showed above ground; it is no doubt the "Tropæum" alluded to by the Presbyter Caius, circa A.D. 210.
Roughly, the height of the two chambers from the floor of the original vault to the ceiling of the Memoria built over it is some 32 feet. There is little difference in the height of each of these two chambers.
The probable explanation of the details given in the Liber Pontificalis of the works of Constantine the Great at the tomb is as follows: Both the chambers of the tomb—the original vault and the Memoria of Anacletus over it—were left intact, but with certain added features, simply devised with the view of strengthening and ensuring the permanence of the sacred spot and its contents. The whole of the chamber of the tomb was then filled up with solid masonry, except immediately above the sarcophagus.
The upper chamber, the Memoria, was strengthened with masses of masonry on each side, so as to bear the weight of a great altar, the high altar of the Basilica of Constantine, which was erected so as to stand immediately over the body of S. Peter. A cataract or billicum, as it is sometimes called, covered with a bronze grating, opened from above close to the altar. There are two of these little openings, one leading into the Memoria, and the other from the Memoria to the chamber of the tomb beneath. Through these openings handkerchiefs and such-like objects would be lowered so as to touch the sarcophagus. This we know was not unfrequently permitted in the fifth, sixth, seventh, and eighth centuries. Such objects after they had touched the coffin were esteemed as most precious relics.
In addition to these works in the two chambers, the Emperor Constantine enclosed the original stone coffin which contained the remains of S. Peter in bronze, and laid upon this bronze sarcophagus the great cross of gold—the gift of his mother Helena and himself. This is the cross which Pope Clement VIII and his cardinals saw dimly gleaming below, when an opening to the tomb was suddenly disclosed in the great building operations which were carried out during the last years of the sixteenth century.
There is scarcely room now for doubt that the bronze
