Yǔnlù 允祿
Original name Yìnlù 胤祿, changed to Yǔnlù 允祿 after the accession of his elder brother Yōngzhèng (taboo on the yìn 胤 character of the imperial generation-name); studio-name Àiyuè zhǔrén 愛月主人 (“Master of the Loved Moon”). Sixteenth son of the Kāngxī emperor (1654–1722); born Kāngxī 34 (1695), died Qiánlóng 32 (1767).
Adopted in 1709 by the imperial uncle Boluo 博洛 (the childless Prince Zhuāng of the second rank, Zhuāng qīnwáng 莊親王), thereby inheriting in 1723 the Héshuò Zhuāng qīnwáng 和碩莊親王 hereditary princedom upon his brother Yōngzhèng’s accession. Held the title for 44 years; one of the most institutionally consequential of the Kāngxī-Yōngzhèng-Qián-lóng-period imperial princes. After Yōngzhèng’s death in 1735 he served as one of the four Regents (fǔzhèng dàchén 輔政大臣) for the underage Qiánlóng emperor (1735–1740); fell from favor in 1740 over conspiracies attributed to Pingjun and Hongxi, but retained his princedom and titular ranks.
Yǔnlù’s lasting intellectual contribution was as the imperial editorial director of the great Kāngxī-Yōngzhèng-period scientific-mathematical synthesis, the Lǜlì yuānyuán 律歷淵源 (Foundations of Music and Astronomy), in 100 juàn total. The project was chartered by Kāngxī in 1713 (Kāngxī 52); completed and printed under Yōngzhèng’s reign in 1724 (Yōngzhèng 2). Yǔnlù — then 18 years old when chartered, 28 when published — served as the senior imperial-prince director (chéngzhǐ zuǎnxiū 承旨纂修, “by-imperial-order chief compiler”), with his elder brother Yǔnzhī 允祉 (the 3rd son, formerly Yìnzhī 胤祉) as co-director. The actual scholarly compilation work was done by a substantial team of Hànlín scholars and Qīntiānjiān officials: Hé Guózōng 何國宗, Méi Juéchéng 梅㲄成 (grandson of Méi Wéndǐng), Wèi Tíngzhēn 魏廷珍, Wáng Lánshēng 王蘭生, Fāng Bāo 方苞, Míngāntú 明安圖 (the Mongolian mathematician), Hé Guódòng 何國棟, and many others, including the Jesuit consultants Kilian Stumpf 紀理安 and Ignaz Kögler 戴進賢 (in the post-1715 phase).
The Lǜlì yuānyuán comprises three principal parts:
- 歷象考成 Lìxiàng kǎochéng (Investigation of the Calendrical Phenomena, KR3f0018) — the astronomical-calendrical synthesis, in 42 juàn
- 律呂正義 Lǜlǚ zhèngyì (Correct Meaning of the Pitch-Pipes) — the music-theoretical synthesis, in 5 juàn
- 數理精蘊 Shùlǐ jīngyùn (Essential Principles of Mathematics) — the mathematical synthesis, in 53 juàn
Yǔnlù was also chief director of the Yùzhì lìxiàng kǎochéng hòubiān 御製歷象考成後編 (KR3f0019, 1742, 10 juàn) — the Qián-lóng-period revision incorporating Keplerian elliptical orbits, replacing the Tychonic uniform-circular orbits of the original Lìxiàng kǎochéng; and of the Qīndìng yíxiàng kǎochéng 欽定儀象考成 (KR3f0020, 1744, 30 juàn), the Qiánlóng instrument-and-star catalog updating the Schall-Verbiest Beijing instruments and stellar-position tables. Together these three works constitute the KāngxīYōngzhèngQiánlóng synthetic project of integrating European mathematical astronomy with Chinese state institutions.
Beyond the Lǜlì yuānyuán and its sequels, Yǔnlù was an important patron of Chinese music and theater (his name is associated with the compilation of imperial ritual music and the patronage of Beijing opera in its emergent form). His Qián-lóng-period archive at the Prince Zhuāng residence is documented as a significant private library and intellectual gathering-place.