<Li> The Castle of Knowledge, containing the Explication of the Sphere both Celestiall and Materiall, etc . (London, 1556) A book explaining Ptolemaic astronomy while mentioning the Copernican heliocentric model in passing . </Li> <Li> The Whetstone of Witte, whiche is the seconde parte of Arithmeteke: containing the extraction of rootes; the cossike practise, with the rule of equation; and the workes of Surde Nombers (London, 1557). This was the book in which the equals sign was introduced . With the publication of this book Recorde is credited with introducing algebra into England with a systematic notation . </Li> <Li> a medical work, The Urinal of Physick (1548), frequently reprinted . </Li> <P> Several books whose authors are unknown have been attributed to him: Cosmographiae isagoge, De Arte faciendi Horologium and De Usu Globorum et de Statu temporum . </P>

Who was the first english mathematician who first used