Brock published 109 illustrations in Punch between 6 February 1901 and 30 March 1910. He output in Punch tapered off after 1905 and he did not publish any more work in Punch after 1910. Brock continued to work on book illustration and on portraits. Some of the portraits by Brock in national collections date from the 1920. He continued to illustrate books right up until hid death, with Gunby Hadath's "Pamela: A Story for Girls" (1938) being one of the last books he illustrated. Books he was working on at the time of his death were completed by other illustrators. Brock was one of the twenty leading illustrators selected by Percy Bradshaw for a portfolio in his 1917/1918 "The Art of the Illustrator".