Sentence Examples with the word semicircular arch

Externally it is an irregular octagon, each face consisting of a lower storey with a semicircular arch (in three cases occupied by a portal), with sculptures by Antelami, four tiers of small columns supporting as many continuous architraves, and forming open galleries, and above these (an addition of the Gothic period) a row of five engaged columns supporting a series of pointed arches and a cornice.