Penny Blood: Serial Sensation and Working-Class Entertainment — page 39: what you’re looking at

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

22 CONDITION OF INTERIOR. (CH. 11. may be attacked in two ways. The first of these is by consider- ing what is the difference of effect that bodies exterior to it, namely the sun and moon, would have upon the motions of the earth in either case, and secondly by considering the sequence of events according to which a molten globe, such as the earth once was, may have passed into its present state. For the first, Mr Hopkins, in the Phil. Trans. for 1839-40- 42, investigated the consequences which, according to certain assumptions, would have resulted from the effect of internal fluidity upon the phenomenon of precession of the equinoxes, and he came to the conclusion that the solid crust of the earth could not be less than from 800 to 1000 miles thick. His argument was assailed by Delaunay’, but strongly sup- ported by Sir Wm. Thomson and Archdeacon Pratt: while General Barnard” believed that Hopkins’ result was vitiated by an over- sight. It is however scarcely worth while to consider this argu- ment further, because Sir Wm. Thomson has himself given up this particular reason against the doctrine of a fluid interior. “In- teresting in a dynamical point of view as Hopkins’ problem is, it cannot afford a decisive argument against the earth’s interior liquidity’.” To this change of opinion he was led by a conver- sation with Prof. Newcomb in America. But there is another manner in which the sun and moon affect terrestrial motion ; namely by raising the ocean tides, If the earth were not exceedingly rigid the globe itself would be raised in tides as well as the water which covers it, and since the measurable tide is the distance between the floor of the ocean and the surface of the sea, it is plain that if the floor of the ocean was drawn up along with the surface of the sea, the tide would be thereby diminished. Sir Wm. Thomson says: “The solid crust would yield so freely to the deforming influence of the sun and moon, that it would simply carry the waters of the ocean up and down with it, and there would be no sensible tidal rise and fall of water relatively to land*.” Mr George Darwin has 1 ‘*Geol. Mag.” Vol. v. p. 507. 2 ‘« Problems of Rotary Motion.” ‘‘ Smithsonian Contributions,” No. 240, New Addendum, p. 42. Vol. xrx. 1871. 2 Sectional Address to British Association, 1876, 4 Thid. COMICOOOLKS @ (CO)