***** purely conceptual design of the principle ***** the H-bomb is illustrated here. The ordinary hydrogen and rare tritium are kept in a liquid state in separate containers cooled by means of a special refrigerating system or cryogenic apparatus. On either side of the hydrogen containers but separated by an insulator and rigid tamper are two targets of uranium-235. Each lump of U-235 rests at the end of a massive gun barrel imbedded in an even more massive tamper. Each gun barrel also contains