3 oo THE POPULAR SCIENCE MONTHLY. 



cumbent lava-cap to a depth, of two thousand feet ; secondly, by 

 the great denudation that lias taken place since they were depos- 

 ited, for they sometimes lie on the summits of mountains six 

 thousand feet high ; thirdly, by the fact that the Sierra Nevada 

 has been partly elevated since their formation." * 



As an important supplement to these discoveries of ancient 

 implements came sundry comparisons made by eminent physiolo- 



* For the general subject of investigations in British prehistoric remains, see especially 

 Boyd Dawkins, Early Man in Britain and his Place in the Tertiary Period, London, 1880. 

 For Boucher de Perthes's account of his discovery of the human jaw at Moulin Quignon, see 

 his Antiquites Celtiques et Antediluviennes, vol. iii, pp. 542 et seq., Appendix. For an ex- 

 cellent account of special investigations in the high terraces above the Thames, see J. 

 Allen Brown, F. G. S., Palaeolithic Man in Northwest Middlesex, London, 1887. For dis- 

 coveries in America, and the citation regarding them, see Wright, The Ice Age in North 

 America, New York, 1S89, chap. xxi. Very remarkable examples of these specimens from 

 the drift at Trenton may be seen in Prof. Abbott's collections at the University of Penn- 

 sylvania. For an admirable statement, see Prof. Henry W. Haynes, in Wright, as above. 

 For proofs of the vast antiquity of man upon the Pacific coast, cited in the text, see 

 Skertchley, F. G. S., in the Journal of the Anthropological Institute for 1887, p. 336; see 

 also Wallace, Darwinism, London, 1890, chap, xv; and for a summary, as cited, Laing, 

 Problems of the Future, London, 1889. For a striking summary of the evidence that 

 man lived before the last submergence of Britain, see Brown,, Palaeolithic Man in North- 

 west Middlesex, as above cited. For proofs that man existed in a period when the streams 

 were flowing hundreds of feet above their present level, see ibid., p. 33. As to the evi- 

 dence of the action of the sea and of glacial action in the Welsh bone caves after the 

 remains of extinct animals and weapons of human workmanship had been deposited, see 

 ibid., p. 198. For a good statement of the slowness of the submergence and emergence of 

 Great Britain, with an illustration from the rising of the shore of Finland, see ibid., pp. 47 

 48. As to the flint implements of Palaeolithic man in the high-terraced gravels throughout 

 the Thames Valley, associated with bones of the mammoth, woolly rhinoceros, etc., see 

 Brown, p. 31. For still more conclusive proofs that man inhabited North Wales before the 

 last submergence of the greater part of the British Islands to a depth of twelve hundred 

 to fourteen hundred feet, see ibid., pp. 199, 200. For maps showing the connection of the 

 British river system with that of the Continent, see Boyd Dawkins, Early Man in Britain, 

 London, 1880, pp. 18, 41, 73 ; also, Lyell, Antiquity of Man, chap. xiv. As to the long 

 continuance of the early Stone period, see James Geikie, The Great Ice Age, New York, 

 18S8, p. 402. As to the impossibility of the animals of arctic and torrid regions living 

 together or visiting the same place at different times in the same year, see Geikie, as 

 above, pp. 421 et scq. ; and for a conclusive argument that the animals of the period 

 assigned lived in England, not since, but before, the Glacial period, or in the intcrglacial 

 period, see ibid., p. 459. For a very candid statement by perhaps the foremost leader of 

 the theological rear-guard, admitting the insuperable difficulties presented by the Old Testa- 

 ment chronology as regards the creation and the deluge, see the Duke of Argyll's Primeval 

 Man, pp. 90-100, and especially pp. 93, 124. For a succinct statement on the general sub- 

 ject, see Laing, Problems of the Future, London, 1889, chapters v and vi. For discoveries 

 of prehistoric implements in India, see notes by Bruce Foote, F. G. S., in the British Jour- 

 nal of the Anthropological Institute for 1886 and 1887. For similar discoveries in South 

 Africa, see Gooch, in Journal of the Anthropological Institute of Great Britain and Ireland, 

 vol. xi, pp. 124 et seq. For proofs of the existence of Palaeolithic man in Egypt, see Mook, 

 Haynes, Pitt-Rivers, and others, cited at length in the next chapter. For the corroborative 

 and concurrent testimony of ethnology, philology, and history to the vast antiquity of man, 

 see Tylor, Anthropology, chap. i. 



