Penny Blood: Serial Sensation and Working-Class Entertainment — page 292: what you’re looking at

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

CH. XX11.] SUMMARY. 275 ence of linear contraction equal to their depth in the matter beneath themselves and beneath the land. But in the course of our calculations it has appeared that the entire radial con- traction would not be equal to the depression of the ocean bed beneath the land surface. We have then sufficiently proved, that the contraction of a solid earth through mere cooling 1s not adequate to account for the inequalities of the surface ; and it also appears probable that the other alternative must be accepted likewise, because the ocean basins being regarded as inequalities, or depressions, of the surface, they cannot be directly accounted for by compression; either as depressing them, or relatively raising the continents. Still further, the distribution of land and water upon the globe, as Herschel has observed, proves the force by which the continents are sustained to be one of tumefaction, and is therefore a proof of the com- parative lightness of the materials of the terrestrial hemisphere ; so that an excess of density appears to be requisite to retain the water over such extensive areas as are occupied by the greater oceans. Well-known geological phenomena, which prove the insta- bility of the earth’s surface, also negative the hypothesis of solidity. Alternate elevation and depression have frequently affected the same areas. But especially the shifting of the crust towards a mountain-range, which is testified by the corrugation of the rocks of which it 1s formed, requires a more or less fluid substratum to admit of it. The sinking of areas such as deltas, and other regions of deposition, demands a like arrangement ; and in short, it appears that the crust, in the form in which it exists, must be in a condition of approximate hydrostatical equilibrium, such that any considerable addition of load will cause any region to sink, or any considerable amount denuded off an area will cause it to rise. VIII. If we admit that the cooled crust of the earth rests upon a fluid substratum, we cannot doubt that the fluidity is a consequence of its high temperature ; and it probably follows that volcanic eruptions arise from emanations from the sub- stratum gaining access to the surface. All volcanic eruptions are 18—2 COLA @ NOO (CO)