Egyptian Chronology. 459 



year of the Egyptians was determined ; a principle that was only 

 true at a remote period, and has since ceased to be applicable. 



II. From the length assigned to the Sothic Cycle, at the end 

 of which the beginning of the civil and astronomic years returned 

 to the same day. A length which was given by the ancient 

 authors is correct only between certain epochs, and was not 

 true at those which were more remote, nor consistent at any 

 time with the true length of the tropical year. 



III. From the groupeof Zodaical stars assigned as the place 

 of the sun, at the beginning of the agricultural year of the 

 Egyptians, excluding all dates previous to his being in this 

 groupe at the time of the rising of the Nile. 



IV. From a version of a remarkable passage in Herodotus; 

 a version in which I had the aid of my learned colleague, Pro- 

 fessor Moore, and which I, at the time, believed had the 

 merit of ojiginality. You, however, inform me, that it has 

 been construed in a similar manner by St. Martin, and this 

 coincidence adds no small weight to the views 1 at that time 

 supposed I entertained unsupported. 



I. Before the introduction of calendars founded upon astro- 

 nomical tables, it was the universal custom of the nations of 

 antiquity to regulate their agricultural labours by the heliacal 

 rising of remarkable stars. In the Egyptian climate, the whole 

 of these were also determined by the phenomenon of the rising 

 of the Nile. The country, which, without this happy provision 

 of nature, would be absolutely desert, a mass of barren and in- 

 hospitable sand, and which suffers from famine when the inun- 

 dation does not reach its mean height, is annually restored to 

 cultivation by its means, and rendered one of the most fertile 

 regions of the earth. The moisture with which the inundation 

 charges the earth is long kept up by abundant dews, that the 

 alternating excesses of solar and terrestrial radiation, during the 

 day and night, give rise to ; but, at the approach of the summer 

 solstice, these naturally lessen, and, finally, cease altogether, 

 vegetation loses its support, and the fertile fields assume the 

 appearance of a sandy waste. Hence, the rising of the Nile is 

 watched for, with the most intense expectation, not merely on 

 the neighbouring shores of the river, but on the furthest fron- 

 tier of the country, whence the joyful tidings are transmitted 

 with all possible celerity. Hence, too, the astronomic pheno- 



