Jim Kelly, age 10, of Peoria, I11., for his question:

WHEN WAS THE IRON AGE?

Experts usually divide human history in two main parts. Recorded history began 6,000 years ago, when people learned to write down the events of their times. The long ages before the invention of writing are called prehistory, and sorting it out is a major problem. The Bronze Age and the Iron Age began in these prehistoric times.

The story of prehistory goes back to cave man days, when our human ancestors were hunters. They sheltered themselves in natural caves and under rocky ledges. They gathered seeds and threw stones at passing animals to get meat. Gradually they learned to chip stones to make scrapers, hammers and other useful tools and weapons.

These were the Paleolithic people of the Old Stone Age. Sometime during this long chapter of prehistory, people learned to control and use fire.  There were many groups of Old Stone Agers, and each group discovered fire in its own time. Their simple campfires were used to cook meat, to provide heat and scare off hungry animals.

The Old Stone Age ended when the groups gave up wandering and settled down. They left the old caves and built homes of some sort. They became shepherds and farmers, learned to make baskets, cooking pots and woven cloth. Their first tools and weapons were made of stone, so we call them the Neolithic, or New Stone Age, people.

Some of the New Stone Agers learned to heat and mold lumps of copper and tin. Later they melted these two metals together to make hard, durable bronze. In most groups, the Bronze Age began about 5,000 years ago. It lasted until metal workers melted and hammered fallen meteorites to shape even tougher tools and weapons.

The meteorites were made mostly of iron. And in time, the early metal workers learned how to smelt iron from certain rocky ores. This chapter of the prehistory was the Iron Age, and among most early societies it began about 1100 B.C., more than 3,000 years ago.

The two Stone Ages, the Bronze Age and the Iron Age are named for the materials that people used to make most of their tools and weapons. Nowadays, our most popular metal is steel, which is a refined form of iron. This is why some people claim that we are still living in the Iron Age of human history.