225. The Bronze Age: Copper and Bronze Phases
There is no abrupt break between the Neolithic and the Bronze Age. Metal was at first too rare, too difficult to mine and smelt and work, to be used extensively. It served for special weapons, tools, and ornaments of the wealthy. The life of the mass of the population went on in much the old channels for generations or centuries after the new material had become known. This was true especially of peoples in oreless regions, or too backward to have learned the art of metal working. To such nations, the first bronze came as an imported rarity, to be guarded as a treasure or heirloom.
Of even less immediate effect than the discovery of bronze, was that of the first metals known, copper and gold. The latter is of course too scarce and too soft to serve for anything but ornaments; and pure copper also, even when hardened by hammering, is of little use for many mechanical purposes. It makes a fairly efficient dagger, a rather mediocre ax, and a poor knife. The result was that a recognizable period of copper preceded the true Bronze Age, yet that it was essentially a last phase of the New Stone Age, with the metal creeping in as something subsidiary. In Italy and Spain it has therefore become customary among archæologists to speak of an “Eneolithic” period as a transition stage in which some copper, and occasionally bronze of low tin content, occur. In central and northern Europe, the equivalent stage falls somewhat later and is sometimes called the Stone-Bronze period.
Bronze is an alloy of tin with copper, harder than the latter, easier to melt, and casting better. In many properties it resembles brass, by which term it is referred to in the English Bible; but must not be confounded with it. Brass is an alloy of zinc with copper, of much later discovery, apparently in Asia, and until recent centuries little used in Europe. As regards bronze, even a two per cent addition of tin to copper results in a perceptible hardening; and five to ten per cent produce a greatly superior tool metal.
The origin of bronze is a problem of some difficulty, because the earliest known users of bronze, the peoples of the Near East, possessed little or no tin. There are said to have been tin supplies in the Khorasan district of Persia, which might have been drawn upon by the pre-Babylonians and thence carried to Egypt. The chief source of the tin of later antiquity was Spain and England. But at the outset of the Bronze Age, the Orientals did not even know of the existence of these countries, while their natives, still ignorant of copper, could not have mined tin for the purpose of hardening that basic metal.
Just how, then, bronze was discovered, is still unknown; but it must have been in Western Asia not later than the fourth millenium B.C. Before 3000 B.C., in the period of the first dynasties ruling over united Egypt, the art had been established in that country, since bronzes low in percentage of tin have been discovered from that era. While ancient Egypt mined its own copper in the adjacent Sinai peninsula, it is barren of tin resources, so that the latter metal must have been imported. Within a few centuries, bronze began to be used in Crete and Troy, and by 2500 B.C. in Italy and Spain, whereas it did not penetrate central and northern Europe until about 1900 B.C., according to the usual estimates. That the use of bronze over these widespread areas is a connected phenomenon, a case of single origin and diffusion, is clear from the manner in which the art spread from its center of invention like a wave which arrived later the farther it had to travel. The spread is confirmed by the fact that certain implement forms such as early triangular daggers and later swords traveled with the material. Had the western natives discovered bronze for themselves, they would have cast it into shapes peculiar to themselves, instead of adopting those long established among the Orientals.