When members of the Chicago Commercial Club arrived to hear a lecture by the famed electrical inventor Nikola Tesla on May 13, 1899, they were startled by the sight of an artificial lake sitting in the middle of the auditorium. Everyone knew that Tesla--the man who had devised the alternating-current (AC) system that brought electricity into people's homes and businesses--was a master showman. Six years earlier at Chicago's Columbian Exposition, for example, the dapper engineer had dazzled spectators by sending 250,000-volt shocks coursing through his body. Now the audience was abuzz, wondering what Tesla was going to do with his miniature lake and the six-foot boat that floated on its surface.

Abruptly, the craft began to motor around the pool on its own, with lights blinking. From the side, Tesla operated a remote-control unit that conveyed commands to the boat via invisible radio waves. The crowd was astonished. He then invited individuals to shout out commands: "Turn left! Flash the lights!" Using his wireless transmitter, Tesla signaled the boat, and it executed the requested maneuvers. With the Spanish-American War having just come to an end, the audience was impressed by Tesla's proposal to arm a larger vessel with dynamite and then steer it by remote control toward an enemy naval ship. Here, more than a century ago, was a prototype for the guided missile.