Quadrant

Quadrant

  The Quadrant, also known as the zenith sector, 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 2483 kilograms and is 3.611 meters high, located on the top platform of Beijing Ancient Observatory. It is mainly used to measure the horizontal height or zenith distance of celestial bodies.