John Knowles (1781-1841), English author. Knowles became a clerk in the surveyor's department of the Admiralry, and wrote books on the latest thinking on naval architecture. His studies led to being elected a Fellow of the Royal Society in 1822. He was a close friend of the painter Henry Fuseli, and on the latter's death published a biography and soem collected writings by Fuseli. Knowles, who never married, was one of the founding members of the Athanaeum Club in London.