Volume Ii Part 13 (1/2)
I. Vulcanicity and Earth-movements.--II. Ice-action.--III. The Parallel Roads of Glen Roy.--IV. Coral Reefs, Fossil and Recent.--V. Cleavage and Foliation.--VI. Age of the World.--VII. Geological Action of Earthworms.--VIII. Miscellaneous.
2.IX.I. VULCANICITY AND EARTH-MOVEMENTS, 1840-1881.
LETTER 479. TO DAVID MILNE. 12, Upper Gower Street, Thursday [March]
20th [1840].
I much regret that I am unable to give you any information of the kind you desire. You must have misunderstood Mr. Lyell concerning the object of my paper. (479/1. ”On the Connexion of certain Volcanic Phenomena, and on the Formation of Mountain-chains and the Effects of Continental Elevations.” ”Trans. Geol. Soc.” Volume V., 1840, pages 601-32 [March 7th, 1838].) It is an account of the shock of February, 1835, in Chile, which is particularly interesting, as it ties most closely together volcanic eruptions and continental elevations. In that paper I notice a very remarkable coincidence in volcanic eruptions in S. America at very distant places. I have also drawn up some short tables showing, as it appears to me, that there are periods of unusually great volcanic activity affecting large portions of S. America. I have no record of any coincidences between shocks there and in Europe. Humboldt, by his table in the ”Pers. Narrative” (Volume IV., page 36, English Translation), seems to consider the elevation of Sabrina off the Azores as connected with S. American subterranean activity: this connection appears to be exceedingly vague. I have during the past year seen it stated that a severe shock in the northern parts of S. America coincided with one in Kamstchatka. Believing, then, that such coincidences are purely accidental, I neglected to take a note of the reference; but I believe the statement was somewhere in ”L'Inst.i.tut” for 1839. (479/2.
”L'Inst.i.tut, Journal General des Societes et Travaux Scientifiques de la France et de l'Etranger,” Tome VIII. page 412, Paris, 1840. In a note on some earthquakes in the province Maurienne it is stated that they occurred during a change in the weather, and at times when a south wind followed a north wind, etc.) I was myself anxious to see the list of the 1200 shocks alluded to by you, but I have not been able to find out that the list has been published. With respect to any coincidences you may discover between shocks in S. America and Europe, let me venture to suggest to you that it is probably a quite accurate statement that scarcely one hour in the year elapses in S. America without an accompanying shock in some part of that large continent. There are many regions in which earthquakes take place every three and four days; and after the severer shocks the ground trembles almost half-hourly for months. If, therefore, you had a list of the earthquakes of two or three of these districts, it is almost certain that some of them would coincide with those in Scotland, without any other connection than mere chance.
My paper will be published immediately in the ”Geological Transactions,”
and I will do myself the pleasure of sending you a copy in the course of (as I hope) a week or ten days. A large part of it is theoretical, and will be of little interest to you; but the account of the Concepcion shock of 1835 will, I think, be worth your perusal. I have understood from Mr. Lyell that you believe in some connection between the state of the weather and earthquakes. Under the very peculiar climate of Northern Chile, the belief of the inhabitants in such connection can hardly, in my opinion, be founded in error. It must possibly be worth your while to turn to pages 430-433 in my ”Journal of Researches during the Voyage of the 'Beagle',” where I have stated this circ.u.mstance. (479/3. ”Journal of Researches into the Natural History and Geology of the Countries visited during the Voyage of H.M.S. 'Beagle' round the World.” London, 1870, page 351.) On the hypothesis of the crust of the earth resting on fluid matter, would the influence of the moon (as indexed by the tides) affect the periods of the shocks, when the force which causes them is just balanced by the resistance of the solid crust? The fact you mention of the coincidence between the earthquakes of Calabria and Scotland appears most curious. Your paper will possess a high degree of interest to all geologists. I fancied that such uniformity of action, as seems here indicated, was probably confined to large continents, such as the Americas. How interesting a record of volcanic phenomena in Iceland would be, now that you are collecting accounts of every slight trembling in Scotland. I am astonished at their frequency in that quiet country, as any one would have called it. I wish it had been in my power to have contributed in any way to your researches on this most interesting subject.
LETTER 480. TO L. HORNER. Down, August 29th [1844].
I am greatly obliged for your kind note, and much pleased with its contents. If one-third of what you say be really true, and not the verdict of a partial judge (as from pleasant experience I much suspect), then should I be thoroughly well contented with my small volume which, small as it is, cost me much time. (480/1. ”Geological Observations on the Volcanic Islands visited during the Voyage of H.M.S. 'Beagle'”: London, 1844. A French translation has been made by Professor Renard of Ghent, and published by Reinwald of Paris in 1902.) The pleasure of observation amply repays itself: not so that of composition; and it requires the hope of some small degree of utility in the end to make up for the drudgery of altering bad English into sometimes a little better and sometimes worse. With respect to craters of elevation (480/2.
”Geological Observations,” pages 93-6.), I had no sooner printed off the few pages on that subject than I wished the whole erased. I utterly disbelieve in Von Buch and de Beaumont's views; but on the other hand, in the case of the Mauritius and St. Jago, I cannot, perhaps unphilosophically, persuade myself that they are merely the basal fragments of ordinary volcanoes; and therefore I thought I would suggest the notion of a slow circ.u.mferential elevation, the central part being left unelevated, owing to the force from below being spent and [relieved?] in eruptions. On this view, I do not consider these so-called craters of elevation as formed by the ejection of ashes, lava, etc., etc., but by a peculiar kind of elevation acting round and modified by a volcanic orifice. I wish I had left it all out; I trust that there are in other parts of the volume more facts and less theory.
The more I reflect on volcanoes, the more I appreciate the importance of E. de Beaumont's measurements (480/3. Elie de Beaumont's views are discussed by Sir Charles Lyell both in the ”Principles of Geology”
(Edition X., 1867, Volume I. pages 633 et seq.) and in the ”Elements of Geology” (Edition III., 1878, pages 495, 496). See also Darwin's ”Geological Observations,” Edition II., 1876, page 107.) (even if one does not believe them implicitly) of the natural inclination of lava-streams, and even more the importance of his view of the dikes, or unfilled fissures, in every volcanic mountain, being the proofs and measures of the stretching and consequent elevation which all such mountains must have undergone. I believe he thus unintentionally explains most of his cases of lava-streams being inclined at a greater angle than that at which they could have flowed.
But excuse this lengthy note, and once more let me thank you for the pleasure and encouragement you have given me--which, together with Lyell's never-failing kindness, will help me on with South America, and, as my books will not sell, I sometimes want such aid. I have been lately reading with care A. d'Orbigny's work on South America (480/4. ”Voyage dans l'Amerique Meridionale--execute pendant les annees 1826-33”: six volumes, Paris, 1835-43.), and I cannot say how forcibly impressed I am with the infinite superiority of the Lyellian school of Geology over the continental. I always feel as if my books came half out of Lyell's brain, and that I never acknowledge this sufficiently; nor do I know how I can without saying so in so many words--for I have always thought that the great merit of the ”Principles” was that it altered the whole tone of one's mind, and therefore that, when seeing a thing never seen by Lyell, one yet saw it partially through his eyes--it would have been in some respects better if I had done this less: but again excuse my long, and perhaps you will think presumptuous, discussion. Enclosed is a note from Emma to Mrs. Horner, to beg you, if you can, to give us the great pleasure of seeing you here. We are necessarily dull here, and can offer no amus.e.m.e.nts; but the weather is delightful, and if you could see how brightly the sun now s.h.i.+nes you would be tempted to come. Pray remember me most kindly to all your family, and beg of them to accept our proposal, and give us the pleasure of seeing them.
LETTER 481. TO C. LYELL. Down, [September, 1844].
I was glad to get your note, and wanted to hear about your work. I have been looking to see it advertised; it has been a long task. I had, before your return from Scotland, determined to come up and see you; but as I had nothing else to do in town, my courage has gradually eased off, more especially as I have not been very well lately. We get so many invitations here that we are grown quite dissipated, but my stomach has stood it so ill that we are going to have a month's holidays, and go nowhere.
The subject which I was most anxious to talk over with you I have settled, and having written sixty pages of my ”S. American Geology,” I am in pretty good heart, and am determined to have very little theory and only short descriptions. The two first chapters will, I think, be pretty good, on the great gravel terraces and plains of Patagonia and Chili and Peru.
I am astonished and grieved over D'Orbigny's nonsense of sudden elevations. (481/1. D'Orbigny's views are referred to by Lyell in chapter vii. of the ”Principles,” Volume I. page 131. ”This mud [i.e.
the Pampean mud] contains in it recent species of sh.e.l.ls, some of them proper to brackish water, and is believed by Mr. Darwin to be an estuary or delta deposit. M.A. D'Orbigny, however, has advanced an hypothesis...that the agitation and displacement of the waters of the ocean, caused by the elevation of the Andes, gave rise to a deluge, of which this Pampean mud, which reaches sometimes the height of 12,000 feet, is the result and monument.”) I must give you one of his cases: He finds an old beach 600 feet above sea. He finds STILL ATTACHED to the rocks at 300 feet six species of truly littoral sh.e.l.ls. He finds at 20 to 30 feet above sea an immense acc.u.mulation of chiefly littoral sh.e.l.ls.
He argues the whole 600 feet uplifted at one blow, because the attached sh.e.l.ls at 300 feet have not been displaced. Therefore when the sea formed a beach at 600 feet the present littoral sh.e.l.ls were attached to rocks at 300 feet depth, and these same sh.e.l.ls were acc.u.mulating by thousands at 600 feet.
Hear this, oh Forbes. Is it not monstrous for a professed conchologist?
This is a fair specimen of his reasoning.
One of his arguments against the Pampas being a slow deposit, is that mammifers are very seldom washed by rivers into the sea!
Because at 12,000 feet he finds the same kind of clay with that of the Pampas he never doubts that it is contemporaneous with the Pampas [debacle?] which accompanied the right royal salute of every volcano in the Cordillera. What a pity these Frenchmen do not catch hold of a comet, and return to the good old geological dramas of Burnett and Whiston. I shall keep out of controversy, and just give my own facts. It is enough to disgust one with Geology; though I have been much pleased with the frank, decided, though courteous manner with which D'Orbigny disputes my conclusions, given, unfortunately, without facts, and sometimes rashly, in my journal.
Enough of S. America. I wish you would ask Mr. Horner (for I forgot to do so, and am unwilling to trouble him again) whether he thinks there is too much detail (quite independent of the merits of the book) in my volcanic volume; as to know this would be of some real use to me. You could tell me when we meet after York, when I will come to town. I had intended being at York, but my courage has failed. I should much like to hear your lecture, but still more to read it, as I think reading is always better than hearing.
I am very glad you talk of a visit to us in the autumn if you can spare the time. I shall be truly glad to see Mrs. Lyell and yourself here; but I have scruples in asking any one--you know how dull we are here. Young Hooker (481/2. Sir J.D. Hooker.) talks of coming; I wish he might meet you,--he appears to me a most engaging young man.
I have been delighted with Prescott, of which I have read Volume I. at your recommendation; I have just been a good deal interested with W.
Taylor's (of Norwich) ”Life and Correspondence.”