Benjamin Thompson, the son of a New England farmer, had little formal schooling. After being injured in a fireworks accident while serving as a merchant's apprentice, he became a teacher in Rumford (now Concord), New Hampshire. There at age 19 he married a wealthy widow, Sarah Walker Rolfe. During the American Revolution, Thompson was an active Tory who served the British king by spying on his countrymen. After the fall of Boston in 1775, he fled to England, leaving behind his wife and daughter. During the war, Thompson served as undersecretary of state for the colonies and briefly as a British lieutenant colonel. In 1783 he joined the court of the elector of Bavaria where he instituted numerous social reforms including workhouses for Munich beggars. Thompson also introduced Watt's steam engine and the potato to the continent. For his numerous services to Bavaria the elector made Thompson a count in the...