Bronze alloy

   The alloy called bronze is a mixture of copper and tin. Bronze has been used for at least 5,000 years—much longer than iron.
   People of the Old Stone Age used tools and weapons made of stone. In the New Stone Age they had much better stone weapons. When copper was discovered, our early ancestors began making tools of copper. But copper was not hard enough to take the place of stone entirely.
   Probably bronze was first made by accident. Some rocks have in them both copper ore and tin ore. When early man discovered bronze, he found it was much harder than copper. Early man learned to use bronze for tools and weapons. Later it was found that iron made even better tools and weapons. Iron gradually took the place of bronze.
   The time when people used bronze for tools and weapons is called the Bronze Age. The Bronze Age came at different times in different parts of the world. The early civilizations of the Near East were in their Bronze Age more than 4,000 years ago. The Indians of South America were still in their Bronze Age when Columbus reached the New World more than 500 years ago.
   Today many beautiful bowls and statues and doors are made of bronze. Much hardware is made of it. Bronze is used in bells, too. One big use of bronze in the United States is for pennies.
   Things made of bronze last for a very long time. Bronze can stand heat and cold, wind and rain, and much handling. It lasts so well that it is sometimes called the "eternal metal."