Xǔ Bózhèng 許伯政
Late-Yōngzhèng / early-Qián-lóng-period scholar with strong interests in calendrical-astronomical scholarship and classical-philological work on the Yìjīng. Birth and death years not securely recorded.
His principal extant works are the Yì shēn 易深 (a treatise on the Yìjīng, separately catalogued in the Sìkù) and the Quánshǐ rìzhì yuánliú 全史日至源流 (KR3f0030) in 30 juàn. The latter is his major calendrical-historical contribution: a systematic chronological reconstruction of the celestial events (rìzhì — solstices, qì seasonal-nodes, shuò new-moons, rùn intercalary months) recorded in the Confucian classics and the dynastic histories from the legendary Xuānyuán (Yellow Emperor) period through the late Míng (4,000+ years), with each event verified against post-Qīng calendrical computation (specifically the KR3f0018 Yùzhì lìxiàng kǎochéng of 1724) for chronological consistency.
The 提要 of KR3f0030 judges his methodological positions to be largely sound — he correctly advocated using 360 degrees for the celestial circle, 96 kè for the day, and rejecting the idea that the zodiacal palaces are fixed-stellar regions — but takes issue with two specific theoretical positions: his proposal that the annual real-year (suìshí 嵗實) decreases by 20 arc-seconds every 216 years, and his claim that the sun’s mean and apparent motions are equal at apsidal high-and-low points. The 提要 nonetheless commends the work’s chronological-reconstruction sections (the latter 30 juàn) as a valuable resource for future calendrical-historical research.