More Letters of Charles Darwin Volume I [15]
209, 1833.), two males and one female. I find Chiloe is composed of lava and recent deposits. The lavas are curious from abounding in, or rather being in parts composed of pitchstone. If we go to Chiloe in the summer, I shall reap an entomological harvest. I suppose the Botany both there and in Chili is well-known.
I forgot to state that in the four cargoes of specimens there have been sent three square boxes, each containing four glass bottles. I mention this in case they should be stowed beneath geological specimens and thus escape your notice, perhaps some spirit may be wanted in them. If a box arrives from B. Ayres with a Megatherium head the other unnumbered specimens, be kind enough to tell me, as I have strong fears for its safety. We arrived here the day before yesterday; the views of the distant mountains are most sublime and the climate delightful; after our long cruise in the damp gloomy climates of the south, to breathe a clear dry air and feel honest warm sunshine, and eat good fresh roast beef must be the summum bonum of human life. I do not like the look of the rocks half so much as the beef, there is too much of those rather insipid ingredients, mica, quartz and feldspar. Our plans are at present undecided; there is a good deal of work to the south of Valparaiso and to the north an indefinite quantity. I look forward to every part with interest. I have sent you in this letter a sad dose of egotism, but recollect I look up to you as my father in Natural History, and a son may talk about himself to his father. In your paternal capacity as proproctor what a great deal of trouble you appear to have had. How turbulent Cambridge is become. Before this time it will have regained its tranquillity. I have a most schoolboy-like wish to be there, enjoying my holidays. It is a most comfortable reflection to me, that a ship being made of wood and iron, cannot last for ever, and therefore this voyage must have an end.
October 28th. This letter has been lying in my portfolio ever since July; I did not send it away because I did not think it worth the postage; it shall now go with a box of specimens. Shortly after arriving here I set out on a geological excursion, and had a very pleasant ramble about the base of the Andes. The whole country appears composed of breccias (and I imagine slates) which universally have been modified and oftentimes completely altered by the action of fire. The varieties of porphyry thus produced are endless, but nowhere have I yet met with rocks which have flowed in a stream; dykes of greenstone are very numerous. Modern volcanic action is entirely shut up in the very central parts (which cannot now be reached on account of the snow) of the Cordilleras. In the south of the R. Maypu I examined the Tertiary plains, already partially described by M. Gay. (5/3. "Rapport fait a l'Academie Royale des Sciences, sur les Travaux Geologiques de M. Gay," by Alex. Brongniart ("Ann. Sci. Nat." Volume XXVIII., page 394, 1833.) The fossil shells appear to me to be far more different from the recent ones than in the great Patagonian formation; it will be curious if an Eocene and Miocene (recent there is abundance of) could be proved to exist in S. America as well as in Europe. I have been much interested by finding abundance of recent shells at an elevation of 1,300 feet; the country in many places is scattered over with shells but these are all littoral ones. So that I suppose the 1,300 feet elevation must be owing to a succession of small elevations such as in 1822. With these certain proofs of the recent residence of the ocean over all the lower parts of Chili, the outline of every view and the form of each valley possesses a high interest. Has the action of running water or the sea formed this deep ravine? was a question which often arose in my mind and generally was answered by finding a bed of recent shells at the bottom. I have not sufficient arguments, but I do not believe that more than a small fraction of the height of the Andes has been formed within the Tertiary
I forgot to state that in the four cargoes of specimens there have been sent three square boxes, each containing four glass bottles. I mention this in case they should be stowed beneath geological specimens and thus escape your notice, perhaps some spirit may be wanted in them. If a box arrives from B. Ayres with a Megatherium head the other unnumbered specimens, be kind enough to tell me, as I have strong fears for its safety. We arrived here the day before yesterday; the views of the distant mountains are most sublime and the climate delightful; after our long cruise in the damp gloomy climates of the south, to breathe a clear dry air and feel honest warm sunshine, and eat good fresh roast beef must be the summum bonum of human life. I do not like the look of the rocks half so much as the beef, there is too much of those rather insipid ingredients, mica, quartz and feldspar. Our plans are at present undecided; there is a good deal of work to the south of Valparaiso and to the north an indefinite quantity. I look forward to every part with interest. I have sent you in this letter a sad dose of egotism, but recollect I look up to you as my father in Natural History, and a son may talk about himself to his father. In your paternal capacity as proproctor what a great deal of trouble you appear to have had. How turbulent Cambridge is become. Before this time it will have regained its tranquillity. I have a most schoolboy-like wish to be there, enjoying my holidays. It is a most comfortable reflection to me, that a ship being made of wood and iron, cannot last for ever, and therefore this voyage must have an end.
October 28th. This letter has been lying in my portfolio ever since July; I did not send it away because I did not think it worth the postage; it shall now go with a box of specimens. Shortly after arriving here I set out on a geological excursion, and had a very pleasant ramble about the base of the Andes. The whole country appears composed of breccias (and I imagine slates) which universally have been modified and oftentimes completely altered by the action of fire. The varieties of porphyry thus produced are endless, but nowhere have I yet met with rocks which have flowed in a stream; dykes of greenstone are very numerous. Modern volcanic action is entirely shut up in the very central parts (which cannot now be reached on account of the snow) of the Cordilleras. In the south of the R. Maypu I examined the Tertiary plains, already partially described by M. Gay. (5/3. "Rapport fait a l'Academie Royale des Sciences, sur les Travaux Geologiques de M. Gay," by Alex. Brongniart ("Ann. Sci. Nat." Volume XXVIII., page 394, 1833.) The fossil shells appear to me to be far more different from the recent ones than in the great Patagonian formation; it will be curious if an Eocene and Miocene (recent there is abundance of) could be proved to exist in S. America as well as in Europe. I have been much interested by finding abundance of recent shells at an elevation of 1,300 feet; the country in many places is scattered over with shells but these are all littoral ones. So that I suppose the 1,300 feet elevation must be owing to a succession of small elevations such as in 1822. With these certain proofs of the recent residence of the ocean over all the lower parts of Chili, the outline of every view and the form of each valley possesses a high interest. Has the action of running water or the sea formed this deep ravine? was a question which often arose in my mind and generally was answered by finding a bed of recent shells at the bottom. I have not sufficient arguments, but I do not believe that more than a small fraction of the height of the Andes has been formed within the Tertiary