Volume 1

The collected papers of Charles Darwin / edited by Paul H. Barrett ; with a foreword by Theodosius Dobzhansky.

  • Charles Darwin
Date:
1977
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Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: The collected papers of Charles Darwin / edited by Paul H. Barrett ; with a foreword by Theodosius Dobzhansky. Source: Wellcome Collection.

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    and Minchinmadom did not save the northern parts of Chiloe, though they occupy the same relative situation with regard to them, which Valdivia does to Villarica. Shall we then say, that Valdivia escaped so long the subterranean disturbances, some of which affected simulta neously regions north and south of it, solely on account of the greater strength of the crust in that part? This appears to me a cause quite inadequate; and the direct supposition is better, that as within the same period one part of the continent has been elevated more than another, so the lava has been propelled by the action of this force more powerfully towards some, than towards others, of the volcanic orifices which penetrate it. The secular shrinking of the earth's crust has been considered by many geologists a sufficient cause to account for the primary motive power of these subterranean disturbances; but how it can explain the slow elevation , not only of linear spaces, but of great continents, I cannot understand. With the same view, some highly important speculations have recently been advanced,—such as changes of pressure on the internal fluid mass, from the deposition of fresh sedimentary beds, and even the attraction of the planetary bodies on a sphere not solid throughout; but we can see that there must be many agents, modifying all such primary powers; and the furthest generalization, which the consideration of the volcanic phenomena described in this paper appears to lead to, is, that the configuration of the fluid surface of the earth's nucleus is subject to some change,—its cause completely unknown,—its action slow, intermittent, but irresistible. 1. [Read 7 March 1838.] Transactions of the Geological Society of London, 2d ser., pt. 3, 5 (1840):601-31.t 2. “Sketch of the Surveying Voyage of His Majesty's ships Adventure and Beagle. Vol. vi. Part II. p. 311. 3. Alexander Caldcleugh, An Account of the Great Earthquake Experienced in Chile on the 20th of February, 1835, with a Map, Philosophical Transactions of the Royal Society of London 126 (1836):21—26. t 4. Compendio de la Historia del Reyno de Chile, vol. i. p. 33. 5. Journal of Researches during the Voyage of the Beagle, p. 376. 6. This is mentioned by Dolomeu as a well-known fact during the Calabrian earthquake of 1783. Lyell's Principles of Geology (5th edition), vol. ii. p. 217. 7. Comptes Rendus, 1838. Séance Juin 11. 8. Voyages of the Adventure and Beagle, vol. ii. p. 418. 9. Comptes Rendus, October, 1838, p. 706. 10. Phil. Transact, for 1836. I likewise was informed by an intelligent person, that he had seen, from the plain near Talca, a volcano in the Cordillera in great activity on the night subsequent to the earthquake. 11. Journal of Science, Vol. xvii. 12. The Edinburgh Journal of Natural and Geographical Science, August 1830, p. 317. 13. Humboldt's Personal Narrative, Vol. iv. p. 21. English Translation.