**Mei Juecheng** was a Chinese mathematician who edited and extended the works of his grand-father Mei Wending.

- He asked Li Guangdi to find the best mathematics books and in 1703 Li gave the Emperor Kangxi a copy of Lixue yiwen (Inquiry on Mathematical Astronomy) written by Mei Wending in 1701.
- Emperor Kangxi was greatly interested and summoned Mei Wending to an audience in 1703.
- By this time Mei Wending was seventy years old and he went to Baoding to meet Emperor Kangxi taking his grandson Mei Juecheng with him.
- From this time on Mei Juecheng played a major role in the compilation of mathematical and astronomical works.
- Mei Juecheng was appointed as Court Mathematician in 1712.
- In the following year the Emperor Kangxi established the Mengyangzhai (the Academy of Mathematics) and Mei Juecheng joined the team of people working on the compilation Yuzhi shuli jingyun (Treasury of Mathematics) which was published in 1723.
- Mei Juecheng and Chen Houyao (1648-1722) were the chief editors and they were assisted by He Guozong, Ming Antu and, in the early stages of the project, by Mei Wending.
- In particular, studying Western algebra enabled Mei Juecheng to decipher older Chinese mathematical treatises from the Song (920-1279) and Yuan (1206-1368) dynasties whose methods had been lost.
- Again Mei Juecheng was the leading academic in this project which, like the Treasury, followed the style of European works.
- In 1759 Mei Juecheng published Chishui yizhen (Pearls recovered from the Red River).
- The Jesuit missionary Pierre Jartoux (1669-1720) (known in China as Du Demei) introduced the infinite series for the sine into China in 1701 and it was known there by the name 'formula of Master Du'.
- Pearls recovered from the Red River was one of two chapters that Mei Juecheng appended to the works of Mei Wending that he was editing and republishing.
- Important work of Mei Wending on mathematics published in this collection included: Bisuan Ⓣ(Pen calculations), Chou suan Ⓣ(Napier's bones)), Du suan shi li Ⓣ(Proportional dividers) , Shao guang shi yi Ⓣ(Supplement to 'What width'), Fang cheng lun Ⓣ(Theory of rectangular arrays), Gougu ju yu Ⓣ(Right-angled triangles), Jihe tong jie Ⓣ(Explanations in geometry), Ping san jiao ju yao Ⓣ(Elements of plane trigonometry), Fang yuan mi ji Ⓣ(Circles and squares, cubes and spheres), Jihe bu bian Ⓣ(Supplement to geometry), Hu san jiao ju yao Ⓣ(Elements of spherical trigonometry), Huan zhong shu chi Ⓣ(Geodesy) and Qiandu celiang Ⓣ(Surveying solids).

Born 19 May 1681, Xuangcheng, now Xuanzhou City, Anhui province, China. Died 20 November 1763, China.

View full biography at MacTutor

Astronomy, Origin China

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive