Polonium were marketed by Firestone from 1940 to 1953. While the amount of radiation from the plugs was minuscule and not a threat to the consumer, the benefits of such plugs quickly diminished after approximately a month because of polonium's short half-life and because buildup on the conductors would block the radiation that improved engine performance. (The premise behind the polonium spark plug, as well as Alfred Matthew Hubbard's prototype radium plug that preceded it, was that the radiation would improve ionization of the fuel in the cylinder and thus allow the motor to fire more quickly and efficiently.) Polonium is
Discover Financial and U.S. Bank. In addition to its card products, Discover also markets savings products, checking accounts, personal loans, student loans, and home equity loans. Discover Financial Discover Financial Services, Inc. is an American financial services company that owns and operates Discover Bank, which offers checking and savings accounts and credit cards. It also owns and operates the Discover and Pulse networks, and owns Diners Club International. Discover Card is the third largest credit card brand in the United States, when measured by cards in force, with nearly 50 million cardholders. Discover is currently headquartered in the Chicago suburb of Riverwoods,