On the temperature of the earth and sea, in reference to the theory of central heat : a lecture, delivered at the Royal Institution, February 20th, 1846, Lord de Mauley, V.P. in the chair / by Alfred S. Taylor.
- Alfred Swaine Taylor
- Date:
- 1846
Licence: Public Domain Mark
Credit: On the temperature of the earth and sea, in reference to the theory of central heat : a lecture, delivered at the Royal Institution, February 20th, 1846, Lord de Mauley, V.P. in the chair / by Alfred S. Taylor. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![vations yet made are tliose of Ermann and Baer, at Yakutsk, in Eastern Siberia. M. ]?aer ascertained that in diis desolate region the ground is thawed, during the short summer, only to the depth of three feet; below this, at all periods of the year, there is a hand of ice, or frozen soil, which has been perforated to the depth of 382 feet, hut without entirely traversing it. The solar influence, therefore, scarcely extends, in the course of seasons, beyond three feet from the surface. The invariable stratum must not he considered as a live, but rather as a zo7ie, varying from 2 to 40 or 50 feet in thickness. Its course below the surface is probably that of a curve, its depth being affected by many local circumstances—such as the nature of the strata, the situation of the place, whether it be on a plain, on a mountain, or in a valley—in the midst of a vast continent, or in the vicinity of seas, lakes, and rivers. Whatever afiects the mean temperature of a place, must affect its posi- tion. The influence of the strata in altering the position of this zone was observed by Captain Newbold in the tropics. He found a constant temperature to exist at four feet depth from the surface in clayey soils, but in order to obtain it in light sandy soils, it was necessary to go much deeper. Professor Forbes has undertaken some interesting experi- ments on the conducting power of the strata in the neighbour- hood of Edinburgh, but numerous observations are required in various latitudes before any satisfactory conclusions can be drawn on the subject: neither has the proportion between the quantity of solar heat radiated and that conducted downwards by the earth been correctly ascertained. One fact is certain, that when the earth is heated by the sun, that portion of heat which is not radiated or earned off by the evaporation of water from the soil—a condition which must cause the dissipation of an enormous quantity—is slowly transmitted to the interior; but when the quantity radiated exceeds the quantity received by the earth, as during the night or in the winter season, then a portion of that which has been conducted downwards, must again return to the surface and be dissipated. Hence there will be a suc- cession of waves of caloric descending or ascending, according to the temperature of the earth’s surface. 'I’he quantity that](https://iiif.wellcomecollection.org/image/b22356678_0010.jp2/full/800%2C/0/default.jpg)
