We love dividing the world up into threes: animal, vegetable and mineral; mind, body and spirit; past, present and future; starter, entree and dessert. And so it was 200 years ago, when the curator of what was to become the National Museum of Denmark, Christian Thomsen, gave us the Stone Age, the Bronze Age and the Iron Age. Within a couple of decades, despite its many flaws, Thomsen's tripartite division of history was adopted by European archaeologists to the extent that it still persists even today — you probably learned it at school. It's still handy, if somewhat inaccurate, to talk of the Late Stone Age and the Bronze Age Collapse.
Inasmuch as the system is useful, it's the Bronze Age that warrants our attention, for it was the serendipitous discovery of bronze — at least in Europe and the Middle East — that changed everything. (In some other parts of the world, like sub-Saharan Africa, civilizations essentially skipped bronze and went straight from stone to iron.) For some 3 million years prior, early humans had chipped and flaked stone cobbles and flint shards to make crude hammers and cutting edges, with little sign of improvement from one generation to the next. But once our ancestors figured out bronze, exponential progress followed.
Bronze wasn't the first metal to be utilized for tools by our forebearers; copper has that distinction. (Previously, native gold and meteoric iron had only been used for jewelery.) I wrote about Ötzi-the-Iceman's 99.7 percent pure copper ax head here some weeks ago ("Ötzi the Iceman," Aug. 10). Copper, usually in the form of an ore but sometimes as a pure metal, is quite common; it's found in Earth's crust at a concentration of about 70 parts per million. (Compare that to ubiquitous iron and rare tin at concentrations of 50,000 and two parts per million respectively.) Ötzi died about 5,300 years ago, while the first evidence for copper smelting (heating ore to extract metal) dates to about 7,000 years ago. This ushered in the Chalcolithic Age, or Copper Age, which didn't make Thomsen's classification, and that period now is usually considered to belong to the Neolithic or New Stone Age. The problem with copper is that it's soft. Ötzi couldn't have downed a small tree without repeatedly sharpening his ax.
Bronze is what you get when you combine copper with either arsenic or tin in a roughly 10-1 ratio. It's that addition that makes all the difference: Bronze is much harder and more durable than copper. For 2,000 years, from about 3300 to 1300 B.C., bronze was king in Europe and the Middle East, used for practically everything, including weapons, armor, agricultural tools, domestic items for cooking and sewing, mirrors, coinage and sculptures.
"The Lady of Kalymnos" is an intriguing example of the latter. In 1994, a Greek fisherman found the larger-than-life bronze figure between the islands of Kalymnos and Pserimos in 300 feet of water, where she'd probably lain for 2,000 years. She had been cast in bronze, probably in the second or third century B.C., and may have been en route to Rome when the ship in which she was being transported foundered. Notice her excellent state of preservation, thanks to bronze's property of resisting corrosion, even in seawater.
Next week, we'll look at how bronze may have originally been discovered and how its large-scale manufacture changed the ancient world.
Barry Evans (firstname.lastname@example.org) just spent an hour with the Lady of Kalymnos trying to figure out what her raised hand is warning us about.