One of his longtime pet projects was an environmentally friendly heat pump that used water instead of Freon. Johnson finally completed a prototype one night in 1982 and decided to test it in his bathroom. He aimed the nozzle into his bathtub, pulled the lever and blasted a powerful stream of water straight into the tub. Johnson’s instantaneous and instinctive reaction, since shared by millions of kids around the world. In 1989, after another seven years of tinkering and tireless sales-pitching, during which he quit the Air Force to go into business for himself.