[Footnote 75: Mantell, Wonders of Geology, Lecture IV., Fossils of the British Museum, chapter V.; see, also, Medals of Creation, and Fossils of the South Downs, by the same Author.] [Footnote 76: Owen’s Palæontology, pp. 200-9; Buckland, Bridgewater Treatise, vol. i., pp. 168-186; Mantell, Wonders of Geology, pp. 576-581; Lyell, Elements of Geology, pp. 420-425; Jukes, Manual of Geology, pp. 598-599.] [Footnote 77: Buckland’s Bridgewater Treatise, vol. i., pp. 202-14; Owen’s Palæontology, 223-232.] [Footnote 78: Buckland, Bridgewater Treatise, vol. i., pp. 139-164; Owen’s Palæontology, pp. 390-2; Mantell, Wonders of Geology, pp. 166-9; Fossils of the British Museum, pp. 465-480; The English Cyclopædia, Natural History Division, Article, Megatheridæ.] [Footnote 79: Lyell, Elements of Geology, p. 4.] [Footnote 80: Wonders of Geology, p. 400.] [Footnote 81: See Lyell, Principles of Geology, vol. i., p. 31, who refers to Da Vinci’s MSS. now in the Library of the Institute of France.] [Footnote 82: See Lyell, Elements of Geology, pp. 94-96; Principles of Geology, p. 116; Jukes, Manual of Geology, pp. 410, 411.] [Footnote 83: Elements of Geology, p. 95.] [Footnote 84: Lyell, Principles of Geology, vol. i., p. 115.] [Footnote 85: Lyell, Elements of Geology, p. 100.] [Footnote 86: Principles of Geology, vol. i., p. 312.] [Footnote 87: Ib. 313.] [Footnote 88: Principles of Geology, vol. i., pp. 321, 322.] [Footnote 89: Familiar Lectures on Scientific Subjects: London, 1867; pp. 9, 10.] [Footnote 90: It would be more strictly correct to say that the rate of increase varies considerably in different places, though the main fact is everywhere palpably apparent that the deeper we descend into the Earth the higher the temperature becomes. Sir Charles Lyell records a number of careful experiments made in England, France, Germany, and Italy, which seem to show that an increase of one degree Fahrenheit for every sixty-five feet of descent would represent pretty correctly the general average. See his Principles of Geology, vol. ii., pp. 205, 206.] [Footnote 91: See Sir John Herschel, Familiar Lectures on Scientific Subjects, pp. 26, 27.] [Footnote 92: See the elaborate work of Sir William Hamilton, entitled Campi Phlegraei, in which he gives a full account of the formation of Monte Nuovo, accompanied with colored plates. He has preserved two interesting narratives of the eruption written at the time by eye-witnesses. See also Lyell, Principles of Geology, vol. i., pp. 606-616.] [Footnote 93: Sir John Herschel, Familiar Lectures on Scientific Subjects, p. 34; see also Lyell, Principles of Geology, chap. xxvii.; Mantell, Wonders of Geology, pp. 872-4.] [Footnote 94: See Herschel, Familiar Lectures on Scientific Subjects, pp. 34-6. Lyell, Principles of Geology, vol. ii., pp. 104-6.] [Footnote 95: Familiar Lectures on Scientific Subjects, pp. 31, 32.] [Footnote 96: Principles of Geology, vol. ii., pp. 59, 60.]