170 Dr. C. Ricketts—Changes in the Earth’s Crust. 
Hutton, in his celebrated work, states that “the power of heat for 
the expansion of bodies is, so far as we know, unlimited; but, by the 
expansion of bodies placed under the strata at the bottom of the sea, 
the elevation of those strata may be effected; the question to be 
resolved regards the actual exertion of this power of expansion, how 
far it is to be concluded as having been employed in the production 
of this earth above the level of the sea. There has been exerted an 
extreme degree of heat below the strata formed at the bottom of the 
sea, and this is precisely the action of a power required for the 
elevation of those heated bodies into a higher place. Therefore, if 
there is no other way in which we may conceive this event to have 
been brought about, consistent with the present state of things, or 
what actually appears, we shall have a right to conclude that such 
had been the order of procedure in natural things, and that the strata 
formed at the bottom of the sea had been elevated, as well as con- 
solidated, by means of subterranean heat.” ! This coincides with the 
hypothesis advanced by Mr. Charles Babbage, nearly forty years 
subsequently, as a cause of disturbances of the earth’s crust; having 
been suggested to him by the changes of level, proved to have 
occurred within a comparatively short period, at the site of the 
Temple of Serapis, in the Bay of Naples.2. Mr. T. Mellard Reade 
considers “‘mountain ranges are ridgings up of the earth’s crust, 
which take place only in areas of great sedimentation. That the 
existing cause of the various horizontal and vertical strains, ending 
in the birth of a mountain-range, is the rise of the isogeotherms and 
consequent increase of temperature of the new sedimentaries, and 
that portion of the old crust they overlie. The tendency to expand 
horizontally is checked by the mass of the earth’s crust bounding the 
locally heated area, and is therefore forced to expend its energies 
within itself; hence arise foldings of lengthening strata, re-packing 
of beds, ridging up, and elevatory movements, which occur in 
varied forms according to the conditions present in each case.” * He 
thinks “ this mass of rock cannot expand laterally, for in that case it 
would displace the crust of the earth surrounding the affected area, 
nor downwards, for that would displace the foundations of the earth 
itself. It is only free to expand upwards.” * 
The expression, “if there is no other way,” indicates that Hutton 
felt some misgiving in supposing the elevation of the strata was due 
to the effect of expansion from the accession of subterranean heat, 
and that he suggested the theory for want of a better. With respect 
to this proposal, as advanced by Babbage, the Rev. O. Fisher 
remarks that ‘‘the heat conducted upwards into the new deposits 
must be abstracted from the couches beneath, so that there can be 
no absolute increase in the amount of the heat beneath the area in 
question, except such as is supplied laterally.”* It therefore follows, 
that there would be as great a diminution in size of the contiguous 
1 Theory of the Earth, by James Hutton, M.D., F.R S.E., 1795, vol.i. p. 128. 
Proc. Geol. Soc. vol. ii. p. 73; Quart. Journ. Geol. Soe. vol. iii. p. 186. 
Origin of Mountain Ranges, by T. Mellard Reade, C.E., F.G.S., p. 326. 
Pave 10. 
I’hysies of the Earth’s Crust, p. 82. 
o fF WO Dw 
