In 1630 , William Oughtred of Cambridge invented a circular slide rule , and in 1632 combined two handheld Gunter rules to make a device that is recognizably the modern slide rule .
In 1630 , William Oughtred of Cambridge invented a circular slide rule , and in 1632 he combined two Gunter rules , held together with the hands , to make a device that is recognizably the modern slide rule .