Witold Rybczynski, emeritus professor at the University of Pennsylvania, has written widely on architecture and design. A Clearing in the Distance, his biography of Frederick Law Olmsted won the J. Anthony Lukas Book Prize, and he has also been awarded the Vincent Scully Prize and the National Design Award. His latest book is "Now I Sit Me Down: From Klismos to Plastic Chair, A Natural History," out in paperback this month.