Penny Blood: Serial Sensation and Working-Class Entertainment — page 85: what you’re looking at

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

68 | ELEVATIONS ON THE — [cH. v1. at'7000° took place will have been 100,000,000 years, whence as already stated, a = 2./xt = 400,000 feet, or about 80 miles, And b=—— = 7900". 4 Jar In order to fix upon a value of EZ, the coefficient of contrac- tion for 1° F., reference is made to some experiments on a large scale conducted by Mr Mallet*. And upon reducing his results we find for slag from an iron furnace LH =-‘0000215* whence = the linear contraction = ‘000007; which does not differ more than might be expected from the estimates made at much lower temperatures for rock by Mr Adie’. If we take the earth’s mean radius at 20,902,520 feet, we obtain as the final result for the two first terms, 286 feet. The third term gives the effect of the contraction of the entire volume of the sphere, from the depth 2a to the centre, in corrugating the crust to the depth 2a, on the supposition that the contraction continues to the centre as great as it is at 1 “Phil. Trans. Royal Soc.,” Vol. 163, p. 201. See also ‘‘ Nature,” Vol. xxr1. p. 266. 2 To obtain the coefficient of contraction for 1°F. from Mr Mallet’s ex- periments. The cones of slag began to solidify when the containing iron cones were at 450°F. At that time the mean contents -of the cones was 8231-9229 cubic inches, and the volume of the slag when measured at 53°F. was 7700-2303 cubic inches. The slag entered the cones at a temperature of 3680°. By Mr Mallet’s estimate, founded on the time in which solidification com- menced, the solidification commenced at about ‘‘3062°, or say 3000° F.” Hence am number of degrees through which the temperature fell was 3062° — 63° = 3009°. We have therefore to determine EF, the coefficient of cubical contraction between incipient consolidation and 53°F, 7700 = 8232 (1 — £3009) ; * E=-0000215, and = = 0000071. 3 The mean of Mr Adie’s six results for the coefficient of expansion is ‘0000057. ‘¢Trans. Roy. Soc. Edin.,” Vol. xm. p. 370. See also ‘‘Geol. Mag.,” Vol. x. p. 260, commiclsoolkks (CO)