The term bronze (Greek: chalkos; Latin: aes) refers to an alloy of Copper and Tin. In antiquity, besides the two principal components, the compound sometimes also included trace amounts of other materials, including arsenic, nickel, gold, silver, zinc, and Lead. Proportions of the two primary ingredients as well as the additional elements could be manipulated to achieve a number of different aesthetic and functional effects. The alloy of copper and zinc known commonly as Brass was not developed and used commonly in the ancient Mediterranean until at least the late first century BCE.
The technology required to mine and process copper ore seems to have been known as early as the fifth millennium in the metallurgically rich regions of eastern Anatolia and Mesopotamia. The earliest archaeological remains of a true bronze compound, although relatively low in tin content at first, have been dated to the fourth millennium in both the Near East and Egypt. By the third millennium, bronze was used widely throughout the ancient Mediterranean for tools, weapons, household objects, vessels of various shapes, and small-scale decorative objects.
Although copper can be hammered, shaped, and cast on its own, the addition of tin has multiple advantages, including a lower melting point, a more malleable material, and a stronger, more durable finished product. The normal ratio of copper to tin was approximately 9:1. Compounds with more than 10 percent tin tend to become more brittle and difficult to work. Independently, copper has a reddish tone but a tin-bronze alloy has a golden appearance. Proportions could be varied and small amounts of different elements could be introduced. The addition of lead, for instance, resulted in a very stable, though heavy, product that was desirable for the rims, handles, and feet intended for attachment to vessels. For all of these reasons, it is not surprising that bronze alloys eclipsed the use of copper alone almost entirely after their introduction.
Pliny writes in his Natural History (34.3) of particularly renowned manufacturing centers such as Corinth, where particular proportions of materials produced finely colored bronzes, but it is difficult for us today to discern where objects were made on the basis of appearance or material analysis.
Beginning in the third millennium, bronze was the single most important material for producing tools, weapons, armor, household objects such as furniture fittings, chests and boxes, vessels of various shapes, small-denomination coinage (see Bronze coinage), and decorative objects of all kinds, from large-scale sculpture to small figurines and musical instruments. Following the decline of the Greek economy at the end of the Mycenaean period there was a period of widespread depression in overseas trade and exchange, during which it was difficult to obtain the raw materials necessary for the bronze alloy. Production, therefore, slowed between the late thirteenth century BCE and the dawn of the first millennium; craftsmanship also seems to have declined. By at least the ninth century, however, Greek bronze workers once again were making vessels, arms, armor, tools, and a host of other implements on both small and large scales. Even after the development of iron-working techniques in the first millennium, bronze remained a manufacturing staple throughout the Roman period.
Although today most ancient bronzes have a green or blue patina, they originally would have been polished to a golden shine. The material had the advantage of being attractive and strong for a wide array of uses but much less expensive and easier to obtain than its precious metal counterparts of Gold and Silver.
The development and use of bronze alloys across a wide geographic area represents an important step in both technological and economic arenas. Copper could be mined throughout Mesopotamia, Egypt, and the Mediterranean, particularly in Cyprus, but tin was less readily available. It could be found in the east, in Anatolia, and in the west, in the British Isles. Herodotus, a fifth-century Greek historian, refers (3.115) to the British Isles as the "isles of tin." The Greeks, therefore, had to participate in far-reaching international communications and trade in order to obtain the basic materials necessary for the bronze they used ubiquitously. The sea routes and overland paths established in pursuit of tin likely played a major role in their colonization efforts, particularly in the west, after the eighth century BCE.
Several different bronze-working techniques were used in antiquity. The simplest and earliest alternated heating, hammering, and cooling to raise a thin, flattened sheet of metal to the desired shape. Alternatively, objects could be cast, either solid (especially for smaller implements and parts destined for attachment, such as the handles and feet of vessels) or hollow. The last of these approaches was the most complex and last to develop. In the lost-wax method, a wax model was created in the form of the desired object and then covered in clay. When the clay was fired in the kiln, the wax melted out, forming a hollow shell into which molten bronze could be poured. Once the metal cooled, the outer clay mold was removed. Because it began with a mold that was not destroyed in the firing, it also had the distinct advantage of being re-usable and well-suited for the production of multiples. Post-firing, craftsmen removed blemishes, polished the surfaces, and added decorative details in cold-work. Other refinements, such as silver accents or stone inlays, could also be added in the last stage of production. Before the late sixth or early fifth century, rivets and pins were used to mechanically fasten the cast parts together; later, lead solder often was used to join separately cast pieces.
The quantity of bronze implements that survive from the ancient world pales in comparison to what once existed. Unlike terracotta and other organic materials, bronze could be reused in cases of disrepair and also in times of need, for instance, for coinage or military equipment. Archaeologically, bronzes are found most often in burial contexts, where they were protected from both the melting pot and damaging environmental elements. Hidden hoards of bronze and other metallic objects, once stored for safekeeping and never reclaimed, are discovered infrequently. Even in the best of conditions, often, the delicately hammered bodies of helmets, shields, vessels, and statues have deteriorated over time; solid-cast attachments and smaller objects have fared better.
Colonization, Greek; Cyprus; Iron; Metallurgy; Metalwork, Byzantine.
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