The mechanical theory of heat and Rumford's contribution

Benjamin Thompson, Bavarian Minister of War, went into the workshop to supervise the production of new cannons. As you may notice, Benjamin Thompson is not really a common Bavarian name, and act ually, Thompson was not a Bavarian citizen but he was born in the British colonies in North America. At the time he was entering the workshop there were no more British colonies in North America – the events were are going to discuss took place by the end of the 18th century. During the American Revolution, Thompson had acted as a spy for the British, consequently he had to leave when things turned out to end bad for them. Why a North American could become the Bavarian Minister of War is a completely different story and should not bother us here. But evidently, the supervision of the production of weaponry was amongst the duties of a Minister of War, at least in those days. Europe was at the Edge of War, the French Revolution and the following Empowerment of Napoleon put a threat to all European rulers, and thus there would be war – well, in fact there was already military conflict. Consequently, new cannons were needed, and consequently, Benjamin Thompson had to go to the workshop to make sure that the work was going efficient and that the quality of the weapons was as expected. ...

Canons against Calorics

05/05/2021 148 KB (PDF)

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Biographies und historical backgrounds

Filename Date Size / type
Historical background: Energy 05/05/2021 1 MB (PDF)
hintergrund-energie-de.pdf 05/05/2021 1 MB (PDF)
Biography: Sir Benjamin Thompson 05/05/2021 615 KB (PDF)

Educational Resources

Filename Date Size / type
Suggestions to Teachers 05/05/2021 191 KB (PDF)
Student’s Learning Activities 05/05/2021 331 KB (PDF)

Storytelling Resources

Historical Resources

A Primary Sources

Rumford, Benjamin Count of: An Inquiry Concerning the Source of the Heat Which is Excited by Friction. By Benjamin Count of Rumford, in: Philosophical Transactions of the Royal Society of London 88 (01.01.1798), S. 80–102, available online:
Rumford, Benjamin Count of: An Inquiry Concerning the Weight Ascribed to Heat, in: Philosophical Transactions of the Royal Society of London 89 (01.01.1799), S. 179–194, available online:

B Secondary Sources

Brown, Sanborn Conner: Benjamin Thompson - Count Rumford: Count Rumford on the Nature of Heat, Oxford u.a. 1967.
Goldfarb, Stephen J.: Rumford’s Theory of Heat: A Reassessmensiehe auch:t, in: The British Journal for the History of Science 10, Ausgabe 01 (1977), S. 25, available online:
Brown, George I.: Graf Rumford. Das abenteuerliche Leben des Benjamin Thompson, München, 2002 (Populärwissenschaftliche Biographie).
Heering, Peter: An Experimenter’s Gotta Do What an Experimenter’s Gotta Do—But How?, in: Isis 101, Ausgabe4 (01.12.2010), S. 794–805, available online: 
(Aufsatz zu historischen Experimentalpraxen und dem Verhältnis des Experimentators zu seinen Instrumenten).

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Story and all resources 2 MB (ZIP)