I hardly know how to begin thanking the many people who have helped with this book; lots of friends have pitched in with ideas and anecdotes and have lent me books and photos. I’d like to mention in particular the French ones, for I’m sure it must have required extra patience on their part to fill in a backward American on all the things a French person already knows: Mme. Philippe Aghion, Annick Baudoin, Mr. M. N. Bodiansky, Marie-Claude de Brunhoff, M. and Mme. E. de Bresson, David and Marcel Fleiss, the Fourest family, Hélène Maury, the staff of the Bibliothèque Mazarine, that of the Tabac des Beaux-Arts, Maître Jean-Jacques Ploquin, Mme. V. Debieuvre; and then, American friends who know a lot about the neighborhood: Mary Blume, Leonard Pitt, Arthur Hall Smith, Sally Williams-Allen, Drusilla Walsh. From afar, Diana Ketcham. Members of my family: two architects—Amanda Johnson and her husband, architect Jean-François Blassel—and art historian Darcy Tell have clarified various architectural mysteries for me. John Murray has been a cheerful companion on neighborhood walks. I’ve mentioned in the text and afterward a number of books that have been invaluable. It goes without saying that mistakes are mine alone.