After two further unsuccessful attempts at chairs of natural philosophy (one in St Andrews and one in Edinburgh) he was appointed as professor of mathematics at Edinburgh in 1805 after a bitter dispute, since he was not ordained by the Church.
Pagkatapos ng dalawang karagdagang nabigo pagtatangka sa upuan ng mga natural na pilosopiya (isa sa St Andrews at isa sa Edinburgh) siya ay hinirang bilang propesor ng matematika at Edinburgh sa 1805 matapos ang isang mapait na alitan, dahil siya ay hindi ordained sa pamamagitan ng Iglesia.