Phantom Islands of the Atlantic

Until the invention of modern navigational intruments (most notably the chronometer, in the 1730s, which enabled sailors to mark longitude), geographic calculations drew upon legends and unverifiable reports from ancient mariners who, sailing only by latitude and the stars, could not pinpoint precisely where they had been. Early cartographers filled their maps with the satanic beasts and horrific (or idyllic) landscapes the sailors described. As navigation became more scientific, these ""lands that never were"" disappeared from the maps. After presenting ancient and medieval geographical theories, Johnson, a sailor who has crossed the Atlantic five times in a 27-foot schooner, tells seven of these island tales. The Isle of Demons off Newfoundland was reputedly inhabited by bears, walruses and a variety of mythological animals. St. Brendan, a sixth-century Irish monk, was said to have discovered the islands that came to bear his name on a seven-year voyage that may have been a religious fantasy. The fifth century's Saint Ursula, legend has it, left Britain for Rome by boat, accompanied by 11,000 virgins. Johnson also tells of the tantalizing searches for Frisland, Buss Island, the Isle of Seven Cities and Hy-Brazil, a foggy green isle off the west coast of Ireland that was eyed as a midway station for trade to the Orient. This admirably researched and well-written account, with numerous maps and illustrations, vividly illustrates how interesting the often overlooked science of geography can be. BOMC and QPB selections. (Dec.)