ASTRONOIMICAL SCIENCE IN THE ANCIENT ORIENT 207 



calendar lias been always practised in the Orient until recently. 



To fix the date of the compilation of the Tso-chvan 'J^^ is a 

 very interesting problem. Fortunately, we find in the Tso-chvan -j^% 

 and also in the Kuo yii ^|f which is without doubt intimately 

 associated with the former, many astrological narratives, giving therein 

 the positions of Jupiter in the heaven. By comparing these positions 

 with the results of modern calculations (e.g., with Neugebauer's Ta/el 

 der Planeten), and studying the increase of deviation toward the 

 earlier age, we may easily infer that all these positions of Jupiter are 

 nothing but products of an erroneous calculation at an epoch about 

 370-360 B.C., made with an assumed period of 12 years instead of 

 11.86 years for the period of revolution. 



It is, then, evident that the epoch of the compilation of the 

 Tso-cJiuan can not be earlier than circa 360 B.C. ; further study of 

 the text-content shows that it can not be much later than that epoch. 

 If the epoch of the compilation of the Tso-cliuon be thus once fixed 

 to about 360 B.C., then we have in our hands voluminous material 

 originating from a definite period, and hence immensely valuable for 

 the investigation of ancient Chinese civilization. We see, that the 

 Chan-lcvo age, 480-250 B.C., although it has been usually looked upon 

 as a kind of dark age, must have been in reality a period of progress, 

 perhaps as a result of free competition in a wider circle. In the 

 scope of astronomy, we see that remakable progress at least along the 

 following lines was made during this period : 



( i ) Foundation of the calendar system Ghuan yii U ^3^Mj 

 (ii) Observation of all of the five naked-eye planets, giving rise to 

 (iii) The foundation of the Wu hang theory 5£^tl^^ according to 

 which all the phenomena in our universe in general may be 

 looked upon as the various combinations of five essential 

 elements, wood, fire, earth, metal, and water. The school hold- 

 ing the Wu hang theory predominated among the learned classes 

 in the Orient for as long as over 2000 years after this time, 

 (iv) Systematic observation of the starry heavens. 



6. Foundation of the Calendar System. 



We have seen that in the latter half of the Cli'un-ch'iu period 

 (722-481 B.C), the determination of the seasonal epochs had been 

 greatly improved, and hence the harmonizing of the lunar and solar 



