Scientists are unsure as to when it was discovered that coal could provide heat when burned; however, coal has probably been used as a fuel since prehistoric times. The ancient Chinese mined coal hundreds of years before the Christian era, and developed the world's first coal industry around 300 A.D., when they began using coal from shallow deposits for heating buildings and producing metals. By 1000 A.D., coal had begun to replace charcoal--which is made from wood--as the leading fuel in China. One of the earliest records of coal's economic value appears in a poem written by Shen Kua, a Chinese scientist of that era.

In Europe, coal was mined in Germany about 1,000 years ago. During the 1200s, coal was produced commercially from open pits in England and Belgium. Mainly, it was used for smelting and forging metals; blacksmiths, for example, took advantage of coal's hot flame to...