Penny Blood: Serial Sensation and Working-Class Entertainment — page 40: what you’re looking at

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

cH. 11.] CONDITION OF INTERIOR. 23 confirmed this conclusion, It does not however appear necessary that the earth should be absolutely solid from the surface to the centre in order to satisfy these requirements, May not the argument for rigidity drawn from the tides, after it has received that definite weight which proper observations (yet to be made) are expected to give it, be satisfied with a rigid nucleus of radius nearly approaching to that of the entire globe? Such tides as would be formed within the liquid substratum of the crust would not be of the nature of the tides, contemplated by Sir Wm. Thomson as affecting the entire spheroid, but more nearly ana- logous to the ocean tides; since they would involve a horizontal transference of fluid backwards -and forwards, and might be expected to be of small amplitude, owing to the viscosity of the substance and its confinement beneath the crust. However, even the modest requirement of a fluid substratum is refused. “But now thrice to slay the slain. Suppose the earth this moment to be a thin crust of rock or metal resting on liquid matter. Its equilibrium would be unstable! And what of the upheavals and subsidences? They would be strikingly analogous to those of a ship that had been rammed ; one portion of crust up and another down, and then all down. I may say with almost perfect certainty that whatever may be the relative densities of rock, solid and melted, at or about the temperature of liquefaction, it is, I think, quite certain that cold solid rock is denser than hot melted rock; and no possible degree of rigidity in the crust could prevent 1t from breaking in pieces and sinking wholly below the liquid lava’.” However, in a note to an address before the Geological Society of Glasgow, 14 Feb. 1878, Sir W. Thomson wrote, “Since this address was delivered, some important experiments have been carried out, at the request of Dr Henry Muirhead, by Mr Joseph Whitley of Leeds. Huis experiments were made on iron, copper, and brass, and on whinstone and granite; and the general result hitherto arrived at seems to be, that these substances are less dense in the solid than in the liquid state at the melting temperature®.’ And D. Forbes stated that glass 1 Sectional Address to the British Association, 1876, 2 «Trans, Geol. Society of Glasgow,” Vol. v1. Pt. 1, p, 40. GONG oOo SS (CO)