The Ecliptic Armilla 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 was the first astronomical instrument with an ecliptic coordinate system in China. The Ecliptic Armilla measures six feet in diameter and is composed of several layers: a meridian circle,a zodiacal circle, a longitude circle and a polar circle.Its structure was based on the Tychonian ecliptic armillary sphere and is similar to the equatorial armilla. The ecliptic armilla was used to measure the ecliptic longitude differences and latitudes of celestial bodies. The ecliptic coordinate system was a typical European astronomical observation method and was simpler than the equatorial coordinate system when observing the sun and the planets.
Click here to view the PDF version