摘要
明代崇祯年间曾制作过平面日晷和星晷。日晷使用了三角形的表，其斜边指向北天极，观察其在阳光下影子的位置就可在不同季节确定时刻，解决了我国古代地平式日晷长期存在的问题。该日晷还能确定当时所处的节气。星晷采取了重盘的结构，按照当时所处节气调整盘间的位置后可观测两颗特定的恒星，以有效地确定时刻。这两台计时仪器是徐光启学习了西方有关知识后的创造性仿制．是东西方文化交流的结晶，在中国古代计时仪器发展史上具有重要的地位。
In Chong Zhen years of Ming Dynasty, some horizontal sundials and star dials were made. On the sundial, the triangular gnomon was used. The hypotenuse of the gnomon point at the north celestial pole. To observe the position on the dial of its shadow on the different date of a year, the time can be known. Used this gnomon, the problem that existed over a long time on the horizontal sundial in ancient China was solved. By the sundial the solar term can be known too. The star dials were adopted the structure of two overlaped disks.According to the solar term to adjust the relative position of the disks, the time can be known by observing two choosed stars. After studying the relative western knowledge, Xu Guangqi, the great scientist in Ming Dynasty, made these timing tools creatively. It was the crystallization of the exchange of eastern and western culthres. It has a important place in the history of timing tools in ancient China.
出处
《中国科学院上海天文台年刊》
1998年第19期183-187,共5页
Annals Shanghai Astronomical Observatory Chinese Academy of Sciences
关键词
日晷
星晷
计时仪器
天文学史
古天文仪器
明朝
sundial
star dial
timing tool
history of astronomy
ancient astronomical instrument
