Polonium Radioactive Electrode Firestone Spark Plug

This is a vintage Firestone Spark Plug with a Polonium "Radioactive" Electrode in its original box. First that are entirely safe since they were alpha particle emitters when made which do not penetrate the skin and the source has a half like of 138 days. About 65 years later, they no longer emit. The idea to incorporate radioactive material into spark plugs seems to belong to Alfred Hubbard who received a patent for this concept in 1929. The Firestone Tire and Rubber Company was, I believe, the only company to actually market the idea. The first commercially available spark plugs became available in 1940. Polonium-210 was incorporated into the electrodes that formed the spark-gap of the spark plug. More specifically, the polonium was added to the molten metal (a nickel alloy) from which the wires that were used to produce the electrodes were drawn. The alpha particles emitted by the decay of the polonium would ionize the gas within the spark gap and this would presumably result in a longer and/or fatter spark. The November 1941 issue of the Science Digest reported that tests had indicated that �30 percent fewer revolutions were required to start the motor as compared with other spark plugs. According to the company's advertising, the spark plugs resulted in a smoother motor performance . . . faster pick-up . . . quicker starting ... read more