Concrete Arch - Pi In the Sky

The humble arch, so simple, so profound, so powerful The arch is Pi in the sky, a curved concrete crescent Supporting span of bridge or lintel Inspired by rainbow, waxing and waning moon Instilled by foot arch, caterary chain suspended Upper segment of circle, Pi with curved bowed legs. Compress concrete crush resolves, eliminates tension. Keystone at apex of arch locks stack array of blocks With Roman arch a symbol, old concept straggling time