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 doing, he not only sparked popular support for American science but also confronted a wide spectrum of social, cultural, and intellectual issues. This first full-length study of Newcomb traces the development of his faith in science and ranges over topics of great public debate in the Gilded Age, from the reform of economic theory to the recasting of the debate between science and religion. Moyer's portrait of a restless, eager mind also illuminates the bustle of late nineteenth-century America.