How to read the atlas
Time runs left → right (1200 BCE → 1911 CE, linear, labelled every 250 years with lighter century lines). Vertical rows are dynasties and the institution that ran across them: the pre-imperial records, then the Han, Six Dynasties and Tang, Song, Yuan, Ming, and Qing periods of the Astronomical Bureau, plus a bottom row for the political events that shaped the work. Each glyph sits at its event's date on its row; bars are people, showing the years a figure was active.
Three dashed jade lines mark the entry of foreign methods: Indian astronomy at the Tang court (718), Islamic astronomy under the Yuan (1267), and European astronomy from 1601. Dates are Common Era on the axis; each card also gives the sexagenary (gānzhī) cycle year, the sixty-year stem-and-branch reckoning used throughout the record.
Glyph shape is the kind of contribution: filled circle = observation or record, open circle = treatise or calendar, square = founding of an institution, triangle = instrument, diamond = political event. Glyph fill colour matches the dynasty stripe.
The dynasties, briefly
Three things that set Chinese astronomy apart
The first is the record itself. Because eclipses, comets, novae, and sunspots were logged by a state bureau as a matter of duty, China produced the longest and most systematic run of dated observations before the telescope. Modern work on historical supernovae, the Crab Nebula, cometary orbits, and the long-term slowing of the Earth's rotation all draw on these records.
The second is the calendar as government. The tradition's central problem was not a geometric model of the cosmos but an accurate luni-solar calendar, since issuing one was an imperial prerogative. Chinese astronomy was therefore strong in numerical methods — interpolation, the fitting of observed motions — and used equatorial coordinates and the twenty-eight lunar lodges rather than the ecliptic and zodiac of the western traditions.
The third is exchange. The Bureau repeatedly took in outside methods without losing its own institutional continuity: Indian calendrical astronomy under the Tang, the Maragha-derived instruments and Islamic tables of the Yuan and Ming, and finally the European astronomy that Jesuit mathematicians brought to the Qing Bureau — the point at which this volume meets Volume I.
Methodology — what counts, what does not
Inclusion. An entry qualifies if (a) the work was done within the Chinese astronomical tradition between roughly 1200 BCE and 1911 CE, and (b) it was a primary contribution to observation, calendar-making, instrumentation, or the institutional record. The emphasis is on positional and calendrical astronomy and on the observational archive, which is where the tradition's distinctive strength lies.
Astronomy and the state. Calendar-making and observation were functions of the imperial Astronomical Bureau, and for much of the period private astronomical study was restricted by law. The atlas treats the institutional and the individual together, since in China they are hard to separate; astrological interpretation of omens is noted where it bears on the observational record but is not itself catalogued as astronomy.
Sources and dating. Entries cite a primary source — a dynastic-history treatise (the lǜ-lì zhì), a calendar text, an instrument description — or a modern critical study, with pinyin transliteration and characters. Dates follow the standard reference literature (Needham's Science and Civilisation in China vol. 3, Sivin, Cullen, and the dynastic histories). Where a date or attribution is contested, the card says so.
Overlap with Volume I. The Jesuit astronomers who ran the Qing Bureau (Schall, Verbiest) appear in Volume I as members of their order; here they appear as directors of a Chinese institution. The two treatments are complementary, and the relevant entries cross-reference each other.
Companion RAVEN material
The Chinese record of “guest stars” is a working input to modern astrophysics: the 1054 supernova that produced the Crab Nebula, and the earlier events of 1006 and 185, anchor the historical-supernova entries traced in the RAVEN Catalogs. Guo Shoujing's instruments and Su Song's clock-driven armillary belong to the ground-instrument lineage of the Platforms Atlas. Two seams join this volume to the others: the Indian calendrical astronomy that entered the Tang court in 718 comes from the tradition of Volume III, and the Jesuit reform of the Qing Bureau is the same story told from the institution's side in Volume I.