Whenever I look at an old sepia photograph or one of those amazing 19th century genre pictures like William Powell Frith's Ramsgate Sands, it is not the immediate images that grab my attention. Although the detail is often remarkable, in the case of Ramsgate Sands the attentive mother gently introducing her over-dressed child to the water or the seaside entertainer with his cluster of performing mice, it is the notion that these pictures can be viewed as frozen moments in time, part of a continuing narrative of life and action. Visual images evoke the past because they have the power to hold time in suspension, an image sustained ad infinitum. After one of my standard teaching...