Penny Blood: Serial Sensation and Working-Class Entertainment — page 62: what you’re looking at

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

~ CHAPTER V. ELEVATIONS AND DEPRESSIONS. Distinction between compression and contraction—Definition of datum levels— General geometrical relation between the compresston of a portion of the earth's crust and the elevations and depressions referred to the upper datum level resulting therefrom—The same extended to the whole surface of the globe— Modification of this relation if the globe ts supposed tu be wholly solid— Average height of all the elevations above the datum level upon the suppost- tion of solidity, expressed in terms of depth of sea and height of land, and of areas of the same—This average height of actual elevations estimated in Jeet. ‘ Ir was proved in the last chapter that the horizontal thrust, or force of compression, thrown into a stratum at the earth's surface, or into any stratum to a very considerable depth below the surface, by the shrinking away of the underlying parts would be abundantly sufficient to crush the strata so left un- supported ; and it was explained how this crushing 1s supposed to have given rise to mountain chains. , The object of the present chapter is to find a relation between the quantity of the matter elevated and the amount of compression to which its elevation has been due. It is necessary to distinguish between the terms “compression” and “contraction.” Contraction of the underlying rocks causes compression in the rocks above them. Of course contraction and compression may go on simultaneously in the same stratum. It may be compressed by the contraction of the rocks beneath it and it may contract by itself cooling, or by losing some portion of its constituent substance. But for the present we shall con- sider. that the stratum which is compressed does not at the COLA @ NOO (CO)