These cathedrals were built with towering spires, pointed arches and flying buttresses giving impressions of harmony and luminosity. One of the major accomplishments of the 12th and 13th centuries was to develop the engineering mastery of the ribbed vault, pointed arch and flying buttress to create a great cathedral that is at once taller, lighter, wider, and more elegant than the ones before. Even though the pointed arch could support more weight than its predecessors, there was still the problem of finding a way to support the heavy masonry ceiling vaults over wide spans. In order to support the outward thrust of barrel vaults, vertical support walls have to be very thick and heavy...
