Set 10 | 90 : Ancient Star Observatory

Ancient Star Observatory

The Tower of Guo Shoujing is an impressive astronomical instrument. It allowed observers to measure the height of the sun, moon and stars above the horizon to a high accuracy. For its date 1276 ACE it is the most advanced instrument of the time.

A Gnomon in its simplest form is a vertical stick that is used to measure shadow. This can then take note of the shortest shadow (mid-summer) and the longest shadow (mid-winter). The advanced instrument at Dengfeng used a crosshair and water (as an accurate level) so that the motions of the heavens could be measured to five decimal places. A feat not achieved in Europe for another five hundred years.

Dengfeng Observatory is located within the Zhougong Miao temple some 85kms south-east of Luoyang, Henan Province.