11. The two small spiral stairs installed in 1958 are aluminum. 12. Developments in manufacturing and design have led to the introduction of kit form spiral stairs . 13. The rear verandah and viewing platform was enclosed and roofed and the spiral stair removed. 14. She handed Samantha to Dorothy Davenport, her nanny, and lead Wright to the spiral stairs . 15. A fourth smaller-diameter shaft accommodated an emergency spiral stair . 16. Spiral stairs mount to a platform from which visitors can gaze into the kidney-shaped bowl.17. The lower floor was a chapel, with a spiral stair leading up to the library. 18. The paired spiral stairs were unique to this area but not extraordinary in Palladio s designs. 19. There is an entrance and a new spiral stairs to the tower in the west wall. 20. To maintain headroom some spiral stairs have very high rises to support a very short diameter.
