In the early 20th century, many individuals - some undoubtedly well-meaning, others just plain hucksters - traveled the country selling their services as "rainmakers." The most famous of all was a plain-spoken, ex-sewing-machine-salesman named Charles Hatfield.

Hatfield claimed that evaporating certain chemicals into the air over periods of weeks or months could increase rain, sort of like applying fertilizer to fields. Despite many detractors - particularly U.S. Weather Bureau meteorologists - Hatfield built a reputation in the early 1900s, mostly through good luck and good public relations. Some newspapers even called him the "Wizard of Weather." His fame was assured in 1916 when San Diego hired him to help relieve a four-year drought. In the two weeks after he arrived, coincidentally, 38 inches of rain fell, a record that still stands.

Hatfield continued his exploits until the depression drove him out of business. Tomorrow night: did Charles Hatfield know something that nobody else knew, and what's the current research say about making rain?