A HISTORY OF SCIENCE 



important influences to the Western world. "Our di- 

 vision of time is of Babylonian origin," says Hommel; 7 

 " to Babylonia we owe the week of seven days, with the 

 names of the planets for the days of the week, and the 

 division into hours and months." Hence the almost 

 personal interest which we of to-day must needs feel 

 in the efforts of the Babylonian star-gazer. 



It must not be supposed, however, that the Chal- 

 dean astronomer had made any very extraordinary 

 advances upon the knowledge of the Egyptian " watch- 

 ers of the night." After all, it required patient ob- 

 servation rather than any peculiar genius in the ob- 

 server to note in the course of time such broad as- 

 tronomical conditions as the regularity of the moon's 

 phases, and the relation of the lunar periods to the 

 longer periodical oscillations of the sun. Nor could 

 the curious wanderings of the planets escape the at- 

 tention of even a moderately keen observer. The 

 chief distinction between the Chaldean and Egyptian 

 astronomers appears to have consisted in the relative 

 importance they attached to various of the phenomena 

 which they both observed. The Egyptian, as we have 

 seen, centred his attention upon the sun. That lumi- 

 nary was the abode of one of his most important gods. 

 His worship was essentially solar. The Babylonian, 

 on the other hand, appears to have been peculiarly im- 

 pressed with the importance of the moon. He could 

 not, of course, overlook the attention-compelling fact 

 of the solar year; but his unit of time was the lunar 

 period of thirty days, and his year consisted of twelve 

 lunar periods, or 360 days. He was perfectly aware, 

 however, that this period did not coincide with the 



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