Volume Ii Part 19 (2/2)
The parallel terraces are dealt with by Aga.s.siz, pages 236 et seq.) would be puzzled to block up Glen Gluoy and Kilfinnin by the same glacier, and then, moreover, the lake would have two outlets. With respect to the middle terrace of Glen Roy--seen by Chambers in the Spean (figured by Aga.s.siz, and seen by myself but not noticed, as I thought it might have been a sheep track)--it might yet have been formed on the ice-lake theory by two independent glaciers going across the Spean, but it is very improbable that two such immense ones should not have been united into one. Chambers, unfortunately, does not seem to have visited the head of the Spey, and I have written to propose joining funds and sending some young surveyor there. If my letter is published in the ”Scotsman,” how Buckland (523/2. Professor Buckland may be described as joint author, with Aga.s.siz, of the Glacier theory.), as I have foreseen, will crow over me: he will tell me he always knew that I was wrong, but now I shall have rather ridiculously to say, ”but I am all right again.”
I have been a good deal interested in Miller (523/3. Hugh Miller's ”First Impressions of England and its People,” London, 1847.), but I find it not quick reading, and Emma has hardly begun it yet. I rather wish the scenic descriptions were shorter, and that there was a little less geologic eloquence.
Lyell's picture now hangs over my chimneypiece, and uncommonly glad I am to have it, and thank you for it.
LETTER 524. TO C. LYELL. Down, September 6th [1861].
I think the enclosed is worth your reading. I am smashed to atoms about Glen Roy. My paper was one long gigantic blunder from beginning to end.
Eheu! Eheu! (524/1. See ”Life and Letters,” I., pages 68, 69, also pages 290, 291.)
LETTER 525. TO C. LYELL. Down, September 22nd [1861].
I have read Mr. Jamieson's last letter, like the former ones, with very great interest. (525/1. Mr. Jamieson visited Glen Roy in August 1861 and in July 1862. His paper ”On the Parallel Roads of Glen Roy, and their Place in the History of the Glacial Period,” was published in the ”Quarterly Journal of the Geological Society” in 1863, Volume XIX., page 235. His latest contribution to this subject was published in the ”Quarterly Journal,” Volume XLVIII., page 5, 1892.) What a problem you have in hand! It beats manufacturing new species all to bits. It would be a great personal consolation to me if Mr. J. can admit the sloping Spean terrace to be marine, and would remove one of my greatest difficulties--viz. the vast contrast of Welsh and Lochaber valleys. But then, as far as I dare trust my observations, the sloping terraces ran far up the Roy valley, so as to reach not far below the lower shelf. If the sloping fringes are marine and the shelves lacustrine, all I can say is that nature has laid a shameful trap to catch an unwary wretch. I suppose that I have underrated the power of lakes in producing pebbles; this, I think, ought to be well looked to. I was much struck in Wales on carefully comparing the glacial scratches under a lake (formed by a moraine and which must have existed since the Glacial epoch) and above water, and I could perceive NO difference. I believe I saw many such beds of good pebbles on level of lower shelf, which at the time I could not believe could have been found on sh.o.r.es of lake. The land-straits and little cliffs above them, to which I referred, were quite above the highest shelf; they may be of much more ancient date than the shelves.
Some terrace-like fringes at head of the Spey strike me as very suspicious. Mr. J. refers to absence of pebbles at considerable heights: he must remember that every storm, every deer, every hare which runs tends to roll pebbles down hill, and not one ever goes up again. I may mention that I particularly alluded to this on S. Ventanao (525/2.
”Geolog. Obs. on South America,” page 79. ”On the flanks of the mountains, at a height of 300 or 400 feet above the plain, there were a few small patches of conglomerate and breccia, firmly cemented by ferruginous matter to the abrupt and battered face of the quartz--traces being thus exhibited of ancient sea-action.”) in N. Patagonia, a great isolated rugged quartz-mountain 3,000 feet high, and I could find not one pebble except on one very small spot, where a ferruginous spring had firmly cemented a few to the face of mountain. If the Lochaber lakes had been formed by an ice-period posterior to the (marine?) sloping terraces in the Spean, would not Mr. J. have noticed gigantic moraines across the valley opposite the opening of Lake Treig? I go so far as not to like making the elevation of the land in Wales and Scotland considerably different with respect to the ice-period, and still more do I dislike it with respect to E. and W. Scotland. But I may be prejudiced by having been so long accustomed to the plains of Patagonia. But the equality of level (barring denudation) of even the Secondary formations in Britain, after so many ups and downs, always impresses my mind, that, except when the crust-cracks and mountains are formed, movements of elevation and subsidence are generally very equable.
But it is folly my scribbling thus. You have a grand problem, and heaven help you and Mr. Jamieson through it. It is out of my line nowadays, and above and beyond me.
LETTER 526. TO J.D. HOOKER. Down, September 28th [1861].
It is, I believe, true that Glen Roy shelves (I remember your Indian letter) were formed by glacial lakes. I persuaded Mr. Jamieson, an excellent observer, to go and observe them; and this is his result.
There are some great difficulties to be explained, but I presume this will ultimately be proved the truth...
LETTER 527. TO C. LYELL. Down, October 1st [1861].
Thank you for the most interesting correspondence. What a wonderful case that of Bedford. (527/1. No doubt this refers to the discovery of flint implements in the Valley of the Ouse, near Bedford, in 1861 (see Lyell's ”Antiquity of Man,” pages 163 et seq., 1863.) I thought the problem sufficiently perplexing before, but now it beats anything I ever heard of. Far from being able to give any hypothesis for any part, I cannot get the facts into my mind. What a capital observer and reasoner Mr.
Jamieson is. The only way that I can reconcile my memory of Lochaber with the state of the Welsh valleys is by imagining a great barrier, formed by a terminal moraine, at the mouth of the Spean, which the river had to cut slowly through, as it drained the lowest lake after the Glacial period. This would, I can suppose, account for the sloping terraces along the Spean. I further presume that sharp transverse moraines would not be formed under the waters of the lake, where the glacier came out of L. Treig and ab.u.t.ted against the opposite side of the valley. A nice mess I made of Glen Roy! I have no spare copy of my Welsh paper (527/2. ”Notes on the Effects produced by the Ancient Glaciers of Caernarvons.h.i.+re, and on the Boulders transported by Floating Ice,” ”Edinb. New Phil. Journ.” Volume x.x.xIII., page 352, 1842.); it would do you no good to lend it. I suppose I thought that there must have been floating ice on Moel Tryfan. I think it cannot be disputed that the last event in N. Wales was land-glaciers. I could not decide where the action of land-glaciers ceased and marine glacial action commenced at the mouths of the valleys.
What a wonderful case the Bedford case. Does not the N. American view of warmer or more equable period, after great Glacial period, become much more probable in Europe?
But I am very poorly to-day, and very stupid, and hate everybody and everything. One lives only to make blunders. I am going to write a little book for Murray on Orchids (527/3. ”On the Various Contrivances by which Orchids are Fertilised by Insects,” London, 1862.), and to-day I hate them worse than everything. So farewell, in a sweet frame of mind.
LETTER 528. TO C. LYELL. Down, October 14th [1861].
I return Jamieson's capital letter. I have no comments, except to say that he has removed all my difficulties, and that now and for evermore I give up and abominate Glen Roy and all its belongings. It certainly is a splendid case, and wonderful monument of the old Ice-period. You ought to give a woodcut. How many have blundered over those horrid shelves!
That was a capital paper by Jamieson in the last ”Geol. Journal.”
(528/1. ”On the Drift and Rolled Gravel of the North of Scotland,”
”Quart. Journ. Geol. Soc.” Volume XVI., page 347, 1860.) I was never before fully convinced of the land glacialisation of Scotland before, though Chambers tried hard to convince me.
I must say I differ rather about Ramsay's paper; perhaps he pushes it too far. (528/2. ”On the Glacial Origin of Certain Lakes, etc.” ”Quart.
Journ. Geol. Soc.” Volume XVIII., page 185. See Letter 503.) It struck me the more from remembering some years ago marvelling what could be the meaning of such a mult.i.tude of lakes in Friesland and other northern districts. Ramsay wrote to me, and I suggested that he ought to compare mountainous tropical regions with northern regions. I could not remember many lakes in any mountainous tropical country. When Tyndall talks of every valley in Switzerland being formed by glaciers, he seems to forget there are valleys in the tropics; and it is monstrous, in my opinion, the accounting for the Glacial period in the Alps by greater height of mountains, and their lessened height, if I understand, by glacial erosion. ”Ne sutor ultra crepidam,” I think, applies in this case to him. I am hard at work on ”Variation under Domestication.” (528/3.
Published 1868.)
P.S.--I am rather overwhelmed with letters at present, and it has just occurred to me that perhaps you will forward my note to Mr. Jamieson; as it will show that I entirely yield. I do believe every word in my Glen Roy paper is false.
LETTER 529. TO C. LYELL. Down, October 20th [1861].
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