The Iron Age

      The first metals discovered by ancient man were gold and iron. Gold because it can be found in its pure form at the bottom of streams, and iron in its pure form (or mixed with nickel) from meteorites. Gold, being soft, has never had a practical use except as jewelry, ornaments, or decoration, though eventually its best use will be to become a form of common currency.

Iron in its pure form was simply a novelty. No ancient people had a source of heat (1528 degrees Centigrade) that would melt it, in order to form it into something useful. How many meteorites have you collected?

The first practical metal was copper. And it was discovered to be a useful product only when early man began to make pottery. A furnace made to harden clay pots will get hot enough (1083 degrees Centigrade) to melt copper from its ore, and so copper was no doubt found by potters among the stones in the furnace taken to that temperature. One of them - we don't know his name and he didn't get a patent - decided to heat up the irregular fragments and as a result, obtained a single large lump of it. We don't know who but we know where and when: Anatolia, about 7,000 BC.

From there it was a smaller leap to pouring the molten copper into a mold to make a useful tool. A sword, or a plowshare.

We identify the levels of civilization based on when such discoveries become available in different parts of the world. We call those levels The Stone Age, The Bronze Age, The Iron Age. If our historical map included "The Copper Age", it would be inserted between Stone and Bronze, because you need to know about copper before you discover bronze.

There are five ores which contain copper, the most common being azurite and malachite. From 4000 BC, actual mining for ores begins, rather than just picking up the stuff from the ground. This appears to occur first in the Balkans.

Ore which contains copper may also have tin, and the next intellectual step is when someone notices that the molten material in the furnace does not have the right "copper" color. When tin and copper melt together they form a material harder than either, which takes a sharper edge than either and lasts longer. It is called bronze, and it will be the first "alloy". Historians say this discovery was made at Sumer, about 2800 BC. The discovery would spread outward, reaching Europe and China about the same time, 2000 BC.

But tin is scarce compared to copper, and bronze articles begin to diminish (in the archeology record) around 1800 BC as the supply of tin reaches exhaustion in the Middle East. Various cultures will attack each other for the singular purpose of obtaining bronze. However, large quantities of tin will be discovered in Cornwall, and "Breton" will become a major supplier.

The Bronze Age will appear at different times among different peoples, different cultures. Thus the Bronze Age is not uniform around the world, nor will any of the other - and later - "ages" be uniformly distributed, in time or place.

Iron ore is plentiful and therefore cheap. But the temperature to melt it (1,528 degrees Centigrade) is beyond the ability of any ancient furnace. When furnaces get that high, the metal will melt together with a sludge of impurities, and the result is not useful. The impurities must be beaten out - literally. (The anvil appears.) And the process must be repeated: heat, pound, heat, pound. Such good iron appears, first as weapons, in Anatolia, about 1500 BC. This iron is not as hard as bronze, but no tin is required, and the iron ore is everywhere you look. Farm implements, weapons, and armor will now be made in iron. "The Iron Age" has begun. For the warrior class, iron weapons and armor will overwhelm the opposition carrying "last year's" technology.

About 1,100 BC, someone discovers that if, in the reheat, pound process, charcoal (carbon) is mixed in, and then the heated iron is plunged into cold water, the iron will be harder than bronze. This will be called steel. It will make the best of weapons for centuries to come.

In 513 BC the Chinese will develop a blast furnace which can melt iron out of its ore with no impurities. This will allow the Chinese to pour the molten product directly into molds, permitting them to cast ("cast iron") the likes of pillars and other structural pieces for multi-story buildings. It will take at least another thousand years before such a furnace will appear elsewhere in the world.

Leap forward now to 1709 AD. An English ironworker discovers that coke (plentiful) can replace charcoal (expensive) in making steel. Soon large structures in iron will replace older materials: iron bridges will span rivers, and far outlast timber.

There are 86 chemical elements known as "metals" today. Only seven were known to the ancients: the ones we have mentioned (gold, copper, tin, and iron, but not bronze or steel as they are alloys) plus mercury, silver, and lead. Zinc would be discovered later, and when combined with copper, would produce a new alloy - Brass! Hey, this stuff looks like gold, but harder!

The Iron Age never appeared in the Western Hemisphere. When Europeans arrived, they found the native tribes using copper implements. But even more surprising is that the most important invention of all early peoples was the wheel. The Aztecs, Inca, and Maya, in several ways, reached a "high" culture (and some very low points as well), but the wheel never appeared in the Western Hemisphere until the European arrived.

So, the "Iron Age" means this: it is that time in history when a group of people, or a culture, if you will, obtains the knowledge to forge iron. The discovery may be due to a single individual, a name lost to history. And then carried, as knowledge, to other parts of the world. Or in places far apart, more than one person, in his own neighborhood, may have made this discovery without foreign knowledge. We will never know. But we do know that it is a Step in the technology continuum, in which a population embraces all the previous steps, the previous discoveries.

There have been various names for "ages" after the Iron Age, but none of them have a metal in the title. Yet there would be several metals that, when discovered and implemented, would establish a new leap in technological sophistication. Think of: platinum, aluminum, plutonium, magnesium, radium, titanium, chromium, cobalt, tungsten.

And uranium.

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