The Roman arch underwent a significant modification in the center Ages from the evolution of the pointed arch, which delivered a robust skeleton resting on effectively-spaced piers. The massive, rigid masonry constructions in the Romans gave way to soaring vaults supported by exterior flying buttresses (external bracing). A least requirement https://f004.backblazeb2.com/file/DigitalAsset/westhillmasonry/Hardscape-Contractors.html