Penny Blood: Serial Sensation and Working-Class Entertainment — page 77: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

60 ELEVATIONS ON THE [cH. v1. Sir Wm. Thomson writes’, “The earth, although once all melted, or melted all round its surface’, did, in all probability, really become a solid at its melting temperature all through, or all through the outer layer, which had been melted; and not until the solidification was thus complete, or nearly so, did the surface begin to cool.” The conclusion at which he arrives on these grounds, respecting the present distribution of temperature, is. that the rate of increase from the surface downwards would be sensibly », of a degree F. per foot for the first 100,000 feet (19 miles) orso, Below that depth the rate of increase per foot would begin to diminish sensibly. At 400,000 feet (76 miles) it would have diminished to about 7}, of a degree per foot, and so on rapidly diminishing as shown in the curve. ‘‘Such is on the whole the most probable representation of the earth’s present temperature, at depths of from 100 feet, where the annual variations cease to be sensible, to 100 miles; below which the whole mass is, whether liquid or solid, probably at or very nearly at the proper melting temperature for the pressure at each depth”—that is to say, the cooling process not having at present reached so far, the state of the matter there cannot in any way influence the law of temperature in the strata above. © Having given this summary of Sir Wm. Thomson’s theory concerning the condition of the interior of the earth, we will now proceed to form an estimate of the average height of the elevations above the datum level (or of 2ke) which might be formed by the contraction of a globe so constituted. In order to do this, we must first of all estimate the com- pression, kle, corresponding to the present thickness & of the crust and to a length J upon the present surface, 1 «Nat..Phil.,” p. 722. ? Dr Sterry Hunt supports the latter view. ‘‘ American Journal of Science,” Vol. v. p. 264,3rd series, 1873. : COMICHNOOKS. COM .