In late nineteenth-century America, Simon Newcomb was the nation's most celebrated scientist and--irascibly, doggedly, tirelessly--he made the most of it. Officially a mathematical astronomer heading a government agency, Newcomb spent as much of his life out of the observatory as in it, acting as a spokesman for the nascent but restive scientific community of his time.

Newcomb saw the "scientific method" as a potential guide for all disciplines and a basis for all practical action, and argued passionately that it was of as much use in the halls of Congress as in the laboratory. In so...