the Contortions in Palaeozoic Strata. 61 



instability would continue. Meanwhile the waters would 

 arrange themselves, not parallel ^Yith the spheroidal crust, but 

 concentrically with the spherical mass within. Two large 

 oceans would thus accumulate near the poles, thus uncovering 

 the major part of the equatorial regions. Under this state 

 of things the earth's climate would increase in temperature. 

 Then, at last, as convulsions shattered the crust, or as the 

 simple force of gravitation caused the arch at the equator to 

 give way, and the pressure at the poles overcame the 

 resistance confining the molten matter within, would the 

 equilibrium be restored, water wordd again occupy the torrid 

 zone, and some portion at least of the polar oceans would be 

 left dry ground. 



I do not, however, think that the restoration of equilibrium 

 and exposm-e of the polar continents were the real causes of 

 the intense cold incidental to the glacial epoch. The hypo- 

 thetical hardly meet the real facts of the era, as made known 

 by observation. On the other hand, high northern and 

 southern latitudes appear to have been even more submerged 

 than at present. A glacial climate might result from con- 

 ditions somewhat the reverse of those described. That a 

 vast tract of land in equatorial regions should cause a 

 tropical climate to prevail in high latitudes it is necessary 

 that such land should be of a low, or at least of a moderately 

 low, level. Supposing an excess of land of gTeat altitude, 

 such as the land of the plateau of Mexico or of Thibet, to be 

 gathered round the equatorial regions, a very different state 

 of things would result. The equatorial regions might then 

 be covered by perpetual snow from excess of altitude, just as 

 are the plains of Nova Zembla by height of latitude. In 

 such, a case the southernly breezes of Europe would be as 

 chilly as those coming from the north, simply that both 

 would pass over equally frozen tracts of land. And this 

 mass of high table land might very naturally be looked for 

 under the conditions supposed. 



In the midst of the arctic climate so caused we may 

 imagine that the equilibrium is somewhat suddenly restored. 

 Tremendous currents would rush over what are now tem- 

 perate regions ; ample cause, it would seem, to account for 

 the glacial drift of both northern and southern hemispheres, 

 and for a very extensive destruction of animal and vegetable 

 forms. Could this be the moment of which the second verse 

 of Genesis speaks : " When the earth was without form and 

 void, and darkness was upon the face of the deep, and the 



