WCP2957

[1]¹

173, Woodstock Road,

Oxford.

7 July 1909.

Dear D^r. Wallace,

Thank you for your extremely kind letter.² I am extremely proud if any poor attempt of mine can prove of any interest to you. The address was written under strict limitations as to time so that there are numerous oversights in it, one of the most glaring being the omission of any reference to your work. This however is so thoroughly well known amongst geologists that they are less likely to overlook it than I.

[2] I do not know however of any evidence of a primitive archipelago stage in the history of the earth, nor of any a priori reasons in favour of it. I should personally be inclined to suppose that both land & water formed originally more connected masses than they do at the present day. I am also uncertain as to the prevalence of more uniform climates in the earlier days, we have good evidence of glacial episodes in the pre-Cambrian of S. Africa, perhaps also in Scandinavia, and of³ [3] wide spread glacial action in the Cambrian of China & South Australia.

As to the production of heat I fear we have more now on our hands than we know what to do with. Strutt⁴ & Joly's⁵ work is really very embarrassing, perhaps therefore so much the better, it so completely disorganizes all our established conceptions on this subject that it seems to me we must make a fresh start. I presume you have read Joly's work ^book on Radium in Geology?⁶

[4] The difficulty in estimating time from the stratigraphical succession seems to me to lie in the existence of discontinuity. We know of several mighty breaks in this series, but there are also others, possibly very numerous, the significance of which is less known. This however is a promising subject for investigation: & how much can be learnt from the sediments is shown by De Geer's⁷ work on the Pleistocene of Scandinavia to which I ought to have referred in my address, but did not.

Believe me Dear D^r. Wallace | very sincerely yours | W. J. Sollas⁸ [signature]