Count Rumford(1753–1814)

Benjamin Thompson was born at Woburn in the Massachusetts Bay Colony on the twenty-sixth of March 1753, son of a small Massachusetts farmer who died when the boy was two. He was raised by his uncle on a New England farm, was apprenticed at thirteen to a Salem merchant, served as a junior teacher at the Concord (then Rumford) academy from sixteen, and at nineteen married Sarah Walker Rolfe, a wealthy Concord widow fourteen years his senior. The Rolfe-Rumford marriage gave him the small fortune that founded the next decade of his New England career, the patronage of the Royal Governor John Wentworth of New Hampshire (who commissioned him a Major in the 2nd New Hampshire Militia in 1772), and the ground from which he pursued the experimental-philosophical interests in chemistry, ballistics and gunpowder that became his lifelong work.

He took the Loyalist side at the outbreak of the American Revolution in 1775, served as a confidential courier to the British forces in Boston through 1775 and 1776, was driven out of New England on the British evacuation of Boston in March 1776, and sailed to London with a sequence of confidential reports on the American Revolutionary Army's position. He was retained at the Colonial Office as a confidential aide on American affairs from 1776, was appointed Under-Secretary of State for the American Department in 1780 in his twenty-seventh year, served briefly in command of a Loyalist cavalry regiment in the closing campaigns of the war 1781 to 1783, and on the conclusion of the war took service in the Holy Roman Empire under the Elector Karl Theodor of Bavaria in 1784 in his thirty-first year.

He served the Elector at Munich for the next eleven years (1784 to 1795) as Minister of War, Minister of the Interior and Grand Chamberlain. He reformed the Bavarian Army from the Habsburg-court parade institution he had inherited into a working operational force, reorganised the Munich military commissariat on systematic supply principles, designed the standard uniform and the camp-kitchen equipment, and set up the institutional Bavarian Army on the model that ran for the next forty years. He reformed the Munich poor-relief system through the founding of the Munich Workhouse of 1790 (he combined the Munich beggars' guild into a single workhouse that employed three thousand of the city's homeless population in the manufacture of military uniforms and equipment, the workhouse providing housing, food and basic schooling on the strength of the manufacturing income, the foundational model of the European workhouse system of the next century). He was created Count Rumford of the Holy Roman Empire by the Elector in 1791 (the patent took the title from his New Hampshire town of Rumford, the modern Concord).

His central scientific work came at Munich. He had been commissioned in the late 1790s as Inspector of the Munich Arsenal cannon-boring works. He observed in the boring of brass cannon (a process that fitted a steel drill-bit against a casting and turned the casting by horse-power) that the cannon-blanks produced unlimited quantities of heat under the boring operation, far in excess of any heat that the existing caloric theory of heat (the standard heat-fluid theory of late-eighteenth-century chemistry) could account for. He set up in 1797 a controlled experimental apparatus at the arsenal in which a horse-powered borer turned a brass casting submerged in water-tank; the water came to boiling in two hours and continued to boil indefinitely while the horse continued to work. He published the result in his 1798 paper to the Royal Society of London An Experimental Inquiry Concerning the Source of the Heat which is Excited by Friction, in which he set out the foundational observation that heat was not a finite material fluid but was generated indefinitely by mechanical work, the central single experimental result on which the nineteenth-century kinetic theory of heat and James Prescott Joule's 1845 mechanical-equivalent-of-heat measurement rested.

He returned to England in 1799 in his forty-sixth year, founded with Sir Joseph Banks and the Royal Society in March 1799 the Royal Institution of Great Britain (at the leased premises at 21 Albemarle Street in Mayfair, where the Institution remains today), as the institutional vehicle for the public lecture-demonstration of the new experimental philosophy to the educated London audience. He served as Director of the Institution from 1799 to 1801, recruited Humphry Davy as the Institution's first Professor of Chemistry in 1801 (Davy's electrochemical-elementary-isolation work in the Albemarle Street basement laboratory of the next decade produced the isolation of sodium, potassium, calcium, magnesium, strontium and barium and the central electrochemistry of the early nineteenth century), and laid out the public-lecture programme that has been the Institution's central public face for the next two centuries. He moved to Paris in 1804, married the widow of the chemist Lavoisier in 1805 (the marriage failed within four years and ended in formal separation in 1809), and died at Auteuil outside Paris on the twenty-first of August 1814 in his sixty-second year. The Royal Institution today operates the Faraday Museum, the Christmas Lectures (continuously broadcast on BBC television since 1936), and the public-lecture programme on the model Rumford founded in 1799. The Thompson name in modern science carries the weight of the Munich cannon-boring experiment of 1797 and the Royal Institution of 1799.