I am and, for as long as I can remember, I have always been a poor visualizer. Words, even the pregnant words of poets, do not evoke pictures in my mind. No hypnagogic visions greet me on the verge of sleep. When I recall something, the memory does not present itself to me as a vividly seen event or object. By an effort of the will, I can evoke a not very vivid image of what happened yesterday afternoon, of how the Lungarno used to look before the bridges were destroyed, of the Bayswater Road when the only buses were green and tiny and drawn by aged horses at three and a half miles an hour.