Note 169 — Chapter III · ROMAN ARCHITECTURE.

When the first edition of this work was written I believed the rotunda to have been added to the portico by Severus; and if this were so it would get over many of the difficulties arising from its size and the character of its brickwork. My personal examination, however, has forced me very unwillingly to give up this hypothesis. It certainly is, however, very astonishing that such a vault should have been attempted at so early an age.

[There seems to be some probability that Mr. Fergusson’s first belief was correct, and that the Rotunda was built by Hadrian, bricks with the stamp of his period having been found in the casing and in the bond courses in the solid concrete both of the drum and in the dome. The discovery is due to M. Chedanne, one of the “Grand Prix” students in the Villa Medici, who had selected the subject for his “Envoi de Rome,” and was allowed to superintend certain repairs and restorations which were required in the Pantheon. It would seem that the portico erected by Agrippa preceded a temple with cella of the ordinary form, the pavement of which has been found nearly seven feet below the floor of the present church. From this it follows that when the Rotunda was erected in the first half of the second century, the portico, which is undoubtedly of Agrippa’s time, must have been taken down and rebuilt on to it, and this explains Mr. Fergusson’s reasons for insisting that the portico was built on to the Rotunda. The theory as to the Pantheon forming part of Agrippa’s bath is thus disposed of. Independently of that, however, Prof. Middleton has pointed out that the discoveries made in 1882, by the removal of the block of houses at the back, showed that there was no connection whatever between the two buildings. Traces exist of the original marble lining, and of cornices which were continued round the dome, showing that originally the complete circuit was exposed to view. “Moreover,” Prof. Middleton states, “if further proof were wanting to contradict the theory that the Pantheon was over the Calidarum or Laconicum of the bath, this is supplied by the fact that there is no trace of any hypocaust under the floor, but merely an ancient drain to carry away the rain-water that fell through the opening in the dome. The Pantheon, too, is on the north side of the Thermæ—a very improbable position for the Laconicum, or hot room, which was usually placed on the sunny side of the buildings.”—Ed.]