In a top-story bedroom in an old-fashioned house in a northern suburb of London, a girl of fourteen was kneeling on the floor, turning out the contents of the bottom cupboards of a big bookcase. Her method of doing so was hardly tidy; she just tossed the miscellaneous assortment of articles down anywhere, till presently she was surrounded by a mixed-up jumble of books, papers, paint-boxes, music, chalks, pencils, foreign stamps, picture post-cards,...