Studies in the History of Natural Sciences 　NO.4 2001

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A Core Algorithm of Methods for Calculating Solar Shadow and Water Clock in Ancient China’s Calendar-making System……QU Anjing,WANG Hui,YUAN Min

【Abstract】 The history of ancient Chinese algorithms for calculating solar shadow and water clock have been widely explored,meanwhile,th e precision of these algorithms has been anatomized by some scholars.But up to pr e sent,little attention has been paid to the intrinsic essentiality of xiaoxitonglü that was proposed by the Buddhist monk Yi Xing of the Tang Dynasty w hile he calculated calendar items about solar shadow and water clock in Dayan Li (the Da yan Calendar). Xiaoxitonglü was also known as xiaoxishu or xiaoxidingshu in later calendars.It was a core algorithm,or in other words a fundamental element ,of methods for calculating solar shadow and water clock in ancient Chinese cale ndar making system.Many calendar items would find their value coming from this element operating with relevant constants.This element had been adopted in p rogrammes of many calendars during the Tang and Song Dynasties. Let t be the hour angle, δ be the declination,and φ be the altitude .There is a spherical trigonometry relation between them: Suppose t be a linear interpolation function of δ as it was always don e by ancient Chinese calendar makers: s=360°，η is a constant Based on the parameters′ values on the very point w hen the sun turned up on the horizon on the winter solstice during Kaiyan period in the Tang Dynasty,there is Let ψ 0=-0 25+ts， or ψ =0 05 -｜ψ 0 ｜，as t he fountainhead of xiaoxidingshu, it reveals the core algorithm's signification in Mathema tical Astronomy.

The Accuracy of Dayan Li's Calculations on Solar and Lunar Eclipses……HU Tiezhu

【Abstract】 A solar eclipse was considered a verｙ important phenomenon in ancient China because people believed it to be heaven's warning to the emperor for his mistakes.A lunar eclipse was also of similar importance.Therefore, ancient Chinese astronomers paid a lot of attention to the calculation of solar and lumar eclipses. Four out of seven ancient Chinese calendars are related to eclipses.This article develops computer programs based on the methods of Daya n Li (the Dayan Calendar)──one of the most famous calendars in 8th century China,and calculates the solar and lunar eclipses in its time.It concludes: Dayan Li could predict all the solar and lunar eclipses that occurred in Xi'an. C ompared to modern calculations,the average difference of time between Dayan Li's predictions and modern calculations is smaller than 1 hour,and the average difference of magnitude is smaller than 0 3.But from the perspective of astron omers in the 8th century，only about 50% solar eclipses and 70% lunar eclipses predicted by Dayan Li could be seen in Xi'an.Hence,ancient astronomers had to improve their method to increase accuracy,which accounts for the frequent change of calendars after the Dayan Li .And in the next several hundred years the Chinese astronomers made a big progress in the accuracy of calculations for eclipses. 

The Mathematical and Physical Structure of Moon's Age Calendar and the Method for Its Arrangement……LI Yong

【Abstract】 By use of the statistics method of mathematics and physics, astronomical calculations and the method of calendric arrangement, this pa per provides digital tables, known as the mathematical and physical structure of Moon's age calendar, as one of the useful times research instruments for words and expressions having certain Moon's age characteristics. They can be used:(1)T o derive the possible year interval directly by their difference from the Gan zhi(the heavenly stems and earthly branches, the ancient Chinese date recording method being of the 60 day cycle, in which the repetitive cycle is independent of any astronomical parameter, and each day has its own name and can also be expressed by the numbers from 1 to 60)numbers;(2)To arrange calendars of the M oon's age,such as the calendar of the Jinwen(the Moon's age calendar arranged by ancient words which were mainly carved on bronze);(3)To analyse the errors of the Moon's age regions and year intervals of the Moon's age calendar, for example, the calendar of the Jinwen obtained by the Xia Shang Zhou Chronological Project. 

The Bower Manuscript and Siddhasra: Two Sanskrit Medical Classics in the Ancient Western Regions……CHEN Ming

【Abstract】 Both Siddhasra and The Bower Manuscript are classical Indian medical texts that had been disseminated to Central Asia a nd Xinjiang.After comparing Siddhsra with The Bower Manuscript ,a famo us early work from Kucha in Xinjiang in 1889,the author finds that both texts ar e selections of prescriptions for clinical practice and propagation.The two text s were used among some non Chinese cultural circles in Central Asia and Xinjian g,such as the Sanskrit,Khotanese and Gandhrī cultural circles.Together with Indian medical texts, Siddhasra greatly enrich es the ancient medical culture in Xinjiang and gives the latter a rather obvious A -yurvedical flavour.Those same prescriptions in Siddh a sra and The Bower Manuscript show that Indian medicine occupies an important position in the history of Xinjiang s medical culture.In addition,the author also notices the great difference between both:the former is not Buddhist,but the latter is. 

The Theoretical and Practical Significance of Plant Distant Grafting in Ancient and Modern China……LIU Yongsheng

【Abstract】 This paper emphatically discusses the theoretical and practical significance of plant distant grafting on the basis of introducing th e records of plant distant grafting in ancient and modern China.Plant distant gr afting has been widely used in enhancing ornamental value,improving fruit qualit y,raising yield,building up resistance and adaptive faculty,and developing dista nt graft hybrid.It can also be used as a means to study plant genetics,plant phy siology and plant pathology. 

A Conjectural Construction of the Giant Chinese Gnomon in Dadu of the Yuan Dynasty……Li Di

【Abstract】 The paper re studies the gaobiao (gian t Chinese gnomon)designed by the astronomer Guo Shoujing (1231 1316)at the beginning of th e Yuan Dynasty.Based on a his discussion of what a possible method might be used by Guo to cast and install the giant Chinese gnomon,providing that the gnomon h ad been indeed made by Guo Shoujing,the author argues that Guo Shoujing had only designed but not cast the gnomon.He thinks that the so called Giant Gnomon use d in Dadu(today's Beijing)should be the same as that at the old Observatory in Dengfeng,Henan,that is,a cross bar (heng liang) installed on the top railing o f th e Guiying Tang(Gnomon Shadow Hall)was instead of the Giant Gnomon.The Hall,Gnomon and Gnomon Shadow Template( gui )were arranged in a line from south to north direction. 更多

Derek J.de Solla Price and His Science Since Babylon……REN Yuanbiao

【Abstract】 Derek J.de Solla Price and his book Science Since Babylon have produced much influence on Scientometrics and other disciplines.This doesn't negate the fact that Derek Price was an outstanding historian of science and Science Since Babylon is a classical work of history of science . Science Since Babylon originated Price's intention “toattact the attention of humanists and scientists by oral presentation to what is usually called the History of Science”and it has carried the intention out very well by emerging a set of significant achievements of its author in the history of science.These significant achievements not only had inspired people to understand science and the discipline of history of science then but also are still giving us some inspiration today.

On Mistakes of Knowledge about the History of Science and Technology in Bai Shouyi's General History of China……GUAN Zengjian

【Abstract】 The work General History of China with Prof.Bai S houyi as its chief editor is a monument in the sphere of studies on the history of China.It pays great attention to the knowledge of science and technology,whi ch makes it different from traditional works on the history of China.However,the re are some mistakes in the part mentioned above.This paper points out the mista kes and then has them analysed.The author thinks the book still deserves to be h ighly esteemed in academic circles despite its slight blemishes.