Penny Blood: Serial Sensation and Working-Class Entertainment — page 54: what you’re looking at

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

cH.1Iv.] LATERAL PRESSURE, ITS AMOUNT. 3/7 The pressures 7’ and 7” being orthogonal cannot affect one another. Suppose then 7’ and r given. It follows that if r’ is increased or diminished 7” must be increased or diminished in the same proportion. Hence, if the curvature be diminished the pressure will be proportionately increased and vice versd. Hence there will be no greater tendency to compression where the curvature is greater, as about the equator, than where it is less, as about the poles, but the reverse. This answers an objec- tion which has been sometimes brought against the theory; although apart from the above reasoning it is scarcely likely that so small a difference of curvature as that referred to can have any appreciable consequence. It 1s inconceivable that such rock as we find at the surface of the earth could support so great a pressure as this without bending and breaking. Hence, if it be supposed possible that for a moment a shell of moderate thickness, say a few miles, should be self-supporting, and therefore exert no pressure upon that immediately beneath it, this state of things could not continue, and the outer shell would give way, and settle down upon the next stratum below it. We are not able however to estimate the downward pressure which will be exerted by it at any point upon the next lower stratum, because the lateral pressure 7’ might not be wholly relieved, but only partially so, and so to some extent help to support the shell. It is evident that in such a case the downward pressure would not be the same everywhere, the tilted rocks in some places supporting each other, and pressing with diminished weight upon the subjacent matter. If the rock were perfectly rigid 7 would have its full value, the shell would be self-supporting, and the vertical pressure on the next stratum would be nothing. If on the other hand the rock were fluid, such pressure would be that due to the depth + of the upper layer. Its actual value will be something inter- mediate, We will next make an attempt to estimate the lateral pres- sure at points within the earth, upon the supposition that the interior is solid, in order to see whether any stratum would be SS (CO) COMIC OOO