For each of ten patents from radio history, a background essay is given, with a reproduction of the patent specification and a list of sources for further information. Includes Heaviside's coaxial cable, Edison's electrical indicator, Lodge's tuning patent, Fessenden's heterodyne, Marconi's radio telegraphy, Fleming's diode, de Forest's triode, Conrad's Aeriola Junior and Armstrong's superheterodyne and FM patents.