Portrait of Benjamin Thompson, Count Rumford.

Portrait of Benjamin Thompson, Count Rumford.

H418/0060 Rights Managed

Request low-res file

530 pixels on longest edge, unwatermarked

Request/Download high-res file

Uncompressed file size: 27.4MB

Downloadable file size: 1.8MB

Price image Pricing

Please login to use the price calculator



Caption: Portrait of American-British physicist Count Rumford (1753-1814), born Benjamin Thompson. Rumford was one of the first to question the caloric theory which regarded heat as a fluid (caloric) which could be poured from one substance to another. Whilst boring cannons, he studied the way the metal blocks grew hot as they were bored out. He concluded that the mechanical motion of the borer was being converted to heat & was the first to set a figure for the mechanical equiva- lent of heat. He also weighed a quantity of water as water & as ice & detected no change in weight, showing that if caloric existed it must be weight- less. This further weakened the caloric theory.

Release details: Model release not available. Property release not required.

Keywords: benjamin (rumford), count, heat, physicist, pioneer, portraits, rumford, surname r, thermodynamics, thompson

Licence fees: A licence fee will be charged for any media (low or high resolution) used in your project.