Penny Blood: Serial Sensation and Working-Class Entertainment — page 243: what you’re looking at

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

CHAPTER XVIII. MR MALLET’S THEORY OF VOLCANIC ENERGY. Early opinions regarding the seat of volcanic energy—Hopkins’ lava lakes— Mallet’s theory—Opposed to the results of the present work—His mode of estimating the temperature derivable from crushing rock—His results pub- lished in the ‘Phil. Trans.”—differ from those given in an earlier publica- tion—Latent heat of fusion—Localization of heat from crushing not possible —More favourable hypothesis suggested and considered—A pressure, the greatest obtainable on the hypothesis, incapable of causing volcanic phe- NOMENA. It has been taken for granted more than once in the preceding pages, that the seat of volcanic energy is situated in the fluid substratum, which we have endeavoured to prove must underlie the cooled crust of the earth. This is the natural supposition, and was formerly generally assumed by geologists. But when , Hopkins published his supposed proof of the great thickness of the earth’s crust, he was constrained to offer a fresh explanation of this class of phenomena. Hence his theory of subterraneous lakes of lava. When Sir Wm. Thomson corroborated Hopkins’ view, and carried it further to the extent of asserting the entire solidity of the globe as a whole, the old assumption concerning the universal distribution of fluid matter beneath the crust received a further blow. The theory of Hopkins’ lakes was permitted to stand, but it was felt to be so improbable, that physical geologists in general could not rest satisfied with that explanation. At this juncture Mr Mallet oublished his theory of volcanic energy’, which at the time of its publication was received with 1 «Phil, Trans. Royal Soc.’’ Vol. 163, p. 147. 1873. COLA @ NOOKS CON