Harness spent part of Christmas 1811 with Byron and another friend, Francis Hodgson, at Newstead Abbey but the friendship cooled so much immediately after, that there is no correspondence at all.
He was curate of Dorking 1814-16, and then preacher at Trinity Chapel, Conduit Street, London, and minister and evening lecturer at St. Anne's, Soho.
On the opposite side of Regent Square, Edward Irving's chapel was situated, and in 1831 Harness preached a pointed sermon entitled Modern Claims to Miraculous Gifts of the Spirit.
[1] On 1 March 1851 Harness acted as one of the stewards at the farewell dinner given to William Charles Macready In 1866 he was appointed Rugmere prebendary in St Paul's Cathedral, and preached there.
[1] While on a visit to one of his former curates, Edward Neville Crake, dean of Battle, Harness died in a fall down the stone staircase of the deanery, on 11 November 1869.
A brass tablet was erected to his memory in All Saints' Church, Knightsbridge, and a prize with his name was founded by the subscriptions of his friends at Cambridge for the study of Shakespearean literature.
His close friends included Sarah Siddons, Fanny Kemble, Mr. and Mrs. Charles Kean, Robert Southey, William Wordsworth, Miss Mitford, Catherine Maria Fanshawe, Joanna Baillie, Harriet Martineau, and Thomas Hope.