I am by no means the first to be convinced that no sharp line can be drawn separating fiction from history. The Mapmaker is a novel, ant yet real history is an integral part of every page. Andrea Blanco, the mapmaker of this story, actually lived, as did Fra Mauro, Bartholomeu di Perestrello, Prince Henry of Portugal, a Norse ship-master called Ballarte, a Venetian alley captain named Alvise de Cadamosto, the geographer Jahuda Cresques, and many others who appear in the succeeding pages.

Some fifty years before the epic voyage of Christopher Columbus, Andrea Bianco drew one of the first maps of the world. Upon it appear several islands with a amazing resemblance to Cuba, Jamaica, one the Bahamas, and at least the southern part of Florida. The Bianco, map in turn, seems to have been patterned after the ''Nautical Chart of 1424,'' the original of which is now in the James Ford Bell Collection at the University of Minnesota.--Partial EXCERPT from Author's Preface, dated Nov. 2, 1956