Treatise on natural philosophy : Vol 1. Part 2 / by Sir William Thomson and Peter Guthrie Tait.
- Date:
- 1883
Licence: Public Domain Mark
Credit: Treatise on natural philosophy : Vol 1. Part 2 / by Sir William Thomson and Peter Guthrie Tait. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![depth of this lava ocean to have been more than 50 or 100 miles; although we need not exclude the supposition of any greater depth, or of an entire globe of liquid. (u.) In the process of refrigeration, the fluid must [as I have remarked regarding the sun, in a recent article in Macmillan’s Magazine (March, 1862)*, and regarding the earth’s atmosphere, in a communication to the Literary and Philosophical Society of Manchester!] be brought by convection, to fulfil a definite law of “Co.n.vec.tive distribution of temperature which I have called “ convective equi- of tempera- librium of temperature.” That is to say, the temperatures at fined:de’ different parts in the interior must [in any great fluid mass which is kept well stirred] differ according to the different pres- sures by the difference of temperatures which any one portion of the liquid would present, if given at the temperature and pres- sure of any part, and then subjected to variation of pressure, but must have prevented from losing or gaining heat. The reason for this is proximately the extreme slowness of true thermal conduction; and the con- untKidi- sequently preponderating influence of great currents throughout commenced, a continuous fluid mass, in determining the distribution of tem- perature through the whole. (??.) The theimo-dynamic law connecting temperature and pressure in a fluid mass, not allowed to lose or gain heat, in- vestigated theoretically, and experimentally verified in the cases of air and water, by Dr Joule and myself*, shows, therefore, that the temperature in the liquid will increase from the surface downwards, if, as is most probably the case, the liquid contracts in cooling. On the other hand, if the liquid, like water near its * See Appendix E, below. . ^ Proceedin9s, Jan. 1862. “ On the Convective Equilibrium of Temperature m the Atmosphere.” £ Joule, “ On the Changes of Temperature produced by the Rarefaction and Condensation of Air,” Phil. Mag. 1845. Thomson, “On a Method for Deter- mining Experimentally the Heat evolved by the Compression of AirDynamical Theory of Heat, Part IV., Tram. R. S. E., Session 1850-51; and reprinted Phil. Mag. Joule and Thomson, “On the Thermal Effects of Fluids in Motion ” Trans. R. S. Loud., June 1853 and June 1854. Joule and Thomson “On the Alterations of Temperature accompanying Changes of Pressure in Fluids ” Proceedings R. S. Land., June 1857. These articles, except the first by Joule are all now republished in Vol. I. Arts. XLvm. and xmx. of Mathematical and Physical Papers, by Sir W. Thomson. VOL. II. 31](https://iiif.wellcomecollection.org/image/b21987312_0511.jp2/full/800%2C/0/default.jpg)
