Penny Blood: Serial Sensation and Working-Class Entertainment — page 52: what you’re looking at

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

cu.Iv.] LATERAL PRESSURE, ITS AMOUNT. 35 denuded and levelled down, they now form mountain chains, in which the crumpling of the rocks 1s usually conspicuous. In other cases the tracts so elevated have been planed down by meteoric and marine action, afterwards covered by horizontal deposits, and re-elevated with greater or less secondary crump- ling, into the positions where ‘we now see them. That enormous force has been concerned in this crumpling of the hardest rock is obvious. Let us estimate its amount; premising that we make no assumption whatever regarding the condition of the interior of the globe nor the cause of contraction, but merely assume that it has shrunk away from a rigid upper crust. Th> problem is mathematically analogous to that of finding the tension of a flexible surface exposed to the pressure of a fluid. The form of the earth approaches very nearly to that of an oblate spheroid of revolution whose equatorial semiaxis (a) 18 20926184 feet and whose polar semiaxis (b) is 20855304 feet’. Its ellipticity as already stated is very nearly yt,. T 0’ Suppose PTQS to be a rectangular element of the crust, the four sides being equal and the thickness being 7, and let 2 p.. 33. 3—2 GONG oOo SS (CO) =a