Sextant

  The Sextant, was made in the eighth to twelfth year of the reign of Emperor Kangxi (1669-1673), under the supervision of the Belgian missionary Ferdinand Verbiest. This instrument weighs 802 kilograms and is 3.274 meters high, located on the top platform of Beijing Ancient Observatory. It is mainly used to measure the angular distance of any two celestial bodies within 60 °and the angular diameter of the sun and moon.