Born in Manchester on 14 May 1759, Molineux studied at the school in Salford run by Henry Clarke.
There he learned John Byrom's system of shorthand, and before he was 17 he became a writing-master and teacher of accounts in King Edward VI's Grammar School, Macclesfield.
[1] Molineux resigned from the school in 1802, and died in Macclesfield on 15 November 1850, aged 91.
The editions of The Instructor published in 1824 and 1838 have a portrait of Molineux, engraved by Robert Cabbell Roffe from a painting by Scott.
Roffe was an engraver in London, whom Molineux taught shorthand by correspondence, and who became the author of another modification of the Byrom system.