 It is the only remaining astronomical clock from the Joseon Dynasty.The clock was purchased from an antiques dealer some time before WWII by Mr Kim Seong-su 김성수 金性洙, the rich businessman and politician who founded Korea University.The historian of science Jeon Sang-Woon 전상운 全相運, who examined the device in 1962, assumed that it was the clockwork driven sphere known to have been made by Song Yiyeong 송이영 宋以穎 in 1669 for King Hyeonjong of Joseon 현종 顯宗, and the British historian of science Joseph Needham adopted this view, giving a detailed citation of the relevant Korean texts from that period, and a detailed description of the mechanism.