The Reverend McKnight ran a preparatory school for the sons of noblemen at Purton and at the Manor House in Lydiard Millicent from 1852 to 1879 when he left the parish and the school was closed. The Reverend served as the Curate in Lydiard Millicent from 1851. He gave talks in the Mechanic's Institute in Swindon as a Liberal and wrote for the Old Swindon Advertiser (he had secured a financial interest in the newspaper). He helped to establish a Liberal Association in Cricklade.