Astronomical Observation

Astronomical observation, located in Gaocheng town 12 km southeast of Dengfeng city has Songshan and Qishan on its north and south respectively, boarding the Yin River. The observation together with Zhougongcejingtai observation and Zhougongci temple comprises an intact courtyard which accommodates a dozen astronomical instruments. Astronomical observation is the only existing and most intact astronomical observation in China and one of famous astronomical buildings in the world. It has been included in the first group of key national protection relics in 1961. Astronomical observation, built during the period from the 13th and 16th year of Yuan Dynasty, has a history of more than 730 years. With diligent measurements and calculations of a great many scholars including Guo Shoujing and Wang Xun, the most advanced calendar of that period in the whole world, Shoushili had been published in 1281. Shoushili has calculated the length of a year as 365.2425 days, whose accuracy is as precise as today’s Gregorian calendar and 26 seconds different from present calendar. However, it shall be taken into consideration that Shoushili is 300 years earlier than Gregorian calendar. The observation, a tall brick and stone building is comprised of inverse bucket shaped body and Liangtianchi, an instrument to measure the lengths of the sun shades. The observation has not only stored gui and biao, ancient instruments to measure the sun shades, but also represented the most developed techniques to measure the lengths of the sun shades since Zhougong’s method. Hence, the observation is of high significance for the researches on Chinese astronomical and architectural history.