SWEDEN. Alfred Nobel/50th Anniversary of the Invention of "Extra Dynamite" Uniface Bronze Plaque, 1929. MINT STATE.

Dimensions: 41x59mm; Weight: 57.25 gms. By Sporrong & Co. Obverse: Bust of Nobel left; in four lines below: NOBELS / EXTRADYNAMIT / 1879-1929 / NITROGLYCERIN - A.B.; Reverse: Blank. Edge: Plain. Brown-bronze surfaces, with a delightful matte nature. In addition to his discovery of dynamite, Nobel also invented a slightly safer (and cheaper) alternative in 1879 which he dubbed "extradynamit."