John Lord, Beacon Lights of History, Volume 3 part 1…
“ The nave is divided into five aisles, and the main one, opening into the apsis, is spanned by a lofty arch supported by two colossal columns. The apsis is eighty feet in breadth. All parts of the church—one of the largest of Rome— are decorated with mosaics. It has two small transepts at the extremity of the nave, on each side of the apsis. The four rows of magnificent columns, supporting semicircular arches, are Corinthian. In this church the Greek and Roman architecture predominates. ”
