When Samuel Hearne, on foot, reached the central Arctic shore of North America in 1771, he finished a centuries-old will-o'-the-wisp of the European imagination--a navigable Northwest Passage through or north of the Americas from Europe to Asia--until it was recently revived by giant tankers and icebreakers. Explorers such as James Cook and John Franklin continued to be instructed to search for it, but the testimony is more to the stubbornness of myths than to the inconclusiveness of Hearne's evidence. For the rest of his life Hearne worked on A Journey from Prince of Wales's Fort, in Hudson's Bay, to the Northern Ocean, which was published posthumously in 1795. It is among the most engaging of travel books: lucid and, as appropriate, informative, dramatic, ironic, or amusing. For travelers in British North America, his work is the prototype in style and structure of explorers' and traders' journals transformed into narratives.

Hearne...