 |
Please note that these pages are from our old (pre-2010) website; the presentation of these pages may now appear outdated and may not always comply with current accessibility guidelines. |
William Thomson, Lord Kelvin 1824-1907A web exhibition of manuscripts from the
collections
|
James Prestcott Joule, 1818-1889 |
|
|
|
"If [Thomson's] work in thermodynamics stood alone it would suffice to place his name as a natural philosopher beside that of Newton in its grasp of principles and generality of outlook; yet in this subject, in which his particular genius found scope in the knitting together and unification of fundamental laws, there will ever be associated with his name that of another worker, James Prestcott Joule." (S.P. Thompson: Life of William Thomson). A Manchester brewer and self-taught as a scientist, Joule established the principle of the interconvertibility of the various forms of energy, which is the first law of thermodynamics. As early as 1843, when he was 25, he determined the amount of energy required to produce a unit of heat, i.e. the mechanical equivalent of heat, and his name is given to the energy unit, the 'joule'. It was four years later, at the Oxford meeting of the British Association in 1847, that Thomson first met Joule. They soon became firm friends, working together, often in each other's houses, on a number of experiments, particularly the caloric effects of fluids in movement. |
|
Thomson also became the champion of the modest Joule, particularly in the major controversy of 1862 when the influential John Tyndall declared that Mayer was the originator of the concept of energy conservation. Two of the major results of their co-operation were the description of the Joule-Thomson effect (the fall in temperature when gas expands without doing external work) and Thomson's statement of the law of transformation, or the second law of thermodynamics. The Kelvin Papers contain over a hundred letters from Joule to Thomson covering the period 1853-1869, including many of the background letters to the Joule/Mayer controversy. |
|
To read the selection of letters in full, click on the thumbnails to view larger versions & then click on the 'back' button to return to this page (depending upon your browser, in viewing the larger version, you may have to click upon an additional button which will appear at the lower right corner to see the image at its largest size) |
14 June 1854 (MS Kelvin J101) "... We find that when 7500 cub inches of CO2 are mixed with 10 000 cubic inches of air the temperature falls about 0.2 degrees centigrade and… we intend trying more exact expts…" |
|
|
|
15 February 1855, from Thomson (MS Kelvin J109) "... I have just had an apparatus made for illustrating, in my lectures, your discovery that heat is generated by the magnetization or demagnetization of iron..." |
|
|
|
|
|
5 May 1857 (MS Kelvin J112) "... I thought that an experiment with a coiled wire would readily show whether the elasticity of metals altered with their temperature. I have made the experiment this day. . . I am not quite sure that what I have observed is new, but I always understood that a seeming contrary result had been observed viz that iron is made stronger by heat..." |
|
|
|
|
|
|
30 May 1865 (MS Kelvin J178) "I have constructed a rude galvanometer independent of terrestrial magnetism and tried it successfully today …" |
|
|
|
|
|
20 March 1867 (MS Kelvin J187) "... An affection has sprung up between me and my cousin you saw when last here. There are hindrances in the way so that nothing may come of it, but I cannot allow anything which has occupied much of my thoughts to be unknown to my dearest friend…" |
|
|
|
|
|
|
