Like many inventors, Lee De Forest was a brilliant innovator but a poor businessman; he spent much of his life fighting lawsuits and lost as many fortunes as he made. A prolific inventor, De Forest had more than 300 patents to his credit. He worked in a host of areas including radar, diathermy (application of alternating current to the body in medicine), telephone, and color television. But his most important achievement was his audion, an electronic device that helped launch a century of innovation in electronics. De Forest was born at Council Bluffs, Iowa, on August 26, 1873. His father was a minister whose interest in astronomy may have sparked his son's love for science. De Forest attended Yale University, studying under Josiah Willard Gibbs (1839-1903), a pioneer in the disciplines of physical chemistry and advanced thermodynamics. De Forest's 1899 Ph.D. dissertation, on the reflection of "Hertzian" (or radio) waves, was...