Penny Blood: Serial Sensation and Working-Class Entertainment — page 59: what you’re looking at

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

42 LATERAL PRESSURE, ITS AMOUNT. [cu. tv. 1 IP ‘ >=< T-—T a (5 — a > =<gp x the height of a column of rock represented by the ordinate of the curve. Represent P by the weight of a column of rock at the sur- face of height equal to z. Then P =gpz; where g, p are the values, at the surface, and are constant. And z=f(r) will be some curve whose ordinate will bear the same ratio to P which that of the above curve (1) does to the pressure with which we have to compare P. Now all we know about this curve z=f(r) is from the nature of the case, which shows that its ordinate is always positive, that it 1s zero when r =a, and does not become infinite between r=0 and r=a. Hence, comparing the two curves, they will have a point in common when r=a, y=0Q; and the ordinate of the latter (which represents P) will be greater than that of the former (it being negative) until they intersect, which they must do some- where between r= 0 and r= a. Hence, the inequality. shows that the lateral pressure within the earth becomes equal to that at the surface when r = a (as it ought to do): while for values of r less than a it is always greater than that at the surface, until some point is reached, which cannot be further from the centre than 2 of the radius, and is probably much nearer to it. There the curves will inter- sect and the lateral pressure within the earth will be equal to that at the surface. Afterwards it becomes smaller and even-— tually infinitely smaller. The inference from this is that no shell is likely to have suffi- cient strength to resist the crushing effects of lateral pressure unless it be at a very small distance from the centre. And hence the supposition made by some geologists that the internal strata will be able to sustain the superincumbent weight on account of their dome-shaped form seems on the whole untenable. The result of this will be that, even if the earth be solid, foldings and dislocations of the strata commencing at the surface, will be commiclsoolkks (CO)