378 Reviews — Life of Sir Joseph Prestuich. 



fact that man was a contemporary of the long extinct mammals 

 whose bones were found lying beside his flint weapons in beds of 

 undisturbed gravel, and further to show that the deposit of this 

 gravel, though refei'able to a comparatively late geological period, 

 must be older than the present configuration of the ground. 

 Prestwich lost no time in communicating the results of his 

 examination of the Abbeville region to the Royal Society. He 

 cautiously abstained from pronouncing on the antiquity of man,, 

 contenting himself with pointing out that though there could be no 

 doubt that man was contemporary with certain extinct forms of 

 elephant, rhinoceros, deer, and other animals, no evidence had yet 

 been obtained to show the chronological value of the interval that had 

 elapsed since the deposit of the gravels containing the worked flints. 

 He himself was at first inclined, not so much to throw the human 

 period indefinitely backward, as to bring down the period of the 

 extinct mammalia nearer to our own day, and to account for their 

 disappearance and for the modification of the superficial topography 

 by some sudden or rapid geological change, which, though transient, 

 was powerful enough to leave its memorial on the surface of the 

 land. As his investigations proceeded he felt the weight of evidence 

 continually augmenting in favour of the long lapse of time required 

 for the excavation of the valleys and for the production of the vast 

 changes in the configuration of the land since the accumulation 

 of the implement-bearing gravels. In his next great memoir, 

 published in 1864, he admitted that 'we must greatly extend our 

 present chronology with respect to the first existence of man ; but 

 that we should count by hundreds and thousands of yeai's is, I am 

 convinced, in the present state of the inquir}^ unsafe and premature V 

 In this valuable essay, the whole evidence of the valley-gravels and 

 of the gradual erosion of the valleys is marshalled with great skill, 

 and discussed with characteristic clearness and caution. In later 

 essays he admitted that man was living in Glacial or Post-Glacial 

 times, which came down approximately to within 10,000 or 12,000 

 years of our own day. 



"Thus it is to Prestwich, more than to any other geologist, that we 

 owe the establishment of the fact that man coexisted with a number 

 of now long extinct mammals, and that his advent on the earth 

 must be relegated to a far higher antiquity than that which had been 

 previously accepted. While he was engaged in the researches that 

 led to these results he at the same time greatly enlarged our 

 knowledge of the later phases of the Ice Age, particularly in the 

 river-valleys of the south of England and north-west of France. 

 The term 'Drift ' has been vaguely applied to a multifarious series 

 of superficial deposits, differing widely from each other in origin 

 and in age. Prestwich strenuously contended for the local origin of 

 the gravels in which flint implements and mammalian remains occur 

 together. He showed that these accumulations unquestionably 

 belonged to the river-systems" within which they are found, that 

 they were fluviatile in origin, and were deposited by the streams 

 which still flow in the same valleys. He maintained, however, that 



