Jackson, Thomas Graham, Sir, 1835-1924 · Cambridge, University Press · leaf 135
arrow staircase winding ^ See Appendix to this chapter 2 From these squinch or oblique arches flying buttresses formerly sprangto the dome. They were removed by Fossati when he put his iron girdle roundthe dome. v. Antoniades, Einppaais &c. Plate KF. 92 S. SOPHIA, CONSTANTINOPLE [ch. vi The… … The effect of piercing these buttresses with arches in thegallery floor and that below is to convert them into flyingbuttresses; and their strength depends on their abutment,which is the stair turret and the short respond walls of thegallery arches. Strange to say removal of plaster for thepurpose…
