简仪
Abridged Armilla
简仪为元代(1271一1368)天文学家郭守敬(1231一1316)于公元1276年创制的一种测量天体位置的仪器。
The Abridged or simplified Armilla was invented in 1276 by Guo Shoujing (1231一1316)，an astronomer in the Yuan Dynasty(1271一1368)，for measuring positions of celestial bodies.
该仪器的结构和使用都比浑仪简单，而且除北极星附近以外，整个天空一览无余，故称简仪。
The apparatus is simpler than the armillay sphere in terms of structure and application，and it gives a panorama of the celes-tial sphere except the part around Polaris，so it is called Abridged Armilla.
简仪的主要装置是由两个互相垂直的大圆环组成，其中的一个环面平行于地球赤道面，叫做“赤道环”;
The primary structure of Abridged Armilla contains two large rings that are per-pendicular to each other, of which one is parallel with the equatorial plane and is accordingly called“equatorial ring;，
另一个是直立在赤道环中心的双环，能绕一根金属轴转动，叫做“赤经双环”。
and the other is a double-ring which is per-pendicular to the center of the equatorial ring，revolving around a metallic shaft，and is called“right ascension double-ring.
双环中间夹着一根装有十字丝装置的窥管，相当于单镜筒望远镜，能绕赤经双环的中心转动。
The double-ring holds within itself a sighting tube with crosshairs，which equals to a monocular and revolves around the center of the right ascension double-ring.
观测时，将窥管对准某颗待测星，然后在赤道环和赤经双环的刻度盘上直接读出这颗星星的位置值。
During observation，the sighting tube is targeted at a certain star, thus the positional value can be read out at the dials of the equatorial ring and the right ascension double-ring.
有两个支架托着正南北方向的金属轴，支撑着整个观测装置，使这个装置保持着北高南低的形状。
Two stands are supportingthe metallic shaft that exactly directs at the south and the north，bracing the entire observing unit to a position in which the north part is higher than the south part.
这是我国首先发明的赤道装置，要比欧洲人使用的赤道装置早500年左右。
The equatorial mounting，invented by the Chinese，was somewhat 500 years earli-er than like devices createdin Europe