On the Revised Edition of the Kōwa tsūreki by Nakane Genkei (Study of the History of Mathematics 2021)

In the fourth year of Shōtoku (1714), calendrical calculator Nakane Genkei (1662-1733) published the Kōwa tsūreki (Imperial Japanese Lunisolar Calendar). During his lifetime and even after his death, this calendar was published with an increase in the months and the years, and was widely supported by people as the standard book of the lunisolar calendar. The revised edition of the Kōwa tsūreki, published around 1724, included a foreword by the great Confucian scholar Ogyū Sorai (1666-1728), and the introductory that appeared the first edition was corrected. The first half of the introductory by G. Nakane was a criticism of his teacher Shibukawa Harumi (1639-1715)'s research on the ancient calendar. In previous studies of the Kōwa tsūreki, there has been no mention of the foreword by S. Ogyū and criticism of H. Shibukawa. Therefore, this paper will examine the foreword from the perspective of the history of Japanese calendar, and also clarify the criticism of H. Shibukawa by G. Nakane