Beijing Ancient Observatory was first built in 1442 in the Ming Dynasty (1368 - 1644), and was the national observatory in the Ming and Qing Dynasty. This ancient pre-telescopic observatory, the most important one in China, was built about 14 meters in height. It has an observation history of nearly 500 years from Ming Dynasty to 1929 A.D, which boasts one of the oldest astronomical observatories in the world.
Covering an area of 10,000 square meters, the Beijing Ancient Observatory consists of a ten-meter tall brick Watching Star Platform and several bronze astronomical instruments lying atop. The observatory in itself is located on the roof of what is now, an astronomy museum. The 8 instruments equipped with western technology and Chinese local art design show us the exchange between the western and the magnificent western design.
The armillary sphere is an instrument used to measure the coordinates of the celestial bodies. This instrument is constructed of two bronze disks--one being known as the ecliptic armillary (for tracking the sun), and the other deemed the equatorial armillary (tracks bodies that are not the sun). The quadrant is an instrument built in 1673 and used in order to measures the altitudes and zenith locations of the celestial bodies. The theodolite is an instrument built in 1715 and used for measuring both altitude and azimuth coordinates of celestial bodies. The azimuth theodolite is a relatively similar instrument lacking only the ability to record altitude. The sextant is an instrument used for measuring the angular distance between celestial bodies, and is also used for measuring the angular diameter of the moon and sun. The celestial globe was built in 1673 and used to determine the time in which the celestial bodies will rise and set; as well as the altitude and azimuth of the bodies at any given time.
It was said that following the fall of the Northern Song Dynasty 1227, the victorious Jins transferred the ancient astronomical instruments from Kaifeng to the first observatory in Beijing in 1279AD; the succeeding invading Mongols under Kublai Khan built the second observatory in Beijing just north of the present observatory. With the fall of the Mongols, Zhu Yuanzhang, the first Emperor in the Ming Dynasty, transferred the instruments from Beijing to Nanjing. When the Yongle Emperor seized the power from his nephew, he did not dare to transfer the instruments to Beijing out of respect for his father who was buried in Nanjing. Instead he commissioned craftsmen to make wooden models of these instruments and had them cast in bronze, including the armillary sphere, the abridged armillary and the Yuan guibiao sundial.
In Kangxi and Qianlong periods in Qing Dynasty, the astronomical observatory added eight large-sized astronomical observatory equipment made of cooper one after another. They all adopted the European measurement and equipment construction. Those astronomical equipment had large body, and beautiful sculpt, excellent engraving. Except for the Chinese tradition characterized aspects like sculpt, flower decoration and craftwork, etc, the other aspects like graduation, cursors and construction also reflects the process and achievement of large-size astronomical equipment after the period of renaissance of the Western Europe. It is the historical witness of oriental and western culture exchanges. They are not only the practical astronomy observation equipment but also the incomparable historic culture relic treasures.
After 1949, Beijing Ancient Observatory became a part of Beijing Planetarium. It is the key national-relics protection unit now. It is the historical records of the longest successive observation period amongst the current existing ancient observatories in the world. Moreover, it also shares high reputation in the world due to its integrated building and completed equipment.