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.

  • Taylor, Alfred Swaine, 1806-1880.
Date:
1846
Catalogue details

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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    s'phere is hollow—that, in short, the earth is a mere shell; and a third, that the nucleus of the globe is solid, and that it is gradually cooling down to the temperature of space. It is not my intention to occupy your time in discussing the ingenious arguments which have been adduced in support of these conflicting views; hut rather to direct your attention to certain well-ascertained facts, and leave'you to draw your own conclu- sions respecting them. I am aware that some of those whom I now have the honour of addressing, are well acquainted with the details into wliich I am about to enter; hut I would here beg to observe, that in bringing forward this subject for a lecture before the members of the Koyal Institution, my view has been, not so much to seek for novelty, as to combine in a slight general sketch some well-ascertained facts. It is well known from the results of numerous experiments, and from astronomical observations, that the Earth has the form of an oblate spheroid, or of a sphere some-what flattened at the poles. Its greatest diameter may be taken, in round numbers, at about 8000 miles. The diflerence between the polar and equatorial diameters is about 20 miles—the polar diameter being the the lesser of the two. This diflerence is about equal to the l-30Gth part of the earth’s diameter, or, the polar axis being 30-5, the equatorial axis is 306. In a globe of 30 inches in diarneter, the difference in the polar axis would, therefore, bo (36 306) nearly O’12 inch, or about one-eighth of an inch, a quantity not perceptible to the eye. The earth is surrounded by an atmosphere, a mLxture of gases, or an aerial ocean, extending to a distance of 45 miles from the surface. This distance is partly calculated from the known laws of the refraction of light, and from the progressive decrease in the density of air by elevation. At 45 miles above the level of the sea, the air has only 1-12000th part of the density which it has upon the surface ; and as this is equal to a good artificial vacuum, it is there considered to terminate. This may appear an amazing thickness, but it dwindles to a small ring, when compared with the earth s diameter, of which it forms only the 1 -177th part. In this diametric section, in wluch