Copper Ingot resulting from smelting with ancient Technologies (except the Hammer !)
A few weeks ago, I wondered whether the first maritime trading system in the Eastern Mediterranean Basin was a consequence of the discovery of copper. For almost two thousand years, copper was the only metal that human beings were able to process. Until some smart person figured out that adding 10% of tin - melting at a lower temperature -created a much harder metal: bronze. Ancient tin mines were found in the Taurus Mountains of Anatolia, not far from Cyprus, the copper island.
Copper Slack found at Dromolaxia (Hala Sultan Tekke), an ancient Cypriote Town
Did copper have an impact far beyond? From the slack of antique copper mines on Cyprus we know that the island produced about 200’000 tons. Not a big number today. But for antiquity it was huge. This must have been quite an effort. Am trying to list the number of activities - or division of labour - necessary to support mining on such a scale:
Loggers and Charcoal Burners: The melting temperature of copper is 1’084 degrees Celsius. Such temperatures can only be reached and maintained by using charcoal and bellows. A normal wood fire gets up to 600 degree – not enough for sustained production. Smelting 1 kg of copper requires 300 kg of charcoal (25% weight of wood). An entire tree of more than 1 ton was necessary for 1 kg of copper. In my previous blog I estimated that 65 tons of copper were annually produced on Cyprus. Loggers had to fell 65’000 big trees. I guess with copper axes and copper saws. Cooking charcoal is a delicate business and requires a high level of skills if yields of 90% were to be achieved. Charcoal burning too became a profession.
Cooking Charcoal in Slovenia today is not much different from Antiquity
Carpenters: Probably related to loggers. Mines need shaft support and cranes. Wooden beams were the only material available. Cedar logs had to be sawn into regular beams, holes to be drilled to join them with wooden nails. The same holds true for building cranes which operated with wheels. Rope-makers were also needed. I have no data to quantify carpenter work. But both activities require special skills. I guess these activities became professionalised early. Needless to say that ship building requires the same skills. Maybe the professionalisation started with building boats first and was then transferred to mining activities
Copper Axes were less heave than Stone Axes and easier to sharpen
Basket Weavers: The average copper content in Cyprus ranges from 0.5 to 4.5% of ore. 40 kilos had to be brought to the surface to make 1 kg of pure copper. How did they do this? Probably with bags slung over their shoulders and woven baskets. Am pretty sure the miners did not make these themselves and that a cottage industry developed where textiles for bags and baskets were woven. To make 65 tons of copper, 2’600 tons of ore had to be lifted = 65’000 baskets at 40 kg each. Assuming a basket lasted for a month before breaking, 5’500 had to be made.
Ancient Egyptian Basket made from Reeds - now in the British Museum
Smelting and Casting: Copper was smelted in purpose-built clay kilns, a technique probably developed in Mesopotamia. If you are interested there are a number of videos on YouTube to watch. The process was very time consuming. For every round, a new kiln had to be built. One round of smelting would result in a few ingots of pure copper – not more. They had to be purified from slack. Then melted again to be cast into the 20 – 30 kilo Oxhide shapes – the form in which they were traded.
Copper Smelting using ancient techniques - watch the Video on YouTube
Metal Workers: A 20 kg copper Oxhide is not a product you can use. Some one has to turn it into axes, spears, arrow heads, saws, pots and jewelry. Knowing how to melt copper was a prerequisite for this activity but you need to know how to make casts, how the metal behaves when cooling, how to hammer it into shape, how to add ornaments. It is a business by itself. Human Beings know how to make copper beads for more than 13’000 years. Thousands were found in Eastern Anatolia at the Boncuklu Teppe site, just north of the Syrian border. But making copper vessels or copper helmets required a far higher degree of sophistication.
Because of its Heat conducting Property, Copper has many Uses in the Kitchen
Accountants: Since extraction of copper has a long value chain, somehow people had to track it to reward the various contributors. Without numbers and some form of book keeping, this is impossible. We know the first number systems started in Mesopotamia in 3'500 BC. Is it a coincidence that numbers appeared at about the same time as copper? Without keeping track of production, accounting for sales and standard weights, how could copper have been priced and traded?
We still use the Mesopotamian Number System to keep Track of Time
I believe that the discovery of copper and the development of skills to produce it on a large scale played an important role in the development of civilisation. To get copper, people had to adopt the division of labour. Society had to be re-arranged. I was not surprised when research papers on ancient Cypriote copper towns showed a high degree of specialisation. It makes perfect sense to concentrate skills in a hub or a cluster. It also would not surprise me if copper played an important role in the stratification of societies. Copper was the first fungible material to store value. It was used for payments, as tools (the famous Alpine Man Ötzi carried a copper ax), for weapons making, household goods and decorative jewellery. Since it could be melted and re-casted for new purposes, copper had strategic value.
The Ancient Cypriote Copper Town Dromolaxia next to the Mosque of Hala Sultan Tekke
Have never found a paper on the role of metal in the development of civilisation but it could be worthwhile pursuing this idea further.