EGYPTIAN SCIENCE 



means so much so in actual practice. We need go no 

 farther than to our own experience to know that the 

 names of seasons, as of months and days, come to have 

 in the minds of most of us a purely conventional sig- 

 nificance. Few of us stop to give a thought to the 

 meaning of the words January, February, etc., except 

 as they connote certain climatic conditions. If, then, 

 our own calendar were so defective that in the course 

 of 120 years the month of February had shifted back 

 to occupy the position of the original January, the 

 change would have been so gradual, covering the 

 period of two life-times or of four or five average gen- 

 erations, that it might well escape general observation. 

 Each succeeding generation of Egyptians, then, may 

 not improbably have associated the names of the sea- 

 sons with the contemporary climatic conditions, 

 troubling themselves little with the thought that in an 

 earlier age the climatic conditions for each period of 

 the calendar were quite different. We cannot well 

 suppose, however, that the astronomer priests were 

 oblivious to the true state of things. Upon them de- 

 volved the duty of predicting the time of the Nile 

 flood; a duty they were enabled to perform without 

 difficulty through observation of the rising of the sol- 

 stitial sun and its Sothic messenger. To these ob- 

 servers it must finally have been apparent that the 

 shifting of the seasons was at the rate of one day in 

 four years; this known, it required no great mathe- 

 matical skill to compute that this shifting would finally 

 effect a complete circuit of the calendar, so that after 

 (4 x 365 =) 1460 years the first day of the calendar year 

 would again coincide with the heliacal rising of So this 



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