Lowrie, William (2007). Fundamentals of Geophysics. London: Cambridge University Press. стр. 281. ISBN978-0-521-67596-3. „Early in the Han Dynasty, between 300–200 BC, the Chinese fashioned a rudimentary compass out of lodestone ... the compass may have been used in the search for gems and the selection of sites for houses ... their directive power led to the use of compasses for navigation”