Penny Blood: Serial Sensation and Working-Class Entertainment — page 177: what you’re looking at

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

160 THE REVELATIONS OF [cH. XII. whence If we assume a value for the ratio , this expression gives the thickness of the crust at a place at the sea-level, where the surface temperature is b, and the rate r. The place ought not to be in the mountainous region, in order that the rate may not be affected by the additional thickness of crust beneath such a region. Let us now apply equation (4) to find the thickness of the earth’s crust at a place at the sea-level, from the data obtained from the St Gothard tunnel. In Table vu. of Dr Stapff’s paper’, the rate at the exact middle of the tunnel is not given, but from the plate which illustrates his “Re- partition de la Temperature” it can be found. The height of the mountain above the sea over the middle point is there seen to be 2839 metres, and the altitude. of the tunnel itself 1127 metres. The temperature of the rock in the tunnel is 30°8 C., and of the ground, at the summit of the mountain above, 0°C. Hence the rate is 298 degree C. per metre, which is nearly 4, degree F. per foot. We will first assume the rate at the place A at the sea-level to be 4 degree F. per foot, and the mean surface temperature there to be 50° F. Also if we take, as we have previously done, the ratio of p : o as that of granite to basalt, viz., 2°68 : 2°96, we find that Co o— for the values of our symbols, =10°57. Then, expressing the altitudes in feet, we have 1 » 51’ * ~ 102 J 102° 1 « Etude de ]’Influence de la Chaleur de l’Intérieur de la Terre, &c.” p. 7. See note, p. 154, COMICHDOOKS.COM | ee a