Published online by Cambridge University Press: 01 May 2009
The voyage of the “Beagle ” in 1831–6 was not only the starting-point of Charles Darwin's scientific career, but also, and more particularly, it laid the foundation for the whole of his geological work, as embodied in the well-known series of volumes. The collections which, he gathered during that prolonged voyage of exploration have therefore no small interest of a historical and sentimental kind. It is believed that they possess also a certain intrinsic value; inasmuch as an examination of these original specimens, with the advantages conferred by modern petrographical methods, may sometimes help towards a better understanding of the recorded observations. Owing to his choice of plain language in preference to the now antiquated terminology of his time, Darwin is seldom obscure to a modern reader; but his characterization of the ‘igneous rocks which he observed is necessarily crude and vague. Not a few passages may be considerably elucidated by merely indicating the nature of the rocks which are designated by such old-fashioned comprehensive names as ‘porphyry,’ ‘greenstone,’ and ‘basalt.’
page 100 note 1 “Journal and Remarks,” 1839; 2nd edition, entitled “Journal of Researches … during the Voyage of H.M.S. ‘Beagle’ …,” 1845. “The Structure and Distribution of Coral Reefs,” 1842. “Geological Observations on the Volcanic Islands …,” 1844. “Geological Observations on South America …,” 1846.
page 101 note 1 Doelter, C.: “Die Vulcane der Capverden und ihre Producte,” Graz, 1882. A few rocks collected by Doelter have been described by Fr. Eigel: Tscherm. Min. Petr. Mitth. (2), vol. xi (1889), pp. 91–104.Google Scholar There are also some earlier notes by A. Stelzner: Berg. u. Hütt. Zeit., vol. xxiv, p. 47.
page 102 note 1 The common English spelling is here adopted. Darwin writes the name ‘St. Jago,’ and Doelter uses the Portuguese form ‘S. Thiago.’
page 103 note 1 ‘Flagstaff Hill’ in Catalogue; ‘Mte. Facho’ according to Doelter.
page 105 note 1 Op. cit., pp. 88–91, with chemical analyses. The word ‘nephelinarmen’ at the beginning of the description should be ‘nephelinreichen.’
page 106 note 1 A like question has been raised by Washington with reference to the augite-grains in many hornblende-andesites: Journ. Geol., vol. iv (1896), pp. 273–278.