Edward Grcenhj — Post- Glacial Time in Egypt. 537 



gravels. In suggesting that it belongs to the period of the Wilbraham- 

 Quy gravels I do not desire to hint at their strict contemporaneity. 

 I would only submit that if separable from the plateau gravels the 

 evidence is in favour of its being grouped with tlie deposits referred 

 to by the Geological Surveyors rather under the title " Gravels of the 

 Ancient River System " than to those which they describe under the 

 heading of " Gravels of the Present River System." 



EXPLANATION OF PLATE XXXL 



Palseolithic Implement from near Hildersham, Cambridgeshire. The view of the 

 face, Fig. 1, is about f uat. size ; that of the edge, Fig. 2, about f nat. size ; 

 Fig. 3, ideal section. 



III. — Post-Glacial Time and Ancient Egypt. 

 By Edward Greenly, F.G.S. 



PERPLEXING as are all problems connected with geological time, 

 there has naturally appeared much more hope of determining the 

 length of the period that has elapsed since the close of the great 

 Glacial episode in the Northern Hemisphere, the period in which, 

 indeed, we may be said to live, seeing that many processes that can 

 be observed in action may be supposed to have gone on without 

 interruption from the disappearance of the ice to the present day. 

 It has proved, however, scarcely less difficult than the other problems 

 of geological chronology. Many methods have been applied, and the 

 results reached have been hardly less varied than the methods. 



In the last few years a group of investigators, applying anew the 

 method of Bakewell, Lyell, and others, the measurement, that is, of 

 the rate of recession of Niagara and other waterfalls, have arrived 

 at estimates that are surprisingly short, some of them even restricting 

 Post-Glacial time to not more than about 6000 years. 



Has it been perceived, however, that such estimates as these must 

 of necessity bring the matter into touch with another series of 

 chronological measurements, derived from totally distinct data, and 

 by a quite independent group of investigators ? 



At a time when all the mountain-ranges of the northern shores 

 of the Mediterranean basin were heavily glaciated, when the Alps sent 

 out gigantic glaciers into the Plain of Lombardy, it is certain that 

 the whole Mediterranean region must have been, in varying degrees, 

 aifected by such conditions. Not for a long time after they had 

 passed away — after, that is, what we call the " close of the Glacial 

 Period", when the ice had disappeared from Northern and Central 

 Europe — can the countries along the southern shores of the 

 Mediterranean have settled down to climatic conditions approximately 

 like those that obtain in them to-day. 



Now, the monuments of the First Dynasty in Egypt carry us back 

 considerably more than 4000 years before the Christian era — that 

 is to say, more than 6000 years before the present time — and these 

 monuments are those of a thoroughly settled and civilized people. 

 But behind this time lies the period of the prehistoric culture, which, 

 in the opinion of the best authorities such as Professor Flinders Petrie, 



