Penny Blood: Serial Sensation and Working-Class Entertainment — page 179: what you’re looking at

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

162 THE REVELATIONS OF (cH. XII. the greatest height of the mass of the Alps over the tunnel was 5307 feet. If we assume the temperature of the rock at the surface to be the freezing temperature, as in the case of S. Gothard, the above data give 7” =,},. And if we take the rate at a place on the sea-level to be ;4, and the tem- perature there 50° F., these data, when introduced into our equation, give e202 miles, ° | and @ the melting temperature = 2141° F. But if we take 7, as the rate at a place on the sea-level, then c= 29'1 miles, and a= 2612°F. The rates of increase of temperature have been found to | vary so much in different localities, that the rates at these two tunnels, though so nearly the same (and yet they are distant more than 130 miles), may differ somewhat from what might prove to be the average, were a greater number of moun- tains to be pierced. We may however feel assured that the rates determined represent pretty accurately the true rates at those places, because the amount of cover is so great, that the average is obtained for a great depth; a depth greater than has been reached in almost any other artificial excavation’. The results obtained in the present Chapter are decidedly corroborative of the views put forward in the tenth Chapter respecting the configuration of a section across a disturbed tract. For it is not easy to see on what hypothesis the conclusion regarding the downward convexity of the isogeotherms beneath a mountain can be explained, except on that of a protuberance of unmelted into melted matter. Indeed the existence of such roots to the mountain appears to be proved even more fully by the argument from temperature, than by that from geodesy. Again, the melting temperature at which we have arrived, without making any assumption about the temperature at which the rocks would melt, agrees very nearly with that of cast iron, which is about that which has been assumed by the older 1 An Artesian well is said to have been carried down to the depth of 5500 feet at Potsdam, Missouri. ‘Investor’s Guide,” Feb. 1881. COMiCOOokxS.conn @