My dear Sir

I hope that you will forgive me for troubling you with a very long letter— But first allow me to tell you with what extreme pleasure and admiration I have just finished reading your “Great Ice Age”¹   It seems to me admirably done & most clear. Interesting as many chapters are in the history of the world I do not think that any one comes nearly to the glacial period or periods. Though I have steadily read much on the subject, your book makes the whole appear almost new to me.

I am now going to mention a small observation made by me two or three years ago near Southampton but not followed out as I have no strength for [illeg] excursions—² I need say nothing about the character of the drift there (which includes palæolithic celts) for you have described its essential features in a few words at p. 506— It covers the whole country, even plain-like surfaces, almost irrespective of the present outline of the land.

⁠⟨⁠possibly 1 sheet missing⁠⟩⁠³

The coarse stratification has sometimes been disturbed, I find that you allude “to the larger stones often standing on end”; and this is the point which struck me so much.⁴ Not only moderately sized angular stones, but small oval pebbles often stand vertically up, in a manner which I have never seen in ordinary gravel beds— This fact reminded me of what occurs near my home in the stiff red clay full of unworn flints over the Chalk which is no doubt the residue left undissolved by rain water— In this Clay flints as long & thin as my arm often stand perpendicularly up; and I have been told by the tank diggers that it is their “natural position”! I presume that this position may safely be attributed to the differential movement of parts of the red clay as it subsided very slowly from the dissolution of the underlying chalk; so that the flints arrange themselves in the lines of least resistance. The similar but less strongly marked arrangement of the stones in the drift near Southampton makes me suspect that it also must have slowly subsided; and the notion has crossed my mind that during the commencement & height of the Glacial period great beds of frozen snow accumulated over S. England, and that during the summer gravel & stones were washed from the higher land over its surface and in superficial channels. The larger streams may have cut right through the frozen snow and deposited gravel in lines at the bottom. But on each succeeding autumn when the running water failed, I imagine that the lines of drainage would have been filled up by blown snow afterwards congealed, & that owing to great surface accumulations of snow it would be a mere chance whether the drainage together with gravel & sand would follow the same lines during the next summer.

Thus as I apprehend alternate layers of frozen snow and drift in sheets & lines would ultimately have covered the country to a great thickness; with lines of drift probably deposited in various directions at the bottom by the larger streams— As the climate became warmer the lower beds of frozen snow would have melted with extreme slowness and the many irregular beds of interstratified drift would have sunk down with equal slowness; & during this movement the elongated pebbles would have arranged themselves more or less vertically—

The drift would also have been deposited almost irrespective of the outline of the underlying land. When I viewed the Country I could not persuade myself that any flood however great, could have deposited such coarse gravel over the almost level platforms between the valleys. My view differs from that of Holst (p. 415.) of which I had never heard as his relates to channels cut through glaciers, and mine to beds of drift interstratified with frozen snow where no glaciers existed⁵   The upshot of this long letter is to ask you to keep my notion in your head and look out for upright pebbles in any lowland country which you may examine, where glaciers have not existed. Or if you think the notion deserves any further thought but not otherwise to tell anyone of it, for instance M^r. Skertchly who is examining such districts⁶

Pray forgive me for writing so long a letter and again thanking you for the great pleasure derived from your book. | I remain | Yours very faithfully | Ch. Darwin—

I hope what I have written may be intelligible for as you will see, I have taken no pains on the style.

P.S. You speak in the early part of your book of the Glacier theory having preceded that of icebergs; but I heard of the latter seven or eight years before a word was spoken in England of the extension of Ancient Glaciers—⁷

I am glad that you have read Blytt; his paper seemed to me a most important contribution to Botanical Geography. How curious that the same conclusions should have been arrived at by M^r Skertchly, who seems to be a first rate observer; and this implies as I always think a sound theoriser—⁸

I have told my publisher to send you in two or three days a copy (2^nd Edit) of my Geological work during voyage of Beagle— The sole point which would perhaps interest you is about the step-like plains of Patagonia

For many years past I have had fearful misgivings that it must have been the level of the sea, & not that of the land which has changed—⁹

I read a few months ago your very interesting life of Murchison   Though I have always thought that he ranked next to W Smith in the Classification of formations & though I knew how kindhearted, yet your book has raised him greatly in my respect notwithstanding his foibles & want of broad philosophical views—¹⁰

C.D.