The Chinese Imperial Astronomical Bureau: Form and function of the Ming Dynasty 'Qintianjian' from 1365 to 1627

All polities which ruled China in the Imperial period maintained an Astronomical Bureau. This Bureau served the ruler by fulfilling the requirements of political cosmology. In this tradition view, the ruler was the Son of Heaven, legitimated by possession of the Mandate of Heaven, and was responsible to the Will of Heaven. The Bureau served this ideology by: (1) monitoring, interpreting, and, when possible, predicting celestial phenomena considered as commentary on imperial action. (2) preparing the annual luni-solar calendar on the basis of the officially sanctioned calendric system. These services upheld the link between the ruler and the heavenly realm. The Bureau also was responsible for government time keeping devices and for the selection of auspicious times to observe certain ritual events.; To maintain a literal alignment of the calendar with heaven and to forecast eclipses, as demanded by Chinese political cosmology, the Bureau was constantly involved in debates and trials over calendric system reform. Successive refinements in these systems included the incorporation of precession and true lunar-solar motion. However, development of the calendric system took place without use of spherical trigonometry. Ptolemaic influences were resisted in both the Tang and the Yuan, when a technical peak was attained with the Season Granting system. Calendric reform was irregularly discussed in the Ming but administrative regulations, meager resources, the lack of a clearly superior alternative, and particular events combined to prevent action before the fall of the dynasty.; The major source for the chapters devoted to the Ming was the Ming Veritable Records. Analysis of Bureau notices of Mercury preserved there suggest the ideological purpose of this duty did not lead to falsification of observations. Evaluation of Bureau performance in the prediction of eclipses indicates how technical, ideological, and practical factors combined to determine the official judgement of this aspect of Bureau operations. Examination of personnel records verify that bureau personnel, as decreed by the Ming founder, were prevented from advancement beyond the Bureau. The installation of special supervisors from the Bureau itself and from other government posts largely failed to improve managerial or technical operations.