A thoughtful and challenging consideration of the many voyagers who might have reached the Americas by sea before the Ni§a, the Pinta, and the Santa Maria. Starting with the proposition that the theory of the Bering Strait land-bridge, currently believed to be the route by which the first American arrived, is a ``Berlin Wall'' ready to fall, science-writer Huyghe (Omni, Science Digest, etc.) examines various sea alternatives as being more likely. By whatever means the New World was first reached, a rich legacy indicates that contact with the Old World was maintained. Ancient pottery found recently in Ecuador suggests definite Japanese influence, while fragments of a 4,000-year-old Chinese geographical survey describe landmarks and creatures located only on American shores. Tantalizing evidence of millennia of pre-Columbian contact is by no means limited to visitors from Asia, as tools and similar burial habits link northern maritime cultures on both sides of the Atlantic, and Phoenician and Carthaginian mariners left physical as well as linguistic signs of their presence on both American continents. The historical record includes more recent voyages also: a trip by the Irish monk St. Brendan in the sixth century; a period of extensive Norse exploration and colonization ranging from the seventh to the fourteenth centuries; and evidence in Mexico pointing to an African presence in that region. A final chapter raises the distinct possibility that Columbus was well aware of earlier journeys, and in fact used the information available to ensure his own successful maiden voyage. Well informed and well written, always provocative if not conclusive, this is revisionist history with a vengeance--and about time, too.