Jackson, Thomas Graham, Sir, 1835-1924 · Cambridge (Eng.) University press · leaf 344
or in themiddle ages the quarries of porphyry were unknown andhave in fact only been re-discovered lately. But with thesematerials almost anything can be done, and without themthe same effect is unattainable, as any one will know whohas tried to make a pavement of the same kind withother materials.… … S. FRANCESCA ROM AN A—ROME CH. xiii) ROME 209 Notice must also be taken of the baldacchini or Baidac-canopies of tabernacle work of which there are examples Rome^at S. Lorenzo, S. Clemente, and S. Giorgio in Velabro.They consist of four columns carrying a four-squarehorizontal architrave, on which…
