From James Geikie to G. H. Darwin 20 November 1877

Dear Sir

Allow me to thank you very much for the copy of your valuable & instructive paper ""On the influence of geological changes on the earth's axis by rotation"", which I have read with much interest.

There are probably few geologists who will not agree with you that if during the glacial period the N. pole stood somewhere where Greenland now stands large regions in Europe and N. America would have been glaciated. My difficulty, however, is that we have no evidence of such extensive movements of elevation & subsidence at the time required as would be necessary to effect the required change in the position of the pole. Again—there is abundant evidence to show that the glacial period was not the period of continuous cold which geologists have generally believed, but consisted rather of an alternation of cold and genial periods. Does not this render your hypothesis, as far at least as the glacial Period is concerned, more unlikely still? It is extremely interesting, however, to know now that geological changes may have influenced the geographical position of the pole during the past; and in speculating upon the climatic conditions of Europe, for example, during the Carboniferous Period we shall need to bear your results in view.

I have mentioned the alternation of cold & warm climatic conditions that obtained during our glacial period— I should have added that this view of the glacial climate is not accepted by all geologists. The evidence seems to me to be strongly in its favour, and it is gathering almost every day. Prof. Ramsay and I found traces of this remarkable alternation at Gibraltar! An account of our observations will shortly be read to the Geol. Soc. & I will have much pleasure in sending you a copy of the paper.

Excuse this long letter, & pray accept again my thanks for the instruction which I have received from your paper

Yours truly | James Geikie