“Haitfield House, Sowth Wawlk” was the instruction when he got into the cab, and continued his conversation with a colleague about futures, options and takeovers with an accent of Received English which would have made Brian Sewell sound like Del Boy. South Walk? “I’m not sure where Hatfield House is”, I ask. My passenger informs me that it might be Stamford Street. “Oh! Southwark”, with a silent W.