조선시대 觀天臺와 日影臺의 연혁

The name of gwancheondae(觀天臺) means a sky-observing stand. It was a stand for ganeui(簡儀: a kind of torquetum) or soganeui(小簡儀: a kind of small torquetum). The name of ilyeongdae(日影臺) means sun-shadow stand. It was a stand for ilgu(日咎: sundial) or ilseongjeongsieui(日星定時儀: a kind of astrolabe). Ilseongieongsieui was an astronomical clock used for checking the nearby clepsydra for day and night. There is a stone stand designated for treasure No. 851 in Changgyeong Palace(昌慶宮). It is known as a gwancheondae for soganeui, but it is not a gwancheondae but an ilyeongdae for ilseongjeongsieui. It is the only stand for ilseongjeongsieui, and the stone stand located in Hyundae office building in Gye-dong is the only stand for soganeui remained till now.