James Cook Medal, undated, bronze, plain edge (Betts-553), 547.7 grains, obv., IAC COOK OCEANI INVESTIGATOR ACACERRIMVS (James Cook, the most ardent explorer of the ocean), around bust of Cook to left, REG.SOC.LOND.SOCIO SVO (The Royal Society of London to their Fellow) in small letters below bust, rev., NIL INTENTATVM NOSTRI LIQVERE (our associated leave nothing untried), around representation of Fortune, standing, wih globe, spear, and other accoutrements, AVSPICIIS GEORGII III in small letters below, Proof, splashes of red in recessed design areas

Details
James Cook Medal, undated, bronze, plain edge (Betts-553), 547.7 grains, obv., IAC COOK OCEANI INVESTIGATOR ACACERRIMVS (James Cook, the most ardent explorer of the ocean), around bust of Cook to left, REG.SOC.LOND.SOCIO SVO (The Royal Society of London to their Fellow) in small letters below bust, rev., NIL INTENTATVM NOSTRI LIQVERE (our associated leave nothing untried), around representation of Fortune, standing, wih globe, spear, and other accoutrements, AVSPICIIS GEORGII III in small letters below, Proof, splashes of red in recessed design areas
Further details
Captain James Cook is best known to American numismatists as the discoverer of the Sandwich Islands, later called the Hawaiian Islands. Cook was present at the capture of Quebec in 1759, and was the marine surveyor of Newfoundland and Labrador during 1764-68. The Royal Society's medal for James Cook is unusual, in that it has Cook's bust on the obverse in lieu of the standard bust of George III.