From Horsley, Northumberland, he was one of John Wesley's first lay preachers and one of those invited to attend the fourth Conference in 1747. He had been pressed as a soldier and imprisoned, described by Tyerman as 'one of Wesley's untaught itinerants'. His mathematical and mechanical gifts caused Wesley to declare him to be 'as great a genius as Sir Isaac Newton'. He was also artistically gifted and engraved a portrait of Wesley as the frontispiece to his <span class="font-italic">Explanatory Notes</span>. He married Dorothy Furly, sister of the Rev. Samuel Furly and one of John Wesley's frequent correspondents. When he ceased to travel because of failing health, he became Wesley's printer.