Customers of second-hand booksellers, such as I, are also a rum lot. What kind of person spends two-and-a-half hours in a shop and then havers indecisively over whether he really wants a copy of Augustine Birrell’s (unjustly) forgotten essays marked at £3? If he fails to buy it, he will regret it the moment the shop has closed or he can’t get back to it. If, on the other hand, he (and customers are almost always he) buys a book that his wife will find outrageously expensive by comparison, say, with a pair of shoes, or even a single shoe, he will ask the bookseller to rub out the price. All booksellers are so familiar with this pattern that they are ready with their rubbers even as their customers buy.