Ganong's contributions to cartography are enormous: for example, his reconstruction of Cabot's voyages, while all may not agree with it, is a masterpiece of inductive analysis which will remain a model in historical research; his chapters on Gomez, Verrazzano and Fagundes are still the chief secondary sources on these discoverers. There have been notable additions to the bibliography of discovery and maps since Ganong wrote; recently published works as well as the complete file of Ganong's correspondence with his fellow cartographer, G.R.F. Prowse, were consulted by Theodore E. Layng, Map Division, Public Archives of Canada, in preparing the commentaries which accompany this edition of Crucial Maps. These commentaries, with Mr. Layng's introduction, also provide an interesting sketch of Dr. Ganong and his work. Another important feature of this edition is the index prepared by William Morley of the John Carter Brown Library. In much of his work Ganong was a pioneer, and, while subsequent studies have reached different conclusions on some points, many of his results have seldom been challenged. Students of the present and future will still use and quote from . Royal Society of Canada Special Publications No. 7