THE USE OF COPPER AND BRONZE
Before we proceed we need to understand what the use of metal entailed. Copper was the first metal to be used in most parts of the world, followed by bronze, an alloy of copper with a low percentage of either arsenic, lead, or tin. The advantage of these metals is not necessarily that they are more resilient than stone, but that they can be melted and cast into a wide range of shapes and sizes of tools and weapons, with their working edges or points in the desired form. Bevelled-edge chisels in a range of sizes, toothed saws, adzes with sharp edges, and heavy-duty axes were tools possible or more effective in metal rather than stone. They made good tools for carpentry, for carving stones and ivory, for cutting shells or leather, and so on. In addition, copper is malleable, and can be beaten into thin sheets or vessels of the desired shape. This makes for very thin objects, not possible when copper is cast, and thus is an economical use of the metal.
Metallurgy was specialist work. Not everyone could recognize ores on the ground, or know their properties under heat, leave alone build and control the working of a kiln, using the best charcoal. It is possible that early metallurgy was a skill and lore passed down the generations among some small groups of people. These people would need to be mobile because the ores of copper, lead and tin are scarce and dispersed on the crust of the earth, and also because in their own tribes the scope for utilizing copper would have been limited.