WCP2150

[1]

Harlton

Cambridge

12 Aug 1879.

My dear Sir

Thank you for your letter¹ just received. The only part of it that I would remark upon is about glacial deposits, formed at great elevation ^{in tropical countries} being by subsidence submerged and covered with marine deposits. This is maintained virtually I think by all who look to changes of altitude to account for glacial phenomena. But my idea is that we cannot have marine glacial deposits except from glaciers which descend to the sea or an icefoot along the coast. Scratched boulders found in mountain regions soon lose all their scratches as they [2] are brought lower by the torrents. Any conceivable conditions which could at the present day deposit scratched stones from the Himalayan glaciers at the bottom of the ocean must involve sudden movements which would be quite inadmissable.

I trouble you with a paper of mine published long ago in the Geol Mag on a subject bearing both upon the question you are considering and also upon an article signed with your initials in the last number of Nature. Perhaps you never heard of my craze about what I call "trail". However there has is such a thing whatever it may be caused by. I converted Belt² to a belief in it & I think I have also converted Prestwich³ & Dawkins.⁴ [3] I suspect it to be glacial. But the point I would direct your attention to is that I believe it to be contemporaneous with the later glacial period in Scotland & that it is our indication here of the glacial period which succeeded the Scotch interglacial in which Elephants &c have been found. & that it was this period which cut off the pleistocene mammals with Palaeolithic man from the neolithic races.

As to the Palaeolithic men having been found by Skertchly⁵ beneath the boulder clay in Suffolk why (?). At any rate I am absolutely certain that he (not Skertchly, but Palaeolithic man) was later than the Chalky boulder clay in this country.

Skertchly showed me & Belt one of [4] the natives (near Botany Bay pit) on which he relied & I am sure what he called boulder clay was only what I call trail. But I believe he had localities which he relied on that I never saw. I knew that Jas Geikie⁶ believed in his view, but he only paid the district a week's visit. Ramsay⁷ believed also but Hughes,⁸ Prestwich, & I believe Evans⁹ are sceptical. Certainly I did not see the proof made out in what I saw during a day there with S. [Skertchly] & Belt.

I have been reading an article in the Taylor's scientific memoirs vol IV by Pouillet on radiation & he makes the temperature of space by a method totally different from Herschells -142^oC which is almost exactly the same as Herschell's.

Believe me | truly yours | Osmond Fisher¹⁰ [signature]

A R Wallace Esq.