In the two centuries before Columbus, mapmaking was transformed. The World Map, 1300-1492 investigates this important, transitional period of mapmaking. Beginning with a 1436 atlas of ten maps produced by Venetian Andrea Bianco, Evelyn Edson uses maps of the fourteenth and fifteenth centuries to examine how the discoveries of missionaries and merchants affected the content and configuration of world maps.

She finds that both the makers and users of maps struggled with changes brought about by technological innovation--the compass, quadrant, and astrolabe--rediscovery of...