IN LATE 1815 IN LONDON, Thomas Smith, then about 16 years old, signed up as an apprentice on Norfolk, a 650-ton former warship that had passed into private hands. Smith had heard that the vessel was bound for Africa in search of gold and ivory, an impression reinforced by eager talk among the more experienced sailors of hunting down huge elephants. As the ship sailed south, the youngster learned that Norfolk’s actual destination was South Georgia, a bleak, windswept island in the South Atlantic Ocean some 1,200 miles east of the southern tip of South America. There, he would indeed be hunting elephants—sea elephants, or elephant seals, as they are now known.
Smith hung back warily during the first attack on a herd of elephant seals, enormous beasts that weigh…