Mackenzie, who discovered the first northwest passage, from Montreal to the Pacific, cuts a rugged figure in this account of his youthful exploits. A Scot, he came to Canada to make his fortune, but his consuming dream was the discovery of the fabled Northwest Passage. A small, slight man, he forced himself to acquire an incredible strength and endurance. In 1789, on his first attempt to reach the Pacific, he discovered the Mackenzie River, the Mackenzie Mountains and a passage to the Arctic Ocean. Four years later, with the benefit of advanced learning at Cambridge, he tried again. The difficulties of portage, occasional scarcity of food, the danger and deviousness of savages, rains and rapids, all produce endless problems Mackenzie solved with ingenuity. He returned world famous to Montreal and became one of the richest men in Canada, retired from adventure at thirty, hobnobbed with royalty in London, and married happily Mr. Vail's admiration for his subject is well-founded in this sturdy, steadily interesting, biography.