Back: The only ancient Roman edifice at Rome in perfect preservation in which walls and vaulting are original. The foundation of bldg. dates from Augustus in 27 B.C. Struck by lightning in reign of Trajan and restored by Hadrian. Portico only part unaltered by this restoration. The entire circular portion including dome from Hardrian [sic] period. Another restoration happened under Septimus Severus and Caracalla. After expiry of Pagan worship was unoccupied until presented by Phocas to Pope Boniface IV consecrated as Christian Church in 609. Emperor Constans. II removed the bronze-gilt tiles of roof to Constantinople in 662. In 731-41 Gregory III covered dome with lead. Since then has been frequently restored. Portico 36 yds. wide and 14 yds. deep. to which 5 steps originally ascended now covered by raising of grades. The cols. [columns] of unpolished pink and some grey green granite with white marble caps. Entablature and all other fragments of white marble now almost black. Original bldg. covered with white marble slabs. Cols. 14 1/2 ft. circ. 41 ft. high. Tympanum originally contained reliefs. Colonnades of portico originally vaulted over. In 1632 Pope Urban VIII (Barberini) removed the brazen tubes on which the dome rested converting them into the cols. for canopy of high altar of St. Peters. Bronze entrance doors original antique. Inscription on frieze rotten modern work.
