Torquetum Notes References Borgarsyssel Museum, Sarpsborg, 2003 Norwegian edition, and 2008 English edition (available from the museum). Further reading External links The search for Rasmus Sørnes 4th clock Prague Astronomical Clock A modern, online astronomical clock Les Cadrans Solaires (Sundials), also showing European astronomical clocks MoonlightClock.com – Handmade Astronomical Clocks Festraets’ astronomical clock Clock Clock Clock Chinese inventions English inventions Greek inventions Arab inventions Hellenistic engineering History of astrology Historical scientific instruments Italian inventions