[13] See also S. Günther, Handbuch der mathematischen Geographie (Stuttgart, 1890).
[14] “On the Height of the Land and the Depth of the Ocean,” Scot. Geog. Mag. iv. (1888), p. 1. Estimates had been made previously by Humboldt, De Lapparent, H. Wagner, and subsequently by Penck and Heiderich, and for the oceans by Karstens.
[15] Petermanns Mitteilungen, xxv. (1889), p. 17.
[16] Proc. Roy. Soc. Edin. xvii. (1890) p. 185.
[17] Comptes rendus Acad. Sci. (Paris, 1890), vol. iii. p. 994.
[18] “Areal und mittlere Erhebung der Landflächen sowie der Erdkruste” in Gerland’s Beiträge zur Geophysik, ii. (1895) p. 667. See also Nature, 54 (1896), p. 112.
[19] Petermanns Mitteilungen, xxxv. (1889) p. 19.
[20] The areas of the continental shelf and lowlands are approximately equal, and it is an interesting circumstance that, taken as a whole, the actual coast-line comes just midway on the most nearly level belt of the earth’s surface, excepting the ocean floor. The configuration of the continental slope has been treated in detail by Nansen in Scientific Results of Norwegian North Polar Expedition, vol. iv. (1904), where full references to the literature of the subject will be found.
[21] British Association Report (Edinburgh, 1892), p. 699.
[22] Das Antlitz der Erde (4 vols., Leipzig, 1885, 1888, 1901). Translated under the editorship of E. de Margerie, with much additional matter, as La Face de la terre, vols. i. and ii. (Paris, 1897, 1900), and into English by Dr Hertha Sollas as The Face of the Earth, vols. i. and ii. (Oxford, 1904, 1906).