According to Wikipedia, Devonshire Place has a history of literary residents.  Much of it is now filled with doctors and dentists.

Arthur Conan Doyle, creator of Sherlock Holmes, had his first doctor’s office at No. 2 Devonshire Place. William Beckford, author of the Gothic novel Vathek, lived at No. 4. Matthew Lewis, author of another Gothic novel, The Monk, lived at No. 9 and William Rothenstein lived at No. 10.

Timothy hung from the railings by one of the street signs.