é’n@–Î

**
Introduction of Seki Takakazu (Kowa)**

Shigeru JOCHI

INTRODUCTION@OF SEKI TAKAKAZU (1) The influence of Chinese mathematics on Wasan (Japanese mathematics) The influence of Chinese mathematics was felt in most East Asian countries. In the case of Japan, it was introduced into the country two times. The first time was in the eighth century, when many mathematical arts were introduced and taught in the University, but Japanese mathematicians only imitated the work of Chinese authorities, and its level was limited. The second time was at the end of the sixteenth century|at which point, Japanese mathematicians applied Chinese mathematics, and were to produce brilliant achievements. It is difficult to make a comparative study of the mathematics of two completely different civilizations, because they do not have the same intellectual background. But Chinese mathematics and Japanese mathematics used the same language, rather than just the same Chinese characters, thus mathematicians could understand mathematical notions easily. That is to say, if Japanese mathematicians had Chinese mathematical books, they could have had the same background as Chinese mathematicians. I wonder whether it is possible to make a comparative study of them using historical method. Instead, through studying Japanese mathematics in the 17th century, we may be able to understand strong and weak points of Chinese mathematics in the 13th century. I would like to consider the case of Seki Takakazu èF˜a (1642?-1708), the best mathematician in Japan. He very probably studied Chinese mathematics, but it is difficult to demonstrate precisely how he studied Chinese mathematics from his biography. Because his son-in-law gambled away his post, nobody could hand down Seki Takakazu's biography. Thus we cannot know exactly the nature of his education. Therefore, I will have to try, in this thesis, to consider his education in light of the similarity between his works and Chinese mathematics. (2) Biographical study of Seki Takakazu Because nobody could hand down Seki Takakazu's biography, we cannot even fix his birth year exactly. He became revered as a "Sansei" ŽZ¹ (mathematical sage), and the scientific studies of his biograpy was neglected. However, since Mikami Yoshio's ŽOã‹`•v (1875-1950) study (*1) , there are some good studies (*2), and his biographical table(*3) is as follows Seki Takakazu's biography 1637? - 1642? Born in Edo ? (now Tokyo) or Fujioka ? (now Fujioka-shi, Gumma prefecture ŒQ”nãp“¡‰ªŽs). The Second Son of Uchiyama Nagaakira “àŽR‰i–¾ (?-1662?), and of the daughter (?-1682, name unknown) of Yuasa Yoemon “’ŸÇäo‰E‰q–å. His other names are Sinsuke V•, Shihyo Žq•^ and Jiyute Ž©—R’à. year unknown Became a son-in-law of Seki Gorozaemon èŒÜ˜Y¶‰q–å(?-1665). 1661 Transcribed the Yang Hui Suan Fa —k‹PŽZ–@ (Yang Hui's Method of Computation) at Nara “Þ—Ç. Became a member of Load Kofu (after became 6th Shogun of Ienobu “¿ì‰Æé).? 1663 Wrote the Kiku Yomei Sampo ‹K‹é—v–¾ŽZ–@ (Essential Mathematical Methods of Measures) 1665 Seki Gorozaemon was died. 1672? Wrote the Ketsugi-Sho To-jutsu è‹^´“šp (Answers and Methods of the Sampo Ketsugi-Sho). 1674 wrote the Huttan Kai To-jutsu –ÜœÝ‰ü“šp (Answers and Methods of the Sampo Huttan Kai). In Dec., published the Hatsubi Sampo á¢”÷ŽZ–@ (Mathematical Methods for Finding Details). 1680 In Mar. wrote the Juji Hatsumei ŽöŽžá¢–¾ (Comments of the Works and Days Calendar). In July, wrote the Happo Ryakketsu ”ª–@—ªŒ (Short Explanations of Eight Items). 1681 In Apr., wrote the Jujireki-kyo Rissei no Ho ŽöŽž—ïãS—§¬”V–@ (Methods of Manual Tables of the Works and Days Calendar). 1683 In June, wrote the Shoyaku no Ho ”–ñ”V–@ (Methods of Reduction), Sandatsu Kempu no Ho ŽZ’Eé„•„”V–@ (Methods of Solving Josephus Question) , Hojin Ensan no Ho •ûwš¢·”V–@ (Methods of Magic Squares and Magic Circles). In Aug., wrote the Kaku Ho Šp–@•À‰‰’iš¤ (Methods of Angles and Figures of Japanese Algebra). On 9th Sep., wrote the Kai Hukudai no Ho ‰ð•š‘è”V–@ (Methods of Solving Secret Questions). 1685 In Aug., wrote the Kai Indai no Ho ‰ðèª‘è”V–@ (Methods of Solving Concealed Questions). Wrote the Byodai Meichi no Ho •a‘è–¾’v”V–@(Methods of Correcting Failures as Questions). In Nov., wrote the Kaiho Hompen no Ho ŠJ•û–|Ì”V–@ (Overturn Methods of Solving Higher Degree Equations). In Dec., wrote the Daijutsu Bengi no Ho ‘èp™ž‹c”V–@(Methods of Discriminant). Wrote the Kai Kendai no Ho ‰ðŒ©‘è”V–@ (Methods of Solving Findable Questions), Ky#seki ‹Ï (Computations of Area and Volume), Ky#ketstu Henk$ So Ÿ{èÌŒ`‘ (Manuscript of Transformation of Spheres) and Kaiho Sanshiki ŠJ•ûŽZŽ® (Formulae of Solving Higher Degree Equations). 1686 In Jan., wrote the Seki Teisho è’ù‘ (Seki Kowa's Amendments). 1695 Became Makanai-gashira ˜d“ªichief treasurer, 200-pyo •U and 10-nin buchi •}Ž (ten retainers' salary) 1697 In May, wrote the Shiyo Sampo ŽléPŽZ–@ (Mathematical Methods of Computing Four Points on the Lunar Orbit). 1699 In Jan., wrote Temmon Sugaku Zatcho “V•¶É›{è¶’˜ (Notes of Astronomy and Mathematics). Became Kanji-gata Yoyaku Š¨’è•û—p–ðiauditor, 300-pyojH 1701? Was Kanji-gata Yoyakui300-pyoj @@@Uchiyama Nagayoshi (Seki's 3rd brother) “àŽR‰iÍ became Kanjo Š¨’èiAccouter, 100-pyojof Load Kofu. 1702 Was Kanji-gata Yoyakui300-pyoj 1704 In Nov., gave a "Sampo Kyojo" ŽZ–@‹–ó (Licence of Mathematics) to Miyaji Shingoro ‹{’nVŒÜ˜Y.? In Dec., when Tokugawa Ienobu became Shogun, Seki Kowa became a Nando Kumigashira ”[ŒË‘g“ª (chief treasurer, 250 Pyo and 10nin-buchi, then 300 Pyo. 1706 In Nov., retired, and became a member of Kobushin-gumi ¬•¿‘g (lit. small builders group). 1708 On 24th Oct., died from a disease. 1710 The Taisei Sampo ‘å¬ŽZ–@ (Complete Works of Seki Kowa) was edited. 1712 The Katsuyo Sampo Š‡—vŽZ–@ (Essential Mathematics) was published. 1714 On 30th Mar., the Shukuyo Sampo h—jŽZ–@ (Mathematical Methods of Constellations). 1724 Seki Kowa's son-in-law, Hisayuki ‹v”V (1690-?) (or Shinshichiro VŽµ˜Y) became Kofu Kimban b•{‹Î”Ô (member of Kofu city office). 1737 Seki Hisayuki lost his position owing to his gambling activities. As above, Seki Kowa's works are quite huge, however, there are few evidences about his education and his personal infomation. Even his exact name is notknown to foreign scholars. Now, let us consider this problem. In Eastern Asian countries, an adult had some names, which were called "Zi" (or "Azana" in Japanese) Žš (alias) or "Hao" (or "Go" in Japanese) åj (penname) and so on. Their real name was used only in the family, "Zi" (alias) was used officialy, thus the real name was not known to unrelated person. In the case of Seki Kowa, his alias ("Azana") was Shinsuke V•, and his styles or pen-names ("Go") was Shihyo Žq•^ and Jiyute Ž©—R’à, and real name was Takakazu F˜a. He used his real name when he published books, it was a custom of Japanese mathematicians in that age. Thus readers did not know how "F˜a" was read. It does not mean that the education of readers was inferior. It was a characteristic of Japanese names. Ancient Japan had no written characters of its own; Chinese characters were introduced in the Nara “Þ—Ç period, and not before. Chinese characters have no element of pronunciation, i.e., they are not phonetic signs. Therefore Japanese could read one Chinese character in several ways of pronunciation. For example; the character of É (numbers) is read "Shu" by Chinese. Japanese imitated this sound, but the system of Japanese utterance was not the same as that of the Chinese, thus Japanese spoke with an accent to read this character to "Su". It is called "On" ‰¹ (Chinese pronunciation) reading. And this character means "number", In Japanese it is read "Kazu", which means "number". This is the translation, it is called "Kun" ŒP (Japanese pronunciation) reading. Moreover Chinese culture was introduced for many years and from many localities in China, sometimes the pronunciations were different. Thus there are three "On" readings in Japan, basically. Kan-on Š¿‰¹ (Han dynasty's)\\1) On ‰¹ (Chinese pronunciation) Go-on Œà‰¹ (Wu dynasty's) \\2) b So-on ‘v‰¹ (Song dynasty's) \3) Kun ŒP (Japanese pronunciation) \\\\\\\\\\\\\\\\\4) Usually, Confucian terms are "Kan-on" reading and Buddhist's terms are "Go- on" or "So-on" reading. The two characters "F" and "˜a" can be read in the followings ways: 1) Ko 1) Ka "F" 2) Kyo "˜a" 2) Wa 3) - 3) - 4) Takashi (adv.) 4) Kazofu (v.) (Tsukaeru (v.)) (Yawaragu (v.)) (Nagomu (v.)) Therefore it is possible to read "F˜a" in nine ways. There are some rules to read a set phrase, which is consisted of two Chinese characters. If "On" reading is used for the first character, the same would apply in reading the second character; if "Kun" reading is used for the first character, it is also used in reading the second character. Usually "On" and "Kun" readings are not used together, but there is no absolute rule. Japanese personal names are often too difficult to read. In Japan, when there is uncertainty concerning how a name is read it is customary to use the "On" reading to avoid serious mistake. Seki Kowa became too famous, most Japanese mathematicians knew him only through his mathematical arts. Thus Seki Takakazu became known as Seki Kowa. For Japanese mathematicians I give the original pronunciation of the real name if possible, but sometimes I cannot read the name. Thus all nemes of Oriental persons are given in Chinese characters, together with birth year and death year in the text. (3) Similarity between Chinese mathematics and Japanese mathematics As we considered in section 2, Seki Kowa's works are in many fields. According to Hirayama Akira's •½ŽR’ú (fl.1959) studies(*4), these are classified under 15 categories, as follows: Seki Takakazu's works 1) "Bosho-ho" –T‘–@ and "Endan-jutsu" ‰‰’ip, Japanese algebra 2) solution of higher degree equation 3) properties (e.g., number of solutions) of higher degree equation 4) infinite series 5) "Reyaku-jutsu" —ë–ñp, approximate value of fractions 6) "Senkan-jutsu" ãÆŠÇp, indeterminate equations 7) "Shosa-ho" µ·–@, the method of interpolation 8) Obtained Bernoulli numbers by "Ruisai Shosa-ho" —ÝÙµ·–@ 9) computing area of polygons 10) "Enri" š¢—, principle of the circle 11) Newton's formula by "Kyusho" ‹‡¤ method 12) computing area of rings 13) conic curves line 14) "Hojin" •ûw, magic squares, and "Enjin" š¢w, magic circle 15) "Mamakodate" ã‹Žq—§, Josephus question "Metuke-ji" –Ú•tŽš, game of finding a Chinese character Table 1 Hirayama's classification of Seki Kowa's works Each of Seki Kowa's works was a great one, but most of the subjects he took up were not his original ideas, being typical works of Chinese mathematics in the Song ‘v and Yuan Œ³ dynasties. These are, according to Li Yan's —›™V (1892-1963) studies(*5), as follows: a) "Cheng-Chu Ke-Jue" ˜©œ‰ÌŒ (verses for multiplication and division) Yang Hui Suan Fa —k‹PŽZ–@ (Yang Hui's Method of Computation) Suan Fa Tong Zong ŽZ–@“@ (Systematic Treatise on Arithmetic) b) "Cong-Huang-Tu Shuo" c‰¡š¤à (magic squares) Yang Hui Suan Fa (Yang Hui's Method of Computation) Suan Fa Tong Zong (Systematic Treatise on Arithmetic) c) "Shu Run" É˜_ (numbers theorems) Shu Shu Jiu Zhang É‘‹ãÍ (Mathematical Treatise in Nine Sections) d) "Ji-Shu Run" ‹‰É˜_ (series) Meng Xi Bi Duan –²Ÿâ•M’k (Dream Pool Essays) Yang Hui Suan Fa (Yang Hui's Method of Computation) Si Yuan Yu Jian ŽlŒ³‹ÊŠÓ (Precious Mirror of the Four Elements) e) "Fang-Cheng Run" •û’ö˜_ (higher degree equations) Ce Yuan Hai Jing ‘ªš¢ŠC‹¾ (Sea Mirror of Circle Measurements) Shu Shu Jiu Zhang (Mathematical Treatise in Nine Sections) Suan Xue Qi Meng ŽZ›{Œ[–Ö (Introduction to Mathematical Studies) f) "He Yuan Shu" Š„š¢p (the method of dividing the circle) Shou Shi Li ŽöŽž—ï (Works and Days Calendar) Table 2 Classification of Chinese mathematics works and important books in the Song and Yuan dynasties Considering to which categories each Seki Kowa's work belongs in table 2, we see that only 1) and 14) are Seki Kowa's original subjects, the others belong to inherited Chinese subjects in the Song and Yuan dynasties, as illustrated in table 3. {\\\\\\\\\\\{\\\\\\\{ b categories b Seki's work b {\\\\\\\\\\\{\\\\\\\{ b a) verse b- b {\\\\\\\\\\\{\\\\\\\{ b b) magic squares b14) b {\\\\\\\\\\\{\\\\\\\{ b c) indeterminate eqs.b5)6)15) b {\\\\\\\\\\\{\\\\\\\{ b d) series b4)7)8)11) b {\\\\\\\\\\\{\\\\\\\{ b e) higher degree eqs.b2)3) b {\\\\\\\\\\\{\\\\\\\{ b f) circles b9)10)12) b {\\\\\\\\\\\{\\\\\\\{ Table 3 Similarity between Chinese Mathematics and Seki Kowa's Works In table 3, category f) describes one of the most popular subjects in Eastern mathematics. Since the Jiu Zhang Suan Shu ‹ãÍŽZp (Nine Chapters on the Mathematical Arts), most mathematical books described this subject. Thus it is not worth our while considering this origin. While category a) is one of the most important subjects for primary pupils of mathematics, it is not necessary to consider it in this thesis. Therefore we will consider categories b) to e) in the next section. (4) Opinions of how Chinese mathematics influenced on Seki Kowa As we considered above, there is no doubt that Seki Kowa was influenced by Chinese mathematics. Of course, he, as the other Japanese mathematicians, studied two popular texts, the Suan Fa Tong Zong and the Suan Xue Qi Meng. But the main works of the former fall into categories a) and b) of table 2, and the latter falls entirely into category e). Moreover, these are only introductions to these subjects. Thus it is not only these two books that influenced Seki Kowa. We must consider the more important books. But his biography is unreliable so much so that, we cannot know even his birth year. We have some indirect evidence about which Chinese mathematical arts influenced Seki Kowa. We will consider this first. (a) Opinions that Seki Kowa studied Chinese mathematics According to chapter 5 of the Burin Inkenroku •—ÑèªŒ©˜^ (Anecdotes of Mathematicians) by Sai To Ya Jin âV“Œ–ìl (18c), written in 1738, Seki Kowa discovered a difficult mathematics book in Nara “Þ—Ç, and studied it. There was a Chinese book with Buddhistic books in Nanto “ì“s (lit. northern capital, Nara “Þ—Ç), but nobody had been able to understand it. That book was not a Buddhistic book, a Confucian book nor a medical book. It was not known what kind of book it was, so it was only mended and given a summer airing. Shinsuke V• (Seki Kowa) knew it, and he guessed that it might be a mathematical book. He took vacations and went to Nanto to borrow it. He stayed there and sat up all night to copy it. Then he brought this hand-copied book back to Edo ]ŒË (Tokyo “Œ‹ž). He studied it day and night for three years, at last he mastered the secrets. He became the best mathematician in Japan (*6) . And Aida Yasuaki ˜ð“cˆÀ–¾ (1747-1817) criticized the alleged fact that Seki Kowa had burned this text-book in the Toyoshima Sankyo Hyorin æ²“‡ŽZãS•]—Ñ (Toyoshima's Comments about Mathematical Manual), written in 1804: Toyoshima Masami æ²“‡³”ü (?-?) said, "Seki Kowa was a good mathematician but his manner of study was poor. He burned his mathematical text book which he found." It seems probably that he burned the book because he had plagiarized Chinese mathematical methods and then wrote about them as if they were his own work. (*7) It had been known that Seki Kowa referred to Chinese mathematical texts since that time. Very probably he had studied some Chinese mathematical books that were not popularly known, and obtained certain ideas for his own works. Many scholars concluded what Seki Kowa's text book was. Here I introduce the former opinions and would like to comment on them. (b) Opinion concerning the Suan Xue Qi Mengg (Introductionn to Mathematical Studies) In a memorandum which is kept in Mito Shokokan …ŒË²lŠÙ (Mito private school), Honda Toshiaki –{‘½—˜–¾ (1744-1821) concluded that the book Seki Kowa copied was the Suan Xue Qi Meng. Seki Kowa was self-educated. First, he studied three mathematicians' books, Imamura Chisho ¡‘º’m¤ (?-?), Yoshida Mitsuyoshi ‹g“cŒõ—R (1598-1672) and Takahara Yoshitane ‚Œ´‹gŽí (?-?), and he mastered these mathematicians' strong points. He became the best mathematician. Then he borrowed Suan Xue Qi Meng (Introduction to Mathematical Studies) at Kofuku-ji ‹»•ŸŽ› (Kofuku temple) in Nanto, hand-copied it and mastered "Tengen-jutsu" “VŒ³p ("Tian Yuan Shu" in Chinese, technique of the celestial element). Then he continued to study mathematics, and completed the great works.(*8) The Suan Xue Qi Meng is the introduction to "Tian Yuan Shu" (Technique of the Celestial Element); this view is directed at Seki Kowa's work in higher degree equations. However, the Suan Xue Qi Meng was already republished in 1658 in Japan.|Hisada Gentetsu ‹v“cŒº“N (?-?) translated it to Japanese(*9). So, of course, Seki Kowa studied the Suan Xue Qi Meng, but it would not have been necessary to go to Nara to find this text book. Mikami Yoshio ŽOã‹`•v (1875-1950) suggested that it was Hisada Gentetsu that found the Suan Xue Qi Meng at Tofuku-ji “Œ•ŸŽ› (Tofuku temple) in Raku —Œ (Kyoto ‹ž“s) (10), not at Kofuku-ji (Kofuku temple) in Nara. Moreover the works of higher degree equations had been realized by Sawaguchi Kazuyuki àVŒûˆê”V (17c)(11). Therefore, we cannot accept this evidence. (c) Opinion concerning the Ce Yuan Hai Jing (Sea Mirror of Circle Measurement) Kano Ryokichi Žë–ì‹œ‹g (1865-1942) also pointed to the work of higher degree equation, but he concluded the textbook in question was the Ce Yuan Hai Jing (12) , which is the speciality book about "Tian Yuan Shu" (Technique of the Celestial Element). It, however, was introduced into Japan for the first time in 1726 (13), so Seki Kowa could not have read it. The fact that it had not been introduced before 1726 is supported by the evidence as follows: the letter which Mukai Motonari ŒüˆäŒ³¬ (?-?) sent to Hosoi Kotaku ×ˆäœAàV (?-?), published in the Sokuryo Higen ‘ª—Ê”éŒ¾ (Secret Comments of Surveying) by Hosoi Kotaku, states The chapter of Choken-jutsu ’¬Œ©p (Surveying); Some methods were described in the Ce Yuan Hai Jing Len Rei Shi Shu ‘ªš¢ŠC‹¾•ª —Þç×p (Classified Methods of the Ce Yuan Hai Jing )(14), Li Suan Quan Shu —ïŽZ‘S‘ (Complete Works on Calendar and Mathematics), Gou Gu Yin Meng ‹åŒÒˆø–Ö (Introduction to Sides of Triangle) and Shu Du Yan É“xŸ¥ (Generalisation on Numbers) which are thereby introduced into Japan (15). This evidence is very reliable because the Li Suan Quan Shu was introduced into Japan this same year(16). Therefore, we can conclude that the Ce Yuan Hai Jing was first known to Japanese mathematicians in 1726. Therefore we cannot accept Kano Ryokichi's opinion. (d) Opinion concerning the Zhui Shu ’Ôp (Bound Methods) Uchida Itsumi “à“cŒÜæV (1805-1882) told Okamoto Noriyoshi ‰ª–{‘¥˜^ (1847- 1931) that Seki Kowa's text book was Zhui Shu(17), which is Zu Chongzhi's ‘c‰« ”V (429-500) work, however, this work was lost in the Northern Song –k‘v dynasty. If the Zhui Shu was extant in Seki Kowa's time, it would be the biggest discovery in the history of mathematics in Eastern Asia. A handwritten manuscript entitled Zhui Shu is kept at Tokyo University Library “Œ‹ž‘å›{š¤ ‘ŠÙ. It is an 1897 copy from a manuscript of Okamoto's collections, so it must be Uchida's " Zhui Shu ". It, however, describes series, which was a very popular subject among Japanese mathematicians only after Seki Kowa developed Japanese algebra. Probably this MS. was forged much after Seki Kowa's time. Thus we can not agree with Uchida's claim. (e) Opinions concerning the Yang Hui Suan Fa (Yang Hui's Method of Computation) Fujiwara Shozaburo “¡Œ´¼ŽO˜Y (1881-1946) and Shimodaira Kazuo ‰º•½˜a•v (b. 1928) concluded that the book Seki kowa used was Yang Hui Suan Fa(18). There are two pieces of evidence. The first is that Seki Kowa hand-copied it in his youth (see section 1-2-a). The other is that the term Seki Kowa used to refer to his treatment of indeterminate equations is the same as "Senkan-jutsu" ãÆŠÇp (technique of cutting tube) of Yang Hui Suan Fa. Seki Kowa, however, did not burn the text book he used, rather, he retained it. And the explanation of solving indeterminate equations of this book is too simple to complete Seki Kowa's works on indeterminate equations (I will discuss in chapter 3). Thus I think that he used other text books, as well as Yang Hui Suan Fa, as sources in his development of method for solving indeterminate equations. Seki Kowa did not open his manuscript to other mathematicians, thus it is worth to consider the influence of Yang Hui Suan Fa for analysing his original works. Yang Hui Suan Fa is one of the best works about magic squares. Magic squares were a very popular subject for Japanese mathematicians, and most of them worked on this subject. Therefore, we will have to consider the influence of Yang Hui Suan Fa with respect to magic squares in chapter 2, in order to determinate how Seki Kowa and Japanese mathematicians influenced the design of magic squares beyond the treatment found in the Yang Hui Suan Fa . (f) New Opinion: Opinion concerning the Shu Shu Jiu Zhang (Mathematical Treatise in Nine Sections) We introduced some opinions, but these cannot perfectly explain the influence of Chinese mathematics (see table 4). In particular, these opinions do not explain Seki Kowa's treatment of indeterminate equations. Some mathematical books we have discussed above describe indeterminate equations, but they are too simple. Therefore we will consider the subject of whether Japanese mathematicians were influenced by Chinese mathematical arts. Because the best and the only work of indeterminate equations in China is Qin Jiushao's work, we will consider whether Seki Kowa's text book was Shu Shu Jiu Zhang. {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b categories b Seki's work b Opinions of Seki's text b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b a) verse b - b (Suan Fa Tong Zong ) b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b b) magic squares b 14) b Yang Hui Suan Fa? b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b c) indeterminate eqs.b 5)6)15) b - b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b d) series b 4)7)8)11) b Zhui Shu? b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b e) higher degree eqs.b 2)3) b Suan Xue Qi Meng b b b b Ce Yuan Hai Jing b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ b f) circles b 9)10)12) b (Jiu Zhang Suan Shu) b {\\\\\\\\\\\{\\\\\\\\{\\\\\\\\\\\\\{ Table 4 Opinions of Seki Kowa's text Notes (*1): Mikami Yoshio, 1932. (*2): Nihon Gakushiin, 1954, vol.2: 133-46. Hirayama Akira, 1959. Hirayama Akira et al (eds.), 1974. (*3): See Hirayama Akira et al (eds.), 1974: 14-24. (*4): See Hirayama Akira, 1959. (*5): Li Yan, 1937. (*6): See Nihon Gakushiin, 1954, vol.2: 142-3. (*7): (*8): Hosoi Sosogu, 1941: 93. (*9): Chinese characters are also used in Japanese, so with the help of some "Kaeriten" •Ô‚èêy (reading order symbol) and "Okurigana" ‘—‚è‰¼–¼ (traditional Japanese pronunciation to support reading Chinese), Japanese scholars could understand Chinese. The republished book of Suan Xue Qi Meng was published by Hisada Gentetsu and Haji Doun “yŽt“¹‰_ (?-?). (10): Endo Toshisada, 1896; 1981: 73-4, Mikami's comment. (11): Jochi Shigeru, 1991. (12): Kano Ryokichi Žë–ì‹œ‹g. 1902. "Seki Kowa 200-Nensai Kinen Honcho Sugaku Tsuzoku Koen-Shu" èF˜a“ñ•S”NÕ‹L”O–{’©É›{’Ê‘u‰‰W (Transcript of Lectures for Popularising Japanese Mathematics, in Remembrance of Seki Kowa on 200th anniversary of his death) (Nihon Gakushi-in, 1954, vol.2: 143). (13): Oba Osamu, 1967: 689. Moreover Ce Yuan Hai Jing Xi Cao ‘ªš¢ŠC‹¾×‘ (Comments of Ce Yuan Hai Jing) was also introduced in 1726 (Oba Osamu, 1967: 689) . (14): It is not Ce Yuan Hai Jing (Sea Mirror of Circle Measurement) itself, but it quotes the whole sentence of Ce Yuan Hai Jing, so Japanese mathematicians had access to the contents of Ce Yuan Hai Jing. (15): Nihon Gakushiin, 1954, vol.5: 428. (16): Oba Osamu, 1967: 687. (17): Nihon Gakushiin, 1954, vol.2: 143. (18): Nihon Gakushiin, 1954, vol.2: 7 and 17. Shimodaira Kazuo, 1965, vol.1: 188.