Penny Blood: Serial Sensation and Working-Class Entertainment — page 186: what you’re looking at

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

CH, xuII.] AMOUNT OF COMPRESSION. 169 they have oscillated about their present positions, sometimes more extended on one side and sometimes on another; but that the great oceanic areas and the great continental areas have never, within times to which geological records go back, inter- changed places. If this be a true statement of the case, then it may be asserted that we know nothing about the geological constitution of the earth’s crust beneath the great oceans. We can affirm from observation that all land surfaces have been more or less subjected to compression, but we cannot affirm with any certainty that the same has been the case with the ocean bottoms. We appear in the present state of our know- ledge to be free to speculate upon this point. It is possible that the compression, which is so striking a feature in all true mountain ranges, and is by no means confined to them, may be a continental phenomenon only; that 18, may belong only to continents, and to islands which are geologically remnants of continents. The results at which we have arrived at the end of the last chapter tend to confirm this view, and to throw more than a doubt upon the doctrine that the abnormal eleva- tion, or radial excess, of the surface of dry land above the ocean floor is due altogether to compression. We need not how- ever decide at once upon this question, but, using general symbols in our reasoning, leave it for the present open. There are two ways in which compression may have acted to elevate the crust, supposed to rest on a fluid substratum. In _ the one the anticlinals would form ridges, whose sections would be cusp-like and-the subjacent fluid would rise into them. This hypothesis has been discussed in the ninth chapter, and has been shown not to accord with natural appearances. It is one however which has been more or less assumed in many geological writings’. The other is that developed in the tenth chapter, and shown in the eleventh and twelfth to be capable of explaining two classes of phenomena perfectly independent of each other, but which, it may be observed, would be absolutely reversed were the doctrine true, that the heavier and hot molten liquid rises into the anticlinals, 1 See Prof. A. de Lapparent, “L’Origine des inégalités de la Surface du Globe.” Revue des Questions Scientifics. Juillet, 1880. COLA @ (CO) NOO