Editing Benjamin Thompson (section)

==Science and engineering==
{{Blockquote|text=Benjamin Thompson ... has many claims on the interest of the historian of science. ... He founded the Royal Institution ... His methods of conservation of heat and economy of fuel, his designs of stoves, fireplaces and cooking utensils were widely used during his lifetime. He was consulted on the laying out of kitchens in hospitals and institutions ... He taught his contemporaries to recognise the fire built on an open hearth, the only means of domestic heating and cooking with which they were acquainted, for the ineffective and wasteful contrivance it really was. He held the most enlightened views, ... far in advance of his time, on the waste of fuel and the evils of atmospheric pollution in cities. ... 
Rumford's constant preoccupation ... was the application of scientific principles to the improvement of the lot of the poor and the working classes, and it was in the subject of heat and its utilization that he found the greatest outlet for his endeavours.{{Sfn|Martin|1951|p=144}}|author=Thomas Martin|title=The Experimental Researches of Benjamin Thompson, Count Rumford}}

===Experiments on heat===
{{See also|Heat transfer#History}}
His experiments on gunnery and explosives led to an interest in heat. He devised a method for measuring the [[specific heat]] of a solid substance but was disappointed when [[Johan Wilcke]] published his parallel discovery first.

Thompson next investigated the [[Thermal insulation|insulating properties of various materials]], including [[fur]], [[wool]] and [[feather]]s. He correctly deduced that the insulating properties of these natural materials arise from the fact that they inhibit the [[convection]] of air. He then inferred — incorrectly — that air and, in fact, all gases, were perfect non-[[heat conduction|conductors]] of heat.<ref>Rumford (1786)   "New experiments upon heat"  ''[[Philosophical Transactions|Philosophical Transactions of the Royal Society]]'' ''p.''273</ref><ref>Rumford (1792) [https://www.jstor.org/stable/106776 "Experiments upon heat"] ''Philosophical Transactions of the Royal Society'' ''p.''48-80</ref> He further saw this as evidence of the [[argument from design]], contending that [[divine providence]] had arranged for fur on animals in such a way as to guarantee their comfort. <!--This needs a reference, and should probably appear in trivia--> <!--Based on this work he created the [[Baked Alaska]] in 1804{{Citation needed|date=November 2010}}.-->

In 1797, he extended his claim about non-conductivity to liquids.<ref>Rumford (1797) "On the propagation of heat in fluids" ''[[Nicholson's Journal]]'' '''1''' ''pp''298–341</ref> The idea raised considerable objections from the scientific establishment, [[John Dalton]]<ref>Cardwell (1971) ''p.''99</ref> and [[John Leslie (physicist)|John Leslie]]<ref>{{cite book | author=Leslie, J. | title=An Experimental Enquiry into the Nature and Propagation of Heat | publisher=London | year=1804 }}</ref> making particularly forthright attacks. Instrumentation far exceeding anything available in terms of accuracy and precision would have been needed to verify Thompson's claim. Again, he seems to have been influenced by his theological beliefs,<ref>Rumford (1804) "An enquiry concerning the nature of heat and the mode of its communication" ''Philosophical Transactions of the Royal Society'' ''p.''77</ref> and historian of science [[D. S. L. Cardwell]] speculated that Thompson wished to grant water a privileged and providential status in the regulation of human life.<ref>Cardwell (1971) ''p.''102</ref>

He is considered the founder of the [[sous-vide]] food preparation method owing to his experiment with a mutton shoulder. He described this method in one of his essays.<ref>Benjamin Count of Rumford, "Essay X: On the construction of kitchen fire-places and kitchen utensils together with remarks and observations relating to the various processes of cookery; and proposals for improving that most useful art", ''Essays, Political, Economical, and Philosophical'', vol. 3 (London, England:  T. Cadell jun. and W. Davies, 1802), [https://books.google.com/books?id=gZg-AQAAIAAJ&pg=PA18 pp. 18–20.]</ref>

===Mechanical equivalent of heat===
{{Main|An Inquiry Concerning the Source of the Heat Which Is Excited by Friction}}
{{see also |Mechanical equivalent of heat}}
Rumford's most important scientific work took place in Munich, and centred on the nature of heat, which he contended in "[[An Inquiry Concerning the Source of the Heat Which Is Excited by Friction]]" (1798) was not the [[Caloric theory|caloric]] of then-current scientific thinking but a form of ''[[motion (physics)|motion]]''. Rumford had observed the frictional heat generated by boring cannon at the arsenal in Munich. Rumford immersed a cannon barrel in water and arranged for a specially blunted boring tool.<ref>{{cite book | last = Rosen | first = William | title = The most powerful idea in the world : a story of steam, industry, and invention | publisher = Random House | location = New York | year = 2010 | isbn = 978-1400067053 |page=274}}</ref> He showed that the water could be boiled within roughly two and a half hours and that the supply of frictional heat was seemingly inexhaustible. Rumford confirmed that no physical change had taken place in the material of the cannon by comparing the specific heats of the material machined away and that remaining.

Rumford argued that the seemingly indefinite generation of heat was incompatible with the caloric theory. He contended that the only thing communicated to the barrel was motion.

Rumford made no attempt to further quantify the heat generated or to measure the mechanical equivalent of heat. Though this work met with a hostile reception, it was subsequently important in establishing the laws of [[conservation of energy]] later in the 19th century.

===Calorific and frigorific radiation===
He explained [[Marc-Auguste Pictet|Pictet's experiment]], which demonstrates the reflection of cold, by supposing that all bodies emit invisible rays, undulations in the ethereal fluid.<ref>{{cite web
 | title = Pictet's experiment: The apparent radiation and reflection of cold
 | author = James Evans and Brian Popp
 | publisher = Am. J. Phys. 53 (8)
 | year = 1985
 | pages = 737–753
 | url = http://www2.ups.edu/faculty/jcevans/Pictet's%20experiment.pdf
 }}</ref> He did experiments to support his theories of calorific and frigorific radiation and said the communication of heat was the net effect of calorific (hot) rays and frigorific (cold) rays and the rays emitted by the object. When an object absorbs radiation from a warmer object (calorific rays) its temperature rises, and when it absorbs radiation from a colder object (frigorific rays) its temperature falls. See note 8, "An enquiry concerning the nature of heat and the mode of its communication" Philosophical Transactions of the Royal Society, starting at page 112.{{Full citation needed|date=May 2020}}

===Inventions and design improvements===
[[Image:Rumford fire2.jpg|thumb|left|Section of Rumford fireplace]]
<!-- Deleted image removed: [[Image:Rumford 5.jpg|thumb|Rumford's coffee percolator]] -->

Thompson was an active and prolific inventor, developing improvements for chimneys, fireplaces and industrial furnaces, as well as inventing the double boiler, a [[kitchen range]], and a [[Coffee percolator|coffee percolator roughly between 1810 and 1814]]. He invented a percolating coffee pot following his pioneering work with the Bavarian Army, where he improved the diet of the soldiers as well as their clothes.<ref name="Kleppner">{{cite journal |last1=Kleppner  |first1=Daniel |title=About Benjamin Thompson |journal=Physics Today |date=1 September 1992 |volume=45 |issue=9 |pages=9–11 |doi=10.1063/1.2809791 |bibcode=1992PhT....45i...9K |url=https://pubs.aip.org/physicstoday/article-abstract/45/9/9/407150/About-Benjamin-Thompson |access-date=9 July 2023 |author1-link=Kleppner }}</ref>

The [[Rumford fireplace]] created a sensation in London when he introduced the idea of restricting the chimney opening to increase the updraught, which was a much more efficient way to heat a room than earlier fireplaces. He and his workers modified fireplaces by inserting bricks into the hearth to make the side walls angled, and added a choke to the chimney to increase the speed of air going up the flue. The effect was to produce a streamlined air flow, so all the smoke would go up into the chimney rather than lingering and entering the room. It also had the effect of increasing the efficiency of the fire, and gave extra control of the rate of combustion of the fuel, whether wood or [[coal]]. Many fashionable London houses were modified to his instructions, and became smoke-free.<ref name="Kleppner" />

Thompson became a celebrity when news of his success spread. His work was also very profitable, and much imitated when he published his analysis of the way chimneys worked. In many ways, he was similar to [[Benjamin Franklin]], who also invented a new kind of heating stove.

The retention of heat was a recurring theme in his work, as he is also credited with the invention of [[thermal underwear]].<ref>[http://galileo.phys.virginia.edu/classes/152.mf1i.spring02/What%20is%20Heat.htm Prof. Michael Fowler of the University of Virginia, lecture notes], and ''[[Have I Got News For You]]'', first transmitted 16 December 2005, [[BBC1]].</ref>

===Industrial furnaces===
[[File:Rumford oven.svg|thumb| Cross section of a [[Rumford furnace]], with the fuel chamber at the left]]
Thompson also significantly improved the design of kilns used to produce [[quicklime]], and [[Rumford furnace]]s were soon being constructed throughout Europe. The key innovation involved separating the burning fuel from the limestone, so that the lime produced by the heat of the furnace was not contaminated by ash from the fire.

===Light and photometry===
Rumford worked in [[photometry (optics)|photometry]], the measurement of light.  He made a photometer and introduced the [[Candela#History|standard candle]], the predecessor of the [[candela]], as a unit of [[luminous intensity]].  His standard candle was made from the oil of a sperm whale, to rigid specifications.<ref>{{cite book
 | title = International Encyclopedia of Ergonomics and Human Factors
 | author = Waldemar Karwowski
 | publisher = CRC Press
 | year = 2006
 | isbn = 978-0-415-30430-6
 | page = 1478
 | url = https://books.google.com/books?id=tl5YAj10BcsC&q=benjamin-thompson++photometry+candle&pg=PA1478
 }}</ref> He also published studies of "illusory" or subjective complementary colours, induced by the shadows created by two lights, one white and one coloured; these observations were cited and generalized by [[Michel-Eugène Chevreul]] as his "law of simultaneous colour contrast" in 1839.<ref>{{cite book
 | title = The Complete Works of Count Rumford, Vol. 5
 | author = Benjamin Thompson, Count Rumford
 | publisher = American Academy of Arts and Sciences
 | year = 1876
 | url = https://books.google.com/books?id=udu4AAAAIAAJ&q=%22count+rumford%22+experiments+coloured+shadows&pg=PA51}}</ref>