About Atlantis, St Brendan's Island, Antillia, the Sunken Land of Buss, and other imaginary islands that medieval and early modern Europeans thought lie, or once lay, somewhere out in the Atlantic. Discusses the development of the legends, the mark they left on surviving maps, and the possible reality, if any, behind the islands. While very much a romantic wanting to believe legendary islands reflect ancient voyages and discoveries, Babcock is fairly levelheaded and refrains from insisting his pet conjectures are provable. He also deals with a few islands that undoubtedly do exist but whose cartographic history has been embellished by legend, notably Greenland and Corvo (the second westernmost of the Azores).

The book is from 1922; I read it in a 2015 reprint apparently made by scanning the original. The text has survived without suffering anything worse than an occasional slight haziness, but the illustrations of old maps are sadly pretty much ruined.