angles appearances architectural architectural elements architecture base circular columns decorative fluted columns fluted pillars granite Greco-Roman modern pillars plinth shaft strength strong style support texture abstract aged appearance background concrete crack cracked cracking cracks damage damaged deteriorated deterioration fluted fluting garden garden-pillar gray grey lines mini-garden-pillar old pillar pot-pillar rough surface surfaces surfacing textured textures uneven variations varied various ineffective paint painted painting British Museum England english Great Britain historical history landmark London museum portico Portland stone