In the first book-length history of the Board of Longitude, a distinguished team of historians of science bring to life one of Georgian Britain's most important scientific institutions. Having developed in the eighteenth century following legislation offering rewards for methods to determine longitude at sea, the Board came to support the work of navigators, instrument makers, clockmakers and surveyors, and assembled the Nautical Almanac. Utilizing the archives and records of the Board, recently digitised by the same team, the authors shed new light on the Board's involvement in colonial projects, Pacific and Arctic exploration, as well as on innovative practitioners whose work would otherwise be lost to history. This is an invaluable guide to science, state and society in Georgian Britain, a period of dramatic industrial and imperial and technological expansion.