Penny Blood: Serial Sensation and Working-Class Entertainment — page 25: what you’re looking at

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

8 ON UNDERGROUND TEMPERATURE. (cu. 1. on the supposition that the temperature of the rock in mass increases proportionally to the increase of depth, the tem- perature of the rock will be represented by a straight line, as AC. If, then, the temperature of the water in the bore-hole correctly gave the temperature of the rock, its temperature would be likewise represented by the same straight ine AC. But since it is affected by convection currents this cannot be the case ; for they tend to warm the upper portions of the column of water, and to cool the lower. Hence, so far as we have gone, the water in the upper part of the bore-hole will be warmer than the body of the rock, and in the lower part it will be cooler; and in our diagram we must draw a line to represent its temperature, more distant from OX in the upper part, and nearer to it in the lower. It need not, however, be a straight line, the law of increase of temperature being possibly altered. Suppose, then, DE to be this line, or the curve of temperature of the water on the supposition pow made. It will be seen that it must intersect the line AC. c x B FE There is a further consideration to be taken into account. If the bore-hole is nearly full of water, and of considerable dimensions, it will present a considerable surface to the atmo- sphere. At Sperenberg the water stood seven feet from the stage of the bore-pit, and the bore-hole was a foot in diameter. COMIC OOOKS.EO inn