Abridged Armilla
简仪
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.
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 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.
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 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;，
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”;
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.
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”。
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.
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。
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.
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。
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.
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。
The equatorial mounting，invented by the Chinese，was somewhat 500 years earli-er than like devices createdin Europe
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。