ITS EARLIEST STAGES. 135 



the only difference is, that the dark part of the moon is usually not 

 visible at all. 



This doctrine is ascribed to Anaximander. Aristotle was fully aware 

 of it. 62 It could not well escape the Chaldeans and Egyptians, if they 

 speculated at all about the causes of the appearances in the heavens. 



Sect. 11. — Eclipses. 



Eclipses of the sun and rnoon were from the earliest times regarded 

 with a pecidiar interest. The notions of superhuman influences and 

 relations, which, as we have seen, were associated with the luminaries 

 of the sky, made men look with alarm at any sudden and striking 

 change in those objects ; and as the constant and steady course of the 

 celestial revolutions was contemplated with a feeling of admiration 

 and awe, any marked interruption and deviation in this course, was 

 regarded with surprise and terror. This appears to be the case with 

 all nations at an early stage of their civilization. 



This impression would cause Eclipses to be noted and remembered ; 

 and accordingly we find that the records of Eclipses are the earliest 

 astronomical information which we possess. "When men had discov- 

 ered some of the laws of succession of other astronomical phenomena, 

 for instance, of the usual appearances of the moon and sun, it might 

 then occur to them that these unusual appearances also might proba- 

 bly be governed by some rule. 



The search after this rule was successful at an early period. The 

 Chaldeans were able to predict Eclipses of the Moon. This they did, 

 probably, by means of their Cycle of 223 months, or about 18 years; 

 for at the end of this time, the eclipses of the moon begin to return, at 

 the same intervals and in the same order as at the beginning. 55 Prob- 

 ably this was the first instance of the prediction of peculiar astronom- 

 ical phenomena. The Chinese have, indeed, a legend, in which it is 

 related that a solar eclipse happened in the reign of Tchongkang, 

 above 2000 years before Christ, and that the emperor was so much 

 irritated against two great officers of state, who had neglected to pre- 

 dict this eclipse, that he put them to death. But this cannot be 

 accepted as a real event : for, during the next ten centuries, we find no 

 single observation or fact connected with astronomy in the Chinese 



« Probl. Cap. xv. Art. 7. 



"The eclipses of the sun are more difficult to calculate ; since they depend upon 

 the place of the spectator on the earth. 



