A HISTORY OF SCIENCE 



we mean is that modern knowledge has penetrated the 

 mists of the past for the period we term historical with 

 something more of clearness and precision than it has 

 been able to bring to bear upon yet earlier periods. 

 New accessions of knowledge may thus shift from time 

 to time the bounds of the so-called historical period. 

 The clearest illustration of this is furnished by our in- 

 terpretation of Egyptian history. Until recently the 

 biblical records of the Hebrew captivity or service, 

 together with the similar account of Josephus, furnished 

 about all that was known of Egyptian history even of 

 so comparatively recent a time as that of Ramses II. 

 (fifteenth century B.C.), and from that period on there 

 was almost a complete gap until the story was taken 

 up by the Greek historians Herodotus and Diodorus. 

 It is true that the king-lists of the Alexandrian his- 

 torian, Manetho, were all along accessible in somewhat 

 garbled copies. But at best they seemed to supply 

 unintelligible lists of names and dates which no one 

 was disposed to take seriously. That they were, 

 broadly speaking, true historical records, and most 

 important historical records at that, was not recognized 

 by modern scholars until fresh light had been thrown 

 on the subject from altogether new sources. 



These new sources of knowledge of ancient history 

 demand a moment's consideration. They are all-im- 

 portant because they have been the means of extending 

 the historical period of Egyptian history (using the word 

 history in the way just explained) by three or four 

 thousand years. As just suggested, that historical 

 period carried the scholarship of the early nineteenth 

 century scarcely beyond the fifteenth century B.C., but 



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