originally a mass of vapor, which has undergone gradual cooling, condensation, and solidification. The heavier parts collected into a core, which, very likely resembling meteoric iron, was in the primeval epoch covered with glowing liquid masses of silicates, and the whole was surrounded by dense vapors. As the solidification proceeded, the ocean was deposited from the vaporous envelope, while the rarer atmosphere remained above. Both these elements are still mobile, and afford media for organic life.
The stratification of the rocks follows the existence of the ocean. The water dissolves matter out of the silicate crust and deposits it again. Thus have been and are still formed shales, sandstones, and limestones. The depositions have not, however, gone on without interruption; but the sedimentary beds have in all periods down to our own day been at times broken through by eruptions of the underlying silicates. Hence we meet so frequently in the various formations alternate masses of sedimentary and eruptive rocks. Both kinds have been used by men from the earliest times in tools and as building materials. On the one hand, stones have been employed in slabs and blocks in the construction of houses and walls, to mark graves, and for altars; on the other hand, smaller stones and flakes have been fashioned into instruments for beating and slinging; tough stones having weight have served as hammers, sharp chips of flint and obsidian for cutting and boring and piercing instruments. By the contrivance of these instruments man put himself in a condition to perform numerous operations. The ancient Egyptians, the Central-American races, and other civilized peoples certainly executed a large part of their works in stone with stone tools. Even the smoothing and polishing and the boring and sawing of stones do not necessarily require metallic tools, but were all formerly done with instruments of stone and wood.
It was believed a little while ago that the stone age was superseded by a bronze age. A closer examination of the subject has made it clear that we have in this case to deal not with sharply distinguished intervals, but with different degrees and conditions of civilization, which existed at the same time among different nations, and even among different classes of the same nation. Stone tools and weapons were still in use in Northern Europe long after the hard metals had become common in the South; but even in Southern Europe the poorer classes continued to use stone implements till late in historical times.
Survivals of stone-age civilization are now met with among only a few peoples; men have as a rule advanced to the metal-using stage, which has acquired its significance in consequence of the production of the hard metals. It is our purpose to review the origin, the acquisition, and the application of these important materials.
I have already spoken of the core of the earth as consisting chiefly of iron, while the crust is composed of eruptive silicates. The fluid from which these masses have been derived is a mixture of several combinations, the principal elements of which are oxygen, silicon, the lighter earth and alkali metals, and the heavier metal, iron. Oxygen predominates, and is combined with the other elements into stony oxides. The excess of oxygen floats around the oxidized dead-burned globe as life-air. I have mentioned only iron among the heavy metals important in civilization because it is the one that plays the most important part in the composition of the rocks. We also find smaller masses of other heavy metals in the primitive matter of the earth. Most of them appear sparsely distributed in the eruptive rocks in combination with sulphur, but a few occur in oxides. Besides these we also find ores concentrated in crevices and in pockets in rock-masses of different kinds, where they have been carried in aqueous solution. These local accumulations of ores first made it possible for men to obtain the rarer metals in masses and apply them to use. The metallic sulphurets nearer to the surface have been changed by atmospheric action partly into the simple metals, partly into oxides. This was a fact of great importance in the beginnings of metallurgic art; for the oxides are much easier to reduce to the condition of pure metal than the sulphurets. The unmixed metals—the precious metals and copper —are, of course, immediately available, and can be brought into any form that may be desired by hammering or casting. But little advantage was, however, derived from this circumstance. The first decisive step was not made till the hard metals, bronze and iron, were produced. These substances could not, however, be obtained at once, for neither the tin required for the manufacture of bronze nor iron in the metallic state was at hand; and it was a great step when the thought first occurred to man of separating the metallic elements from their stony ores. The myths of different nations generally indicate a god or a hero as the inventor of metallurgy; but it is now hardly doubtful that this god was in most cases a human mind directed by some accident.
Tin, iron, and the other metals, as we have said, do not occur pure, but as oxides in stone. They have a strong affinity for oxygen, and can not be separated from it and produced in a metallic condition, except by the aid of powerful reagents. There is one element which has a stronger affinity for oxygen than any metal—glowing charcoal, which, in the contest with the metallic oxide, wrests the oxygen from it. In the innumerable places where the primitive man—hunter, fisher, or nomad—built his fires, there can not have failed to be some where the red-hot coals would lie upon a soil containing ores. This would be sufficient to reveal the metallic treasure. By the occurrence of accidents of this kind, men learned to recognize the metal, and in a similar way how to extract it from the earth.
Of the two hard metals we have named, bronze came earlier into use, while the fabrication of iron belongs to a later period of civilization. It has been thought strange that bronze, a compound of two constituents, should have been got and used earlier than the simple metal, iron. And it has been objected that the former product is generally too soft to be valuable for weapons and tools, that pure copper is hard to get, and that tin-ore occurs in only a few places. All of these objections must yield to historical facts; and they can not be upheld against opposing geological considerations. First, it is not true that an alloy is harder to produce than a single metal. Man must in the beginning have melted up together the ores of different kinds as they occurred associated in nature, and thus have obtained a variety of alloys. Among others, copper and tin ores occur near each other in several regions. In such places bronze would have been produced, at first accidentally, afterward on purpose. In other places, where these metals are not naturally associated, one or the other of the constituents, or perhaps the alloy already formed, had to be imported. The second objection is no less fallacious: if substances containing phosphorus are melted up with the ores, the resultant product will have considerable hardness, which may be increased by repeated tempering and hammering. The third objection rests on observations in the most famous copper districts of Europe. It must be remembered in respect to the mines of these regions, that the operations have been carried on for a long time at a great depth, where the sulphurous copper-ores are, it is true, very hard to utilize. But in former times the ores lay nearer to the surface, and they were, in the degree that they were exposed, purified and made more reducible by atmospheric agencies. Oxides, carbonates, and pure copper were to be found. They were easy to smelt, and gave a pure product. It must also be remembered that tin was not so scarce in the earliest times as it is now; and there are still many places where it is not profitable to mine, that afford washings of tin of considerable richness. "We thus see that the metal was useful, and that there was a sufficiency of rich, easily-worked ores. The conditions were, then, favorable for a long blossoming of the civilization of the bronze age.
The oldest historical information on this subject is furnished to us by the Egyptian inscriptions. From them we conclude that that highly civilized nation was in possession of metals from the beginning of its history. While the Indian Indra appears armed with the thunderbolt, "Akman" of meteoric stone, and the German god, Thor, carries his stone Mjőlnir, the Egyptian gods are provided with metallic weapons; an evidence that the people were already acquainted with metals. Moreover, we find the spear designated after the name of a metal in the earliest inscriptions. As we say of weapons, "the sharp steel," as the Greeks and Romans described their weapons as of bronze and later of iron, so the Egyptians designated their lances by the name of bronze, and when describing bronze gave the sign for a metal, and explained it by the addition of that for a lance. Bronze was the prevailing metal. The metallic vessels, tools, and weapons of the ancient empire are represented in red, not in blue. It was the same essentially in the new empire, although the Egyptians had then become acquainted with articles of iron, and had obtained them by conquest and trade.
We meet this form of civilization again in reviewing the history of Mesopotamia and Syria. Babylon ruled over an alluvial plain, and was obliged to get all its metals from abroad by trade or conquest; Assyria possessed copper and iron within its own territory, but was dependent on other countries for tin. The countries whence this metal was obtained in antiquity were Midian, the Hindoo-Koosh, Farther India, and, at a later period, Spain and Britain; but the Phœnicians managed and controlled the trade in the indispensable mixed metal. Inasmuch as one of the essential metals was not found within the territories of the old nations of civilization, it will not do to ascribe the discovery of the manufacture of bronze to them. We must unquestionably look for the metallurgists of primeval times in other countries; and, in fact, traditions are not wanting to support such an assumption. The Hittites are mentioned by the Egyptians as the iron-workers of ancient times. The Mosaic books mention Tubal-Cain (a personified people) as the inventors and masters of metallurgy; and the Greeks designate, not the Phœnicians nor the Babylonians or Egyptians, but the Phrygians, as the ancient masters of art in bronze and iron, and praise the Chalybes of the Black Sea as distinguished steel-smiths.
Reviewing the facts we have so far adduced, we find that we have ascertained, first, that the ancient nations of civilization were predominantly in a bronze age; second, that they were dependent on other nations for the production of bronze; and, third, that peoples strange to them were practiced in iron-working at a period when they were still using only bronze. The metallurgy of the hard metals as a whole was thus originally not wrought out by the civilized peoples of whom we know the most, but by tribes who do not play so great a part in history; by peoples who have not been perpetuated in fame by having founded great states, or by imperishable monuments or written records, but whose contribution to the world's advancement consists in the fact that, living in lands rich in metals, they discovered and developed the processes for working them.
I have sketched the metal-culture of the East as it represented itself to us at a time when the prehistoric stone age and a deep barbarism still almost exclusively prevailed in Europe. We now turn to the Indo-Germanic peoples, among whom we shall consider the Greeks in particular, and the other nations collectively. These peoples make their appearance late on the scene of history, and their myths play about a time when the Semito-Hamitic states had already left behind them the traces of a long civilization. We may, however, safely assume that many of the tribes had practiced metallurgy for three or four thousand years. We come to this conclusion from the fact that several of the peoples had the same names for the metals. They must therefore have been acquainted with metals and used them in their ancient common Asiatic home. This is confirmed by the Greek myths, which mention the Phrygians, who were settled in Asia Minor and on the adjoining islands, as the oldest metal-workers and the instructors of the Hellenes. They worked not only in bronze, but also in iron. The Indians also seem, at least just after the Buddhist reformation, to have been good iron-workers. Analogous conditions appear to have existed in Europe, where single peoples, at a relatively early period, even before the immigration, possessed metals, and when the remarkable fact meets us frequently that particular tribes (in contrariety to the mass of the ancient civilized peoples) obtained and worked iron.
We next consider the case of the Greeks, who are highly interesting to the historian of civilization not only by their great individuality but also by their multifarious relations with Eastern civilization. The original inhabitants of the country in which this important people settled appear to have been the Pelasgians, who may also be regarded as earlier immigrants of the Indo-European race. The Greeks probably learned the so-called Cyclopean architecture from them, but nothing supports the belief that they were influenced in metal-working by them. The Greeks obtained their start in those arts from the islanders and the Semites of the Asiatic coast through trade and colonization.
The most ancient settler in Greece is said to have been Cecrops, who came from Egypt in the second millennium before Christ. He founded Athens and gave laws to the people. From the same country came Danaus, who founded Argos. Pelops came from metal-rich Phrygia. His sons conquered Mycenæ. A Semitic life also ruled in Orchomenos a few generations before the Trojan War. The city was wealthy, and the extensive plain was made tillable by an extensive system of aqueducts. Thebes, which was also founded by immigrants from the East, was the rival of this colony. The mythical hero Cadmus built the Cadmeian citadel and surrounded the city with the famous walls; he taught the nomadic people agriculture and the Phoenician writing, opened mines, and constructed aqueducts. The colony flourished rapidly, and accomplished the ruin of the formerly rich Orchomenos. Lastly, the myths tell of the doughty Sisyphus, who founded Corinth and established there the Semitic worship and Eastern civilization.
A lively activity went out from these and other colonists and colonies. Even the Semitic religion was partly accepted by the Greeks. The gloomy and repulsive service of Melkarth was always strange and abhorrent to them, but the worship of the fructifying Dionysus with its jolly festivals was warmly received. It entered into the life of the Hellenes and became national not only in the strongly Semitic islands, but everywhere on the Grecian mainland. The lascivious, mystic worship of the Semitic goddess of love, although humanized and beautified, was also one of the peculiarities of the Grecian people.
Notwithstanding this many-sided and powerful Semitic influence, which lasted for several centuries, the striving for national independence was strong even in the time of the earlier myths. Theseus, about a hundred years before the Trojan War, freed Athens from the island-chief Minos, to whom the state was then tributary. The Argonauts went out from Orchomenos and sought the distant metal-bearing land of Aja. The sons of the Argonauts besieged Troy, where they obtained treasures, the multitude and splendor of which astonished them. These were the first efforts of the Greeks to try their strength with the higher civilized Asiatics.
The great dispersion of the Grecian tribes took place in the succeeding times. The vigorous people spread on every side, and developed an unprecedented colonial activity. In the tenth and ninth centuries it settled numerous islands, and established a constant connection with the Asiatic mainland. The Milesians founded in the Pontus in the eighth century the city of Sinope, where they traded in iron and slaves, and Trapezium flourished in the ore-bearing country of the Chalybes. Syracuse, the metropolis of Italian Greece, was founded, and the colonization of Agrigentum from Rhodes followed. In the seventh century rose the cities of Selinus, Sybaris, and Croton. While the Corinthians were spreading out in the Mediterranean, the dominions of the Milesians were growing up on the Black Sea. In the sixth century, they had more than seventy colonies in those regions, and the productions of Colchis, of the Caucasus, and Armenia, of the Ural and the Danubian countries were flowing to them.
The ancient Oriental civilization, however, still long kept a prominent position by the side of these flourishing marts. Its influence on the development of Greece and of all the European peoples was deep and significant. As Roman civilization exercised a creative and shaping work long after the Germans had broken the power of the southern people, so also did Semitic civilization continue prominent among the Hellenic peoples long after the emancipation of the Greeks.
If we take the progress of the Greeks in metal-working especially into view, it reveals its dependence upon the Orient. According to their traditions, the Greeks received the processes of preparation and the applications of the metals from the Phrygians, but learned the higher technics of metal-work from the Phœnicians. Intercourse with the latter people also introduced the Oriental art forms to the West. All the productions of the earlier Grecian art bear an Oriental stamp; Mynias, who reigned in Orchomenos a generation before the Trojan War, was celebrated for his treasures of metals. He had an arched treasure-house, the walls of which were covered, after the Assyrian-Phœnician fashion, with plates of metal. He held intercourse with the Phœnicians, from whom he learned the art of building canals and irrigation. The treasury of Atreus, at Mycenæ, was likewise covered with metallic plates. Ulysses remarked the same style of ornamentation in the palace of Alcinous, where the walls were covered with plates of copper and the cornice was made of iron. In all of these cases we are informed from descriptions and from the latest excavations concerning the measure of Oriental influence in ancient Greece.
The useful metal in those times was almost exclusively the brown "chalkos." Of it consisted alike the finer wares which the Phœnicians introduced and the common fabrics which were imported from the neighboring islands, or were already made at home. It is significant of that early time that the smith was bluntly called "chalkeus"—copperer, or bronze-smith. The material, especially the home-made bronze, may not, it is true, have been of the best. The lances would bend, and the swords would break off at the handle. The better kinds of weapons, at least in Homer's time, seem to have been designated as "foreign," or as the gift of the gods. But after the dispersion of the Grecian tribes, following this period, a domestic industry of a better kind sprang up. The mines of Euboea were exploited; the copper-smiths of Delos furnished metallic chairs and beds; from Ægina came all kinds of bronze vessels, and thence originated also the first stamped money. Most important of all was the development of statue-casting, which was introduced in the fiftieth Olympiad, and quickly reached a high perfection. The Spartans had already in a former age built their temple of Minerva with its bronze reliefs, rich in figures. At a later period, every city had its statues of metal, and some cities, during the time of their vigor, had thousands of them.
While thus bronze served at first quite generally, afterward predominantly for artistic purposes, iron in the course of time came to the front as the useful metal. We have already mentioned that the weapons of ancient times were almost exclusively made of bronze. I now say, besides, that the Greeks were acquainted with iron even in the mythological period. Whether any of the Grecian tribes worked in iron of itself is, however, doubtful. The blacksmiths of Crete and Lemnos are described as Phrygians; and we know nothing more exact with reference to the origin of the Bœotians, who worked in iron in the most ancient times. We know, indeed, that they had trade relations with the Phœnicians, but this gives us no light respecting the iron art among them, for the Phœnicians of ancient times excelled only in bronze-working. It is also possible that they may have acquired some knowledge of metal-work in their Asiatic home. Whether this was the case, or the Bœotians learned to work in iron from the islanders, it is certain, first, that this primitive iron industry produced nothing of importance; and, second, that although foreign weapons of steel were known and famous, bronze still prevailed for a long period as the metal of use. Homer, indeed, speaks of an iron that the country-people used in covering their plowshares; he was likewise acquainted with the blue iron of which spear-heads were made, and with the tempering of steel; and excellent weapons of iron are described in the Iliad; but never, to my knowledge, is it mentioned that they knew how to make good steel weapons in Greece. The warriors were almost entirely armed with bronze, rarely with iron, and large articles of iron were very costly. It must not be concluded from this that small, simple vessels requiring neither a handsome shape nor a particular degree of hardness were not made out of native iron. In Homeric times, as I have said, plowshares were shod with a strip of iron of blacksmith's work. The iron reaping-hook came into use afterward. In Hesiod's time iron had gained the predominance over bronze among several tribes. I content myself with giving the history of metal-working in this single nation. With respect to the other European peoples we have a right to suppose that several of the tribes were acquainted with metallurgy in their original homes. They brought the knowledge of metals to Europe, which till then had been acquainted only with stone art. The greater number of the immigrants belonged to a lower grade of civilization, and the masses were still armed with weapons of stone; but among them were a few individuals or families who brought some skill in metal-work from their Asiatic homes. In the course of time the people who lived near these metal-workers obtained metals from them, and the further diffusion of those materials was promoted by trade and war.
The most favorable situation was that of the dwellers on the southern sea, who enjoyed the opportunities afforded by the Phœnicians trade. The ships of this people frequented the Black and Adriatic Seas, and the Spanish and Gallo-Britannic waters. Their goods were carried to the North by the inland routes. Foreign and domestic fabrics and shapes competed with each other over extensive districts; iron came in contact with bronze, and both materials crowded upon the hard stone weapons of the earlier time. Steel had gained the predominance over bronze in all Southern Europe in the time of the Romans, and the last remains of stone-age civilization in that part of the world were extinguished in the early middle ages. Thus the same cycle of technical changes was completed in Europe as in the East. Still, considerable differences may be observed in the course of development in the two cases. The metal-working age begins much later in the West than in the East, Semitic civilization attained its highest development under the predominance of bronze, while the higher intellectual life of the Europeans is accompanied by that iron-working art which now rules over the whole earth. Roman iron mastered the East; but it has gained immensely greater victories of peace in the Western world within a century through the agency of iron roads and wagons, swift steamers, and skillfully built and mighty engines.—Translated for the Popular Science Monthly from the Deutsche Rundschau.