The fire extinguisher; the airline safety card; the lifeboat. Until September 11, 2001, most Americans paid homage to these appurtenances of disaster with a sidelong glance, if at all. But John Stilgoe has been thinking about lifeboats ever since he listened with his father as the kitchen radio announced that the liner Lakonia had caught fire and sunk in the Atlantic. It was Christmas 1963, and airline travel and Cold War paranoia had made the...