Lee de Forest served as a faculty member at Armour Institute of Technology and Lewis Institute during the turn of the twentieth century. During that time he conducted his first long-distance broadcasts from the roof of Main Building. He invented the Audion three-element vacuum tube; the resulting tube amplified electric signals and served as a fast-switching element that later would be used in digital electronics. De Forest also patented a method of recording sound on film that the movie industry would later adopt. He received an honorary Oscar, was given a star on the Hollywood Walk of Fame, and was inducted posthumously into the National Radio Hall of Fame.