Hú Dǎn 胡亶
Sobriquet Lìzhāi 勵齋. Native of Rénhé 仁和 (Hángzhōu prefecture, Zhèjiāng). Birth and death years not securely recorded; flourished in the early Kāngxī period (1660s-1670s).
A private scholar with a particular specialty in observational astronomy. Wáng Zhuó’s 王晫 Jīnshì shuō 今世説 (a Kāngxī-period biographical compendium modeled on the Shìshuō xīnyǔ) describes him as “broadly mastering the various books, especially refined in the Tiānguānjiā (Celestial-Officers School) discourse — for solar-and-lunar eclipses, stellar positions, computation-and-prediction, [he was] without the slightest omission. In Chángān [Beijing] he debated repeatedly with the Western specialists at the [Qīntiānjiān] Bureau; the multitude all sighed in admiration”. His direct astronomical confrontations with the Beijing Jesuit Bureau staff (presumably Verbiest 南懷仁 and his assistants in the late 1660s) were apparently substantive and impressive enough to circulate in early-Kāngxī biographical literature.
Of his works only the Zhōngxīng pǔ 中星譜 (KR3f0022, 1 juàn, completed Kāngxī 8 / 1669) survives in the Sìkù; the Sìkù 提要 records his lost works as the Zhōutiān xiànjiè tú 周天現界圖 (Diagram of the Celestial Boundaries) and the Bùtiān gē 步天歌 (Step-the-Heavens Song — presumably his own version of the long-standing Bùtiān gē mnemonic-poem tradition).