Benjamin Thompson
Born 1753 · Age 272
American-born British military officer, scientist and inventor (Count Rumford). Loyalist in the American Revolution; reorganized the Bavarian army; conducted foundational experiments on heat; inventor of the Rumford fireplace and other practical devices; co-founder of the Royal Institution; endowed Rumford awards and chair.
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Life & Career Timeline
Born in Woburn, Massachusetts
Benjamin Thompson born in rural Woburn, Province of Massachusetts Bay (birthplace now preserved as a museum).
Apprenticed to merchant John Appleton
At about age 13 Thompson was apprenticed to John Appleton in nearby Salem, exposing him to refined society and sparking interest in science.
First experiments on heat while recuperating
While recuperating from an injury in Woburn, Thompson conducted his first experiments studying the nature of heat and began corresponding with peers about them.
Married Sarah Rolfe (née Walker)
Met, charmed, and married Sarah Rolfe, a wealthy widow with property at Rumford (old name for Concord, NH); marriage elevated his social standing and influence.
Appointed major in New Hampshire militia
Through his wife's influence with the governor Thompson was appointed a major in the New Hampshire Militia.
Birth of daughter Sarah
Thompson and Sarah Rolfe had a child (also named Sarah) in 1774.
Became Loyalist and fled to British lines after mob attack
During the American Revolution Thompson supported the Loyalists, was stripped of command, his house was attacked and burned by Patriots, and he fled to British lines.
Financed King's American Dragoons
Thompson financed his own military unit, the King's American Dragoons, which served primarily on Long Island in 1782–1783.
Published experiments on gunpowder
Published 'New Experiments upon Gun-Powder' in the Philosophical Transactions of the Royal Society (1781); results were widely acclaimed and boosted his scientific reputation in London.
King's American Dragoons activity at Fort Golgotha
Thompson's unit earned notoriety for demolishing a church and burial ground in Huntington to erect Fort Golgotha (action in 1782).
Moved to London after the war
At the end of the American Revolutionary War Thompson arrived in London with a growing reputation as an accomplished scientist and administrator.
Knighted by King George III
Recognized for administrative talents in London, Thompson received a knighthood from George III.
Moved to Bavaria; entered Prince-elector's service
Thompson relocated to the Electorate of Bavaria and became aide-de-camp to Prince-elector Charles Theodore, reorganizing the Bavarian army and public institutions.
Published 'New Experiments upon Heat' and expanded heat research
Continued experimental work on heat, publishing significant papers (including 1786) on the nature and propagation of heat.
Established workhouses and social reforms in Bavaria
Set up workhouses for the poor, improved soldier diet and clothing, and encouraged practical reforms (e.g., Rumford's Soup, potato cultivation).
Received Order of the White Eagle (Poland–Lithuania)
Honoured with the Order of the White Eagle.
Created the Englischer Garten in Munich
On behalf of Prince Charles he laid out the Englischer Garten in Munich (1789), one of the largest urban public parks still existing today.
Elected Foreign Honorary Member of the American Academy of Arts and Sciences
Recognized by the American Academy for his scientific contributions.
Made Imperial Count (Reichsgraf von Rumford)
Received the title Reichsgraf von Rumford in recognition of his services to Bavaria; adopted the name 'Rumford' from Rumford, NH (old name for Concord).
Awarded the Copley Medal
Received the prestigious Copley Medal for scientific contributions (listed as Copley Medal 1792).
Work in photometry; introduced the 'standard candle'
Conducted photometry work and introduced a 'standard candle' based on sperm-oil as a unit of luminous intensity (predecessor to the candela).
Published Essay on Chimney Fire-Places
Published 'An Essay on Chimney Fire-Places' (1796), proposing improvements to fireplaces to save fuel and prevent smoking; led to the widely imitated 'Rumford fireplace'.
Introduced the Rumford fireplace in London
Modified fireplace designs (angled side walls, chimney choke) to improve updraught and efficiency; the design became fashionable and reduced smoke in London homes.
Published on propagation of heat in fluids
Published 'On the propagation of heat in fluids' (1797), advancing his studies on insulating properties and heat transmission.
Published 'An Inquiry Concerning the Source of the Heat Which Is Excited by Friction'
Argued friction-generated heat was a form of motion (early challenge to the caloric theory) based on experiments boring cannon barrels in Munich; a key contribution to the development of energy conservation concepts.
Co-founded the Royal Institution of Great Britain
With Sir Joseph Banks, Thompson established the Royal Institution in 1799 and helped set its direction; Sir Humphry Davy became the first lecturer.
Established the Rumford Medal (endowment)
Endowed the Rumford medals (awarded by the Royal Society and American Academy) to recognize discoveries in heat and light; medal first awarded c.1800.
Elected foreign member of the Royal Swedish Academy of Sciences
Recognized by the Swedish Academy for scientific achievements; also a member of the American Philosophical Society.
Married Marie-Anne Lavoisier
Married Marie-Anne Lavoisier, widow of chemist Antoine Lavoisier; the marriage lasted about three years before separation.
Separated from second wife
After approximately three years of marriage to Marie-Anne Lavoisier, Thompson separated and settled in Paris to continue scientific work.
Developed practical kitchen inventions (double boiler, range, percolator)
Between ~1810 and 1814 Thompson developed and/or described inventions including the double boiler, a kitchen range, and a coffee percolator (percolating coffee pot).
Improved quicklime kilns (Rumford furnaces)
Significantly improved kiln design to produce quicklime uncontaminated by fuel ash; Rumford furnaces were built across Europe.
Bequeathed endowments (Rumford Chair, medals)
On death he endowed the Rumford Chair of Physics at Harvard and left funds for the Rumford medals (bequests/establishments associated with his estate).
Died in Paris
Benjamin Thompson (Count Rumford) died in Paris on 21 August 1814; buried in the cemetery of Auteuil.
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