Last night I related the story of Charles Hatfield, who achieved fame in the early 20th century as a rainmaker. Even at that time, scientists knew that Hatfield's methods didn't enhance the rain - his claimed successes relied mainly on good showmanship, a gullible audience, and remarkable coincidence.

But at that time, public relations, not science, carried the day. Years later, Burt Lancaster played a character resembling Charles Hatfield in the 1956 movie "The Rainmaker," based on a play of the same name.

Today, the manipulation of rain clouds that Charles Hatfield claimed eludes even the most advanced scientists in the field of weather modification. Modern researchers do "seed" clouds with various small solid particles that, in principle, can act as nuclei for clouds to grow. However, experimental tests have not yet shown that these methods actually increase rainfall. Today, cloud seeding remains a promising, yet unproven, area of active research.