organic geometry in gothic cathedral vaulted ceilings

gothic cathedral vaulted ceiling organic geometry architecture structural design ribbed vaults flying buttresses pointed arches tracery groin vault fan vaulting structure stone masonry verticality light stained glass rose windows nave aisle clerestory ambulatory choir apse piers spandrels transverse ribs diagonal lierne bosses pinnacles gargoyles construction load distribution buttress arched architectural innovation medieval ecclesiastical pattern historic artistic elements aesthetics analysis building techniques sacred space engineering craftsmanship