Complex sentence: Discharged on health grounds in 1814 he then made a voyage to China in the Indiaman "Warley" and on return, with many sketches, was engaged in August 1816 as a decorator and scene-painter at the Royalty Theatre in Wellclose Square, London.
Split into simpler sentences: Discharged on health grounds in 1814 he then made a voyage to China in the Indiaman "Warley" and returned with many sketches. In August 1816 Stanfield was engaged as a decorator and scene-painter at the Royalty Theatre in Wellclose Square, London.