Editing Astronomical clock (section)

=== Su Song's Cosmic Engine ===
The [[Science Museum (London)]] has a scale model of the 'Cosmic Engine', which [[Su Song]], a Chinese [[polymath]], designed and constructed in China in 1092. This great astronomical hydromechanical clock tower was about ten metres high (about 30 feet) and featured a clock [[escapement]] and was indirectly powered by a rotating wheel either with falling water and [[mercury (element)|liquid mercury]], which freezes at a much lower temperature than water, allowing operation of the clock during colder weather. A full-sized working replica of Su Song's clock exists in the [[Republic of China]] (Taiwan)'s [[National Museum of Natural Science]], [[Taichung]] city. This full-scale, fully functional replica, approximately {{convert|12|m|ft|abbr=off|sp=us}} in height, was constructed from Su Song's original descriptions and mechanical drawings.<ref>{{cite web|url=http://www.nmns.edu.tw/nmns_eng/04exhibit/permanent/tower.htm|title=National Museum of Natural Science -> Exhibition -> Permanent Exhibits|work=nmns.edu.tw|access-date=9 October 2015|archive-url=https://web.archive.org/web/20180224052953/http://www.nmns.edu.tw/nmns_eng/04exhibit/permanent/tower.htm|archive-date=24 February 2018|url-status=dead}}</ref>