ONE OF HISTORY'S GREAT intellectual adventures began on a summer day in 1799 when, near the Egyptian city of Rosetta, soldiers in Na- poleon's ranks found a slab of black basalt engraved in three languages. The stone's scripts--Greek, demotic (a simplified Egyptian script) and hieroglyphics--seemed to render the same message. If linguists could match the hieroglyphs to the Greek, all of Egyptian literature would be theirs.

It took until 1822 for Jean-Francois Champollion to discover that hieroglyphics mixed phonetic and symbolic meanings; that some texts should be read right to left, others left to right or top to bottom; and that some symbols had two different meanings. This breakthrough, and the translations it produced, led to revelations both humbling and exhilarating: The Egyptians knew medicine, astronomy, geometry. They used weights and measures and had an organized system of government. They were passionate, too: "Your voice is like pomegranate wine," ran one poem.