Jì Lì’ān 紀利安 (also 紀理安) / BernardKilian Stumpf, S.J.
German Jesuit. Born Würzburg (Bishopric of Würzburg, Holy Roman Empire), 13 September 1655; died Beijing, 24 July 1720. The Chinese name Jì Lì’ān / Jì Lǐ’ān renders “Kilian” by phonetic approximation, with the Jì surname (free choice).
Joined the Society of Jesus 1671; sent to the China mission 1689, arriving Macao 1694 and Beijing 1696. Trained in mathematics, astronomy, and instrument-construction; held the office of Director of the Qīntiānjiān (Imperial Astronomical Bureau) from approximately 1715 (succeeding Antoine Thomas) until his death in 1720, when he was succeeded by Ignaz Kögler (戴進賢).
His principal contribution was the construction (Kāngxī 52, 1713) of the Dìpíng jīngwěi yí 地平經緯儀 (Horizontal Longitude-and-Latitude Instrument) for the Beijing Astronomical Observatory — a combined-function instrument unifying the horizon-quadrant and the limb-quadrant into a single device. This was one of the principal mechanical-astronomical innovations to the Verbiest-era Beijing instruments, simplifying horizon-coordinate observation considerably. The instrument is celebrated in the KR3f0020 Yíxiàng kǎochéng 儀象考成 imperial preface (1756) by the Qiánlóng emperor as “especially convenient in use”.
Stumpf also assisted in the early phases of the Kāngxī mathematical academy at the Méngyǎng zhāi, contributing to the collection-and-explanation of European mathematical-and-astronomical materials that would form the basis of the KR3f0018 Lìxiàng kǎochéng of 1724.