In the summer of 1813 Cox was appointed as the drawing master of the Royal Military College in Farnham, Surrey, but he resigned shortly afterwards, finding little sympathy with the atmosphere of a military institution. Soon after that he applied to a newspaper advertisement for a position as drawing master for Miss Crouchers' School for Young Ladies in Hereford and in Autumn 1814 moved to the town with his family. Cox taught at the school in Widemarsh Street until 1819, his substantial salary of £100 per year requiring only two-day's work per week, allowing time for painting and the taking of private pupils.