In 1871 he took a mastership at Edinburgh Academy, but resigned in 1873 and returned to London. He was a writer for the rest of his life, in areas including social and educational topics, and European politics. As a journalist he worked on The Globe, the Pall Mall Gazette, and the St. James's Gazette under Frederick Greenwood. He contributed to The Athenæum, Saturday Review, and the English Illustrated Magazine. He wrote long-term for The Graphic and Daily Graphic, and for some time was on the staff of Nature magazine.[1]
From 1880 Sime lived in Bedford Park, London, at 1 Queen Anne's Grove, in a house which he had commissioned. He died there of influenza, on 20 March 1895, and was buried on the eastern side of Highgate Cemetery.[1]
Sime married, on 6 October 1865, Jessie Aitken Wilson, youngest sister of Sir Daniel Wilson, who was professor of History and English Literature at the University of Toronto, and of George Wilson of Edinburgh University. His daughter, Jessie Sime was a novelist who emigrated to Montreal, Canada and wrote several Canadian themed books.[5]