Benjamin Thompson

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Benjamin Thompson (painting by Thomas Gainsborough , 1783)

Sir Benjamin Thompson, Count Rumford ( Imperial Count of Rumford) (born March 26, 1753 in North Woburn , Massachusetts , † August 21, 1814 in Auteuil near Paris) was a British officer, politician, experimental physicist and inventor. He played an important role in the further development of thermodynamics .

Early years in America and England

Thompson's birthplace in Woburn, now a museum

Thompson was born to a small farmer in the town of Woburn , about 15 km northwest of Boston (now in the state of Massachusetts ). His father died when Thompson was a child. He attended the local village school and at the age of 13 began his apprenticeship with a merchant in nearby Salem . From an early age he showed great talent and a keen interest in mathematics and science. During a convalescent stay in Woburn in 1769, he carried out his first experiments to research heat.

Thompson then worked for a merchant in Boston and after a failed attempt to train as a doctor, as a teacher in Rumford (today: Concord , New Hampshire ). Together with Loammi Baldwin (1744–1807), who later became known as an engineer , he attended physical lectures by John Winthrop (1714–1779), professor of mathematics and natural philosophy at nearby Harvard University .

His social rise began when he married Sarah Walker Rolfe (* 1739, † January 19, 1792) in Rumford in 1772, a wealthy widow from a respected pastor's family thirteen years his senior. With her he moved to Portsmouth, New Hampshire , where he was part of the local upper class. The couple maintained close social ties with the colony's governor, John Wentworth, who made Thompson a major in the New Hampshire Militia in 1773 . Thompson's commitment to the English colonial power drew him the hostility of the majority of the population, which were increasingly revolutionary in the run-up to the North American War of Independence . After a crowd tried to storm his house, he left his wife and two-month-old daughter in November 1774 and fled to the British troops in Boston. There he worked for the British commander-in-chief, General Thomas Gage , whom he informed, among other things, of the strength of the armed rebels, which earned him the charge of espionage. When he returned to Woburn in the spring of 1775, he was tried but went unpunished. After this experience, he turned large parts of his fortune into cash and finally left his family in October 1775.

In 1776 he traveled on board a British warship from Boston to England and brought dispatches from General William Howe to the British Colonial Minister, Lord George Germain . Germain was so impressed with Thompson that he got him a job at the Colonial Department. Thompson carried out experiments on the explosive power of gunpowder and the speed of artillery projectiles, the results of which received wide attention when he published them in 1781 in the Philosophical Transactions of the Royal Society of London . Thompson showed that the popular belief that slightly moistened gunpowder had a higher effect was unfounded. He also developed a communications system for ships and improved firearms.

In 1779 Thompson became a member of the Royal Society and, in 1780, Secretary of State for the American Colonies. In 1781 he returned to America and set up a cavalry unit in New York, the "King's American Dragoons", as its commander he was appointed lieutenant colonel in spring 1782 and commanded Fort Huntington on Long Island .

Work in Munich

Rumford (right), with Friedrich Ludwig von Sckell and Elector Karl Theodor in the English Garden in Munich

At the beginning of 1783, before the peace agreement , Thompson returned to England, where he was promoted to colonel, but after the end of the War of Independence saw no more opportunities for the brilliant military career he had hoped for. Therefore, he took leave in 1784 and went to the continent to enter the service of Emperor Joseph II , as he expected a new war against the Turks ( Russian-Austrian Turkish War (1787-1792) ).

On the way to the imperial court in Vienna, he drew the attention of Maximilian , a nephew of the Bavarian elector Karl Theodor , in Strasbourg and in this way came to Munich , where the elector offered him to enter his service. After Thompson had ascertained in Vienna that the prospects for a military career there were not as good as hoped, he returned to London, where he officially said goodbye and from King George III. was knighted .

In Munich he was appointed adjutant and chamberlain and in 1788 commissioned to reorganize the Bavarian army , which was in a desolate state. Ordinary soldiers in particular were poorly paid, poorly fed, and poorly dressed. Thompson had the soldiers plant gardens in every garrison in order to improve their food supply, including in Munich in the area of ​​what is now the English Garden . He made use of his scientific interests for the reform of the army by doing research on the heat-insulating effect of uniform fabrics and inventing heat-storing underwear.

Thompson became a social reformer through the poverty and misery of the common soldiers. In order to remove the beggars from the streets, he had almshouses , schools for soldiers' children , workhouses and factories built and here too he used his scientific knowledge to improve the living conditions of the population: he invented the Rumford stove , an energy-saving kitchen stove that only consumed half as much fuel as the still widely used open stoves. His publication, On Chimney Fireplaces, on improving the fireplace , also attracted attention . He also designed an improved lime kiln, later known as the Rumford kiln.

Open fireplace to Rumford

For soup kitchens to feed the poor, he invented Rumford soup , a cheap but nutritious stew that was widely used in poor relief throughout Europe. Besides peas and pearl barley, potatoes were the main component of Rumford soup . So far, they have been suspiciously rejected by the Bavarian population, but Thompson propagated them as folk food. In 1789, work began on creating the English Garden - one of the first and to this day largest urban parks in the English style . It was opened to the public in May 1792.

Due to his success, Thompson rose to the ranks of major general, lieutenant general and commander in chief of the army in 1788 to Secretary of War and Chief of Police. In 1785 he was made an honorary member of the Kurbayerische Akademie der Wissenschaften , and in 1789 he was elected to the American Academy of Arts and Sciences . When the Bavarian elector was imperial vicar of the Holy Roman Empire during the interregnum between Joseph II and Leopold II in 1790 , he raised Thompson to the rank of imperial count with the title "Graf von Rumford" . In 1795/96 Rumford stayed in London, where he also invited his daughter from America, donated $ 5,000 each to the Rumford Medal of the Royal Society, which he himself became the first recipient in 1800, and the Rumford Prize of the American Academy of Arts and Sciences. After his return to Munich, Rumford succeeded in 1796 - the elector had fled - as chairman of the Council of State, through diplomatic skill in negotiations with the Austrians and the French, to save the city of Munich from destruction during the war.

Scientific achievements

Statue of Thompson in front of the library in his hometown of Woburn, Massachusetts (copy of the Munich statue)
Statue of Thompson in Munich

In 1792 Thompson received the Copley Medal from the Royal Society. During his time in Munich he continued his scientific experiments. So he resumed the experiments to measure the explosive force of gunpowder and published the results on May 4, 1797 in a paper for the Royal Society. In particular, he pursued his research on the nature of heat. He developed a method for measuring the specific heat of fabrics, for which Johannes Wicke claimed priority, and examined the heat-insulating properties of materials such as fur, wool and feathers. He rightly attributed their insulating ability to the fact that they lock in the air and thereby prevent convection . Thompson also came to the daring and false assumption that gases cannot conduct heat, which he later extended to liquids. Although this thesis could not be refuted metrologically at the time, it encountered lively opposition, especially from John Dalton and John Leslie .

Thompson's significance in the history of science for the development of heat theory is mainly based on his famous attempts at cannon drilling in 1798. In the royal gun foundry , the soul of the cast bronze guns was drilled out with steel drills. The associated considerable heat generation aroused Thompson's scientific curiosity and aroused his doubts about the then generally accepted material theory of heat . This theory, formulated by Lavoisier in 1787, postulated the existence of a "warmth element" called " caloricum ", an invisible, weightless liquid-like substance bound in the body.

Thompson measured the heat generated during drilling and found that the amount of heat released over a longer period of time would have been sufficient to melt the cannon barrel in a short time. From this he concluded that such a large amount of heat could not be trapped in the original gun barrel. In addition, the heat generated during drilling remained the same for any length of time and with repeated drilling operations on the same pipe. If the drilling was done long enough, any amount of heat could be generated. The conclusion derived from this that mechanical friction is an inexhaustible source of heat, refuted the thermal substance theory, according to which the heat bound in the gun barrel and released during drilling should have run out at some point. Thompson concluded from his experimental results that heat cannot be a substance, but must be a form of movement, thus creating the basis for the modern theory of heat as energy and the first law of thermodynamics .

Thompson developed various devices for heating food and by chance discovered low-temperature cooking with his kitchen assistants , because a shoulder of mutton, which remained overnight in an extinguished potato drying box, had reached a perfect degree of doneness.

Last years of life

Benjamin Thompson

In 1799 Rumford was to go to the British court as Bavarian envoy. As a British subject he could not be accredited in this function, but remained in London as a private agent for the Bavarian government. Due to his initiative, the Royal Institution of Great Britain was founded in early March 1799 as a research and training facility for applied natural sciences. In April 1799 a house was purchased on Albemarle Street, Mayfair , in central London. Rumford became the institution's secretary, Thomas Garnett (1766-1802) was its first lecturer, and George Finch was its first president. Thompson proposed Humphry Davy as its first director, but there was considerable friction as a result.

Rumford turned down the offer of US President John Adams to set up and direct a military academy in the United States (later the West Point Academy ), combined with his appointment as Inspector General of Artillery. In 1801 he was elected a member of the Royal Society of Edinburgh and in 1802 a foreign member of the Göttingen Academy of Sciences . In the same year he went to Paris, where he finally settled in 1804, became a member of the Institut de France ( Académie des sciences ) and in 1805 married Marie Lavoisier , the wealthy widow of the chemist Antoine Laurent de Lavoisier , who was guillotined in 1794 and herself a chemist. The marriage was not very happy; the couple separated as early as 1807, and in 1810 the marriage was divorced. Rumford settled in Auteuil near Paris, where he continued his research and inventions (including a coffee machine) and died in 1814 after a sudden attack of fever. He bequeathed $ 50,000 to Harvard University , which in 1816 established the Rumford Chair of Applied Physics and Mathematics.

Rumford's daughter Sarah (born October 18, 1774, † December 2, 1852), from her first marriage to Sarah Walker Rolfe, was probably the first American woman to inherit the title of countess. Thompson was buried in the Auteuil Cemetery in Paris, Cimetière d'Auteuil in 1814 .

Thompson's grave on the Cimetière d'Auteuil (Paris)

Thompson was undoubtedly a colorful, contradicting personality: on the one hand a womanizer and careerist who was concerned about his own advancement, regardless of others, on the other hand, through his work in Munich, a benefactor of humanity, plus a man of genuine scientific interest who, despite limited theoretical knowledge, has given important impulses for the further development and utilization of physics through his practical ingenuity.

Honors

A street in Munich's Gärtnerplatzviertel and the Rumfordhaus in the English Garden are named after Rumford , today a municipal youth recreational facility . Also in the English Garden, at the south end, there is a memorial stone that commemorates the philanthropist as the creator of the garden. His statue, created by Kaspar von Zumbusch , is on Maximilianstrasse . His bust was placed in the Hall of Fame .

Fonts (selection)

  • Research sur la chaleur . Paris 1804-1813.
  • Research on les bois et le charbon . Paris 1813.
  • Essays political, economical and philosophical . 4 volumes, London 1796-1803; (German: Weimar 1800–1805)
  • Complete Works . Edited by George E. Ellis, 5 volumes. London / Boston 1876.
  • Thompson, Benjamin: Experiments on the Production of Dependent Air from Water with Various Substances. In a Letter from Sir Benjamin Thompson, Knt. FRS to Sir Joseph Banks, Bart. PRS Phil. Trans. R. Soc. Lond. January 1, 1787 77: 84-124; doi : 10.1098 / rstl.1787.0015 (PDF; 6.4 MB)
  • Thompson, Benjamin; Blagden, Charles : Experiments Made to Determine the Positive and Relative Quantities of Moisture Absorbed from the Atmosphere by Various Substances, under Similar Circumstances. By Sir Benjamin Thompson, Knt. FRS; Communicated by Charles Blagden, MD Sec. RS Phil. Trans. R. Soc. Lond. January 1, 1787 77: 240-245; doi : 10.1098 / rstl.1787.0022 (PDF; 717 kB)

literature

  • Åkerman, Juliane from: Benjamin Thompson, Earl of Rumford . In: Wurst, Jürgen and Langheiter, Alexander (Ed.): Monachia. Munich: Städtische Galerie im Lenbachhaus, 2005. S. 159. ISBN 3-88645-156-9
  • Karl Maximilian von Bauernfeind :  Rumford, Benjamin Thompson Graf von . In: Allgemeine Deutsche Biographie (ADB). Volume 29, Duncker & Humblot, Leipzig 1889, pp. 643-655.
  • Duane Bradley. Count Rumford: Strange American . Van Nostrand, Princeton 1967.
  • George I. Brown: Earl Rumford. The Adventurous Life of Benjamin Thompson . dtv, Munich 2002, ISBN 3-423-24342-2 (English original edition: George I. Brown: Count Rumford: The Extraordinary Life of a Scientific Genius - Scientist, Soldier, Statesman, Spy.Sutton Publishing, Gloucester 2001, ISBN 0- 262-02138-2 ).
  • SC Brown: Benjamin Thompson, Count Rumford . MIT Press, Cambridge USA 1981, ISBN 0-262-02138-2 .
  • DSL Cardwell: From Watt to Clausius: The Rise of Thermodynamics in the Early Industrial Age . Heinemann, London 1971, ISBN 0-435-54150-1 , pp. 95-107.
  • Ludwig Hammermayer:  Rumford, Benjamin Thompson Count of. In: New German Biography (NDB). Volume 22, Duncker & Humblot, Berlin 2005, ISBN 3-428-11203-2 , pp. 244-246 ( digitized version ).
  • E. Larsen: An American in Europe: The life of Benjamin Thompson, Count Rumford . Rider, London and New York 1953.
  • Hans-Erhard Lessing: Mannheim pioneers . Wellhöfer-Verlag, Mannheim 2007.
  • V. Orton: The Forgotten Art of Building a Good Fireplace: The Story of Sir Benjamin Thompson, Count Rumford, an American Genius & His Principles of Fireplace Design Which Have Remained Unchanged for 174 Years . Alan C. Hood and Company Inc, York 2000, ISBN 0-911469-17-6 .
  • WJ Sparrow: Knight of the White Eagle: A biography of Sir Benjamin Thompson, Count Rumford, 1753-1814 . Hutchinson, New York 1964.

Movie

“ Sir Benjamin Thompson, An American Becomes Bavarian Minister ”, a BR documentary by Bernhard Graf , 2014.

Web links

Commons : Benjamin Thompson  - Album with pictures, videos and audio files
Wikisource: Benjamin Thompson  - Sources and full texts

Individual evidence

  1. ↑ Hund, Friedrich: History of physical terms. Vol. 1, Mannheim (1978), pp. 209-210
  2. ↑ Benjamin Thompson: The complete works of Count Rumford (1870), Essays, political, economical, and philosophical, Volume 3 , p. 188. PDF (English) , search term drying potatoes . Retrieved November 19, 2012.
  3. ^ Fellows Directory. Biographical Index: Former RSE Fellows 1783–2002. (PDF file) Royal Society of Edinburgh, accessed April 15, 2020 .
  4. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 207.
  5. ↑ Christa Jungnickel, Russell McCormmach: Cavendish. The Experimental Life. Bucknell, Pennsylvania 1999, p. 479-484
personal data
SURNAME Thompson, Benjamin
ALTERNATIVE NAMES Earl Rumford
BRIEF DESCRIPTION British officer, politician, experimental physicist and inventor
DATE OF BIRTH March 26, 1753
PLACE OF BIRTH North Woburn , Massachusetts
DATE OF DEATH August 21, 1814
Place of death Auteuil near Paris