People want to find order and beauty in the past, and the heritage industry is devoted to making sure they do. Offering to smooth out the relation between then and now, it only succeeds in holding the past in inverted commas, as between silver sugar tongs. When the grandeur and importance of historical sites is emphasized, the humble tourist who knows his place goes into the gift shop and looks at postcards, representations of the thing he feels unqualified to confront. The ground has been prepared for him and he has been set up to react. “Visitors faint here,” we were told, in the “Haunted Gallery” at Hampton Court.

If you want to think freshly about history you need to resist direction. Even if you avoid the tourist sites you can’t escape nagging. There is so much writing on the streets: walk don’t walk, turn don’t turn. There are symbols and suggestions on every wall, every post: interpretive screens between yourself and your subject. So when, as an author, you try to ground your project through topography, you may need to go against the flow, drag your heels, lurk in doorways like a child detective. Occasionally you feel you have caught the past unawares: in the depth of the Wiltshire countryside in a corner of the house called Wolfhall, or in a London street where the disengagement of strangers, their bustling preoccupation, creates a momentary void.