son of Maxentius, forms the vestibule of the present church. It was a
circular building, and fronted towards the Via Sacra. The second
temple Felix made into the nave of the church; it was quadrangular,
and built of brick, but the western wall was of blocks of Gabii stone,
forming part of the second wall of Rome, which was here utilized for
the temple. It is thirty feet in diameter, and was erected in 302 A.D.
Ligorio ("Vatican Codex," 3439) has preserved the inscription:--
IMP . CAES . AUGUSTUS . MAXIMUS . TRIUMPH
PIUS . FELIX . AUGUSTUS.
The two porphyry columns and the cornice belong to the temple; but the
bronze doors are Etruscan, having been sent from Perugia by Urban
VIII. in 1630. The wings on either side of the doorway were added in
772-95 by Hadrian I.; the niches, which still show traces of
frescoing, being for relics of the saints. At the same time the
present flooring of the church was inserted some feet above the
ancient level.
_On the left are slight remains of_