A Research On XUE Fengzuo’s Works On Calendrical Astronomy

In the late Ming Dynasty,European astronomy was introduced into China,and it became the official astronomical theory later in the Qing Dynasty.Indubitably,the following development of Chinese astronomy was profoundly impacted by European astronomy.Meanwhile,Chinese astronomers in this period made different responses to European astronomy.Due to its significance in the history of astronomy and the history of the communication between China and West,the response of Chinese astronomers is an important subject all the time.Although many valuable works have been done in this area,the study on XUE Fengzuo 薛凤祚,one of the most important astronomers in the early Qing Dynasty,is apparently not enough.Especially his works on calendrical astronomy have not yet been systematically researched.Based on the previous scholarship,and by synthetically analyzing a variety of historical materials including newly discovered literature and using computer simulation to identically duplicate the calculating procedures in relevant astronomical books,this dissertation gives a systematical study in the historical context on XUE Fengzuo and his works on calendrical astronomy.In general,some new progresses on a number of related topics were achieved in this dissertation,among which the most important ones can be summarized as follows.Firstly,we reexplored the life and works of XUE Fengzuo in this paper.According to the newly discovered historical materials,we made some complements and corrections about the description of XUE Fengzuo’s life.Focus has been laid on some affairs not mentioned before,including his intercourse and Confucian thought.When studying on XUE Fengzuo’s social contacts,we investigated the situations of his disciples in particular.Besides,after reconsidering the relation between XUE Fengzuo and the Neo-Confucian School of Mind 心学,our conclusion turns out to be totally different from former scholars.In fact,XUE Fengzuo had never broken away from the Neo-Confucian School of Mind.Moreover,we also found that the exact publication time when XUE Fengzuo’s most important works(such as Lixue Huitong历学会通,Qihua Qianliu 气化迁流,Lianghe Qinghui 两河清汇,etc)still could not be confirmed,and most former scholars’ views on this issue were incredible by a lack of historical evidence.Secondly,we made a systematical study on the calendrical astronomy in XUE Fengzuo’s works.Because the astronomical part of Tianbu Zhenyuan天步眞原 is actually an adaptation of Tabulae Motvvm Colestium Perpetuae by the Belgian astronomer Philippe van Lansberge,we studied the astronomical system in Tabulae firstly.As a follower of Copernicus,Lansberge constructed a heliocentric system in Tabulae,so we also compared the astronomical theories in Tabulae and De Revolutionibus Orbium Coelestium.In fact,for the description of the motions of the sun,moon and five major planets,there is little difference between the models in Tabulae and De Revolutionibus;only the lunar models in the two books are different obviously.However,Lansberge adjusted most of the parameters in these models.He also made some experiential corrections in the calculations,such as the adjustment on the equation of precession and the correction to the motion of Mars.Based on the computer simulation of the positional calculations of the sun,moon and five major planets,we found that the astronomical theories in Tabulae are more accurate than the ones in De Revolutionibus.Meanwhile,we analysed the accuracies of the astronomical theories in Tianbu Zhenyuan and XiyangXinfa Lishu西洋新法历书.As it turned out,the two systems each have advantages,and their accuracies are neck and neck.Thirdly,we examined the textual improprieties in Tianbu Zhenyuan.Compared with Tabulae Motvvm Colestium Perpetuae,we could confirm that there are many mistakes,e.g.errors of the numerical values and illustrations,and some misnomers in Tianbu Zhenyuan.As a result,it makes the book very obscure and abstruse and hard to understand.Furthermore,there is a fundamental question in Tianbu Zhenyuan.The method how to compute the time difference between a given time and the epoch was not described exactly.Indeed,XUE Fengzuo had realized the existence of these textual improprieties,and consequently he made a lot of amendments when he compiled the Main Portion(Zhengji 正集)of Lixue Huitong.However,most of the contents which XUE Fengzuo had corrected are in the calendrical part of the Main Portion,and there are still many textual improprieties in the theoretical part.Overall,it is true that all kinds of textual improprieties could be found in XUE Fengzuo’s works on calendrical astronomy,and this situation inevitably hinder readers to understand and use these books.Finally,we made a systematic textual research on the origins of the contents in Lixue Huitong.Based on these results,an analysis of the features on XUE Fengzuo’s integration of calendrical astronomy was given.Acutually,the contents concerning calendrical astronomy in Lixue Hitong are mainly adapted from Tianbu Zhenyuan,Gujin Luli Kao古今律历考,Xiyng Xinfa Lishu and Huihui Lifa回回历法,and the origins of other contents are various.Additionally,we also found that there are two distinct features on XUE Fengzuo’s integration of different systems of calendrical astronomy.Firstly,he composed his own system,namely,the "New Chinese Method"新中法,followed the format of Chinese traditional calendar;Secondly,he emphasized the astrological applications of calendrical astronomy particularly.As a matter of fact,there is an intimate connection between XUE Fengzuo’s integration and the historical context,and his extraordinary way of integration is a response to the dissemination of European astronomy and astrology in late Ming and early Qing China.Furthermore,in the concluding remarks of this dissertation,we also discussed some other issues,such as the features and influence of XUE Fengzuo’s works on calendrical astronomy,the similarity and difference between XUE Fengzuo and other contemporary Chinese astronomers.Based on these discussions,a historical evaluation of XUE Fengzuo’s works on calendrical astronomy was given at last.