Editorials. 



The doctrine of isostasy has been tentatively accepted by many 

 working geologists. It finds application in various departments 

 of geology, but nowhere more conspicuously than in glaciology. 

 Without passing judgment on the doctrine, and without attempt- 

 ing to restrict the field of its application, attention is called to 

 a misapprehension to which it has given rise. This misappre- 

 hension is widespread in the popular mind, and has even found 

 a foothold among those who have given attention to glacial 

 geology. 



Among the hypotheses which have gained more or less cur- 

 rency in explanation of the Pleistocene glacial climate, is that of 

 northward elevation. Whatever may be thought of this hypoth- 

 esis from a priori considerations, or whatever may be thought of 

 the evidence which is adduced in support of it, it has come to 

 have an appendix which we believe to be false. This appendix 

 seems not to have accompanied the hypothesis at the outset, and 

 some of the advocates of the hypothesis do not appear to have 

 given their sanction to the appendix, though their names are 

 sometimes connected with it. 



The hypothesis is, that northward elevation lowered the tem- 

 perature of the region affected to such an extent as to occasion the 

 accumulation of the Pleistocene ice-sheet. The appendix is, that 

 the elevated area sank under the weight of ice for which it was 

 responsible, until, as a result of the sinking thus effected, the cli- 

 mate was so far ameliorated as to bring about the melting of the 

 ice-sheet and the end of the glacial period. The appendix is 

 sometimes stated in milder form, the depression resulting from 

 the weight of the ice being looked upon as only one of the 

 causes which brought about the dissolution of the ice-sheet. 

 This view, both in its wider and in its more restricted sense, we 



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