The Quadrant was completed in 1673, the 12th year of the Kangxi Emperor’s reign in the Qing Dynasty. It is one of the instruments designed by Ferdinand Verbiest.It is six feet in radius and was used for measuring altitudes or zenith distances of celestial bodies.The main part of the quadrant is a graduated quarter of a circle frame which is called the quadratic ring. A dragon design was carved inside the ring for balance.The vertical frame can revolve on the axis. The quadrant is modeled on the Tychonic version but with traditional Chinese design characteristics.


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