A Life for the Stars

From the back cover of the Avon third printing: "A city launches itself into the galaxy! The noise was horrifying. He had never heard anything even a fraction as loud, but there could be no doubt about what it was: the city's spindizzies were sounding the alert. Then the whole city seemed to be rocking heavily, like a ship in a storm. At one instant, the street ended in nothing but sky; at the next he was staring at a wall of sheared earth, its rim looming cliff-like, fifty feet or more above the new margin of the city; then the blank sky was back again -"