Ideas: A History from Fire to Freud

By placing the invention of two-tiered pottery kilns – towards the end of the fifth millennium – next to the archaeological observation that certain copper objects were discovered at Susa, Al ‘Ubaid, Nineveh and Ur, we can conclude that smelting was discovered about 4300 BC. We know that by 4000 BC knowledge of the process had spread to a number of regions in western Asia and that, by 3800 BC, copper smelting was being practised ‘comparatively widely’ in the ancient world.⁶⁵ ‘By the early years of the third millennium BC, the people of Sumer had created the first important civilisation known to us in which metals played a conspicuous role.’ (The oldest known stock of metal tools dates from 2900 BC.) From these dates onward copper was the dominant metal in western Asia and north Africa until after 2000 BC.⁶⁶

Insofar as early metallurgy was concerned, after the discovery of smelting two advances were crucial. These were the discovery first of bronze and second of iron. There are two mysteries surrounding the advent of the Bronze Age, certainly so far as the Middle East is concerned, where it occurred first. One mystery lies in the fact that tin, the alloy with copper that makes it much harder, as bronze, is relatively rare in nature. How did this particular alloy, therefore, come to be made for the first time? And second, why, despite this, were advances so rapid, with the result that, between about 3000 BC and 2600 BC, all the important advances in metallurgical history, save for the hardening of steel, were introduced?⁶⁷

In one sense, we should call the early Bronze Age the alloy age. This is because for many years, either side of 2000 BC, and despite what was said above, objects that might be called bronze had a very varied chemical make-up. Alloyed with copper, and ranging from less than 1 per cent to 15 per cent, there could be found tin, lead, iron and arsenic, suggesting that although early man had some idea of what made copper harder, more malleable and gave its tools and weapons a better edge, he wasn’t entirely comfortable with the precise details of the process. The exact composition of bronze also varied from area to area – between Cyprus, Sumer and Crete, for example. The all-important change-over from copper to real bronze occurred in the first quarter of the second millennium BC. ‘Tin differs from copper – and the precious metals – in that it is never found in nature in a pure state. Instead, it is always in chemical combination. It must therefore have been smelted, though (and this is another mystery) hardly any metallic tin has ever been found in excavations by archaeologists. (In fact, only one piece of pure tin older than 1500 BC has ever been found.)’⁶⁸

Though the exact origins of bronze are obscure, its attractions over copper were real enough, once its method of production could be stabilised, and its increasing popularity brought about considerable changes in the economy of the ancient world. Whereas copper was found in a fairly large number of localities, this was not the case with bronze for, as was said above, in neither Asia nor Europe is tin ore widely distributed. This limitation meant that the places where tin was mined grew considerably in importance and, since they were situated almost entirely in Europe, that continent had advantages denied to Asia and Africa. The fact that bronze was much more fluid than copper made it far more suitable for casting while its widespread use in weapons and tools simply reflects the fact that, provided tin content could be kept at 9–10 per cent, hammered bronze is usually a good 70 per cent stronger than hammered copper. The edges of bronze tools were at least twice as hard as copper.⁶⁹

This final fact about bronze was very important. The sheer hardness of bronze meant that the edges of daggers became as important as their points, encouraging the development of swords. Moreover, this development coincided with the domestication of the horse in the steppe countries of Europe, and the wheel in Sumer. Warfare was therefore suddenly transformed – in fact, it changed more rapidly than at any other time until gunpowder was used in anger in China in the tenth century AD.⁷⁰

The Bronze Age reached its peak around 1400 BC. It was a time when iron was scarce and valuable. Tutankhamun reigned for only a very few years as a pharaoh in Egypt, and died about 1350 BC, but his tomb, famously discovered and excavated by Lord Carnarvon and Howard Carter in 1922, contained – besides vast quantities of gold, jewels and fabulous ornaments – a dagger, headrest and bracelet all made of iron.⁷¹ There were also some very small models of tools, barely an inch long, also made of iron. In all cases this was smelted iron, not meteoric.