Penny Blood: Serial Sensation and Working-Class Entertainment — page 165: what you’re looking at

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

148 THE REVELATIONS OF THE PLUMB-LINE. (cu. x1. distance, where the positive attraction of the mass 4 would have produced the effect n”. The whole effect, by the same ~ 8 3 formula, will be n’ x a ,orn x (1 — LB > and as in this case the fraction — is not very nearly equal to 1, there may be a considerable residual disturbing attraction. But even here, and however near to the mountains the station D may be, the real disturbing attraction will be less than that found by computing the attraction of the table-land alone.” The extreme felicity of the above explanation of a remark- 4 able phenomenon and the lucidity with which it is stated must i be sufficient apology for the length of the extract. One remark | more must be added because it is very pertinent to the subject ‘and reasoning of the preceding chapter. ‘It is supposed that the crust is floatmg in a state of equilibrium. But in our entire ignorance of the modus operandi of the forces which have raised submarine strata to the tops of high mountains, we cannot msist on this as absolutely true. We know (from the reasoning above) that it will be so to the limit of breakage of the table- Jands, but within those limits there may be some range of con- ditions either way*.” We believe however that since this passage was written geology has made some advance towards explaining the modus operand: of the elevatory forces; but the ‘proviso respecting the limits of breakage of the rocks 1s of great importance and must not be forgotten. Archdeacon Pratt replied to the Astronomer Royal’s paper three years later*. He brought against the explanation proposed three objections, not one of which appears in the present state of our knowledge to be of weight®. (1) It supposes the thickness of the earth’s solid crust to be considerably smaller than Mr Hopkins concluded it to be. This objection has been disposed of*. (2) It assumes that the crust is lighter than the fluid on which it rests, whereas in becoming solid we should expect it to 1 Loc. cit. p. 104. 2 <‘On the Deflection of the Plumb-line in India, &.”” Phil. Trans. Royal Soc., Vol. 149, p. 745. 3 Ibid. p. 747. 4p. 22. commiclsoolkks