Jackson, Thomas Graham, Sir, 1835-1924 · Cambridge, University Press · leaf 279
y...•. AiiiLDi MOSAICS AT S. COSTANZA—ROME … CH. xiii] ROME 193 closed with a wooden roof. The dimensions are not such s. stefanoas to make the latter plan difficult, and it is not easy tounderstand why in 772 Pope Adrian I built an arcadeof three arches across the diameter of the circle. Theyare carried by two enormous granite columns…
