明清月晷星晷结构考

Research on the Structure of Moon-dial and Star-dial of Ming and Qing Dynasties

在搜集尽可能完备的文献记载和文物实物信息的基础上,借鉴前人研究的成果,以梳理明、清月晷和星晷的结构为主线,辅以复制模型和模拟观测等手段,对明、清月晷和星晷的结构和用法做一全面的分析考证,对晷盘上各种刻度的划分、起始位置、走向也作了详尽的分析和辨正。月晷可分为"早型"、"晚型"两类,星晷分为"地盘固定型"、"全动型"两类,操作方式差别都很大。通过模拟观测,发现月晷的测时误差较大,而星晷的误差较小;通过实地考察和模拟观测,发现故宫养性殿前清代石质日月晷的某些刻度是错误的。根据研究结论还提出了月晷、星晷的复制推荐。

On the base of collecting the records of almost all the documents and the cultural relic about moon-dial and star-dial, and also the base of using the works of our predecessors for reference, this article studies and analyzes the structure and usage of moon-dial and star-dial of Ming and Qing Dynasties. The main clue is to sort out their structures, and the secondary clue is to reproduce their models and observe with the models. The article also analyzes how the scales are divided, where the original points are and which directions they tend to. Moon-dial can be divided into two types： the early type and the late type. Star-dial can also be divided into two types： the type of the fixed under-dial and the type of the both dials moving. The ways of the operation of the four types are different. When we observe with the models, we find that moon-dial have comparatively more errors but star-dial less. Furthermore, we find that some scales of the stone sun-moon-dial standing in front of the Yangxing Palace in the Forbidden City are not right. Finally, the article puts forward the suggestions of reproducing moon-dial and star-dial.