and Dessau all think was there when the stone was put in the wall, and incline to allow no very remote date for the building of the wall at that point.  To me, after a comparative study of this wall and the one at Norba, the two seem to date from very nearly the same time, and no one now dares attribute great antiquity to the walls of Norba.  But the rest of the cyclopean wall of Praeneste is very ancient, certainly a century, perhaps two or three centuries, older than the part from the Portella down.

There remains still to be discussed the lower wall of the city on the south, and a restraining terrace wall along part of the present Corso Pierluigi.  The stretch of city wall from the Porta del Sole clear across the south front to the Porta di S. Martino is of opus quadratum, with the exception of a stretch of opus incertum[41] below and east of the Barberini gardens, and a small space where the city sewage has destroyed all vestige of a wall.  The restraining wall just mentioned is also of opus quadratum and is to be found along the south side of the Corso, but can be seen only from the winecellars on the terrace below that street.  These walls of opus quadratum were built with a purpose, to be sure, but their entire meaning has not been understood.[42]

The upper wall, the one along the Corso, can not be traced farther than the Piazza Garibaldi, in front of the Cathedral.  It has been a mistake to consider this a high wall.  It was built simply to level up with the Corso terrace, partly to give more space on the terrace, partly to make room for a road which ran across the city here between two gates no longer in existence.  But more especially was it built to be the lower support for a gigantic water reservoir which extends under nearly the whole width of this terrace from about Corso Pierluigi No. 88 almost to the Cathedral.[43] The four sides of this great reservoir are also of opus quadratum laid header and stretcher.

The lower wall, the real town wall, is a wall only in appearance, for it has but one thickness of blocks, set header and stretcher in a mass of solid concrete.[44] This wall makes very clear the impregnability of even the lower part of Praeneste, for the wall not only occupies a good position, but is really a double line of defense.  There are here two walls, one above the other, the upper one nineteen feet back of the lower, thus leaving a terrace of that width.[45] At the east, instead of the lower solid wall of opus quadratum, there is a series of fine tufa arches built to serve as a substructure for something.  It is to be remembered again that between the arches on the east and the solid wall on the west is a stretch of 200 feet of opus incertum, and a space where there is no wall at all.  This lower wall of Praeneste occupies the same line as the ancient wall and escarpment, but the most of what survives was restored in Sulla’s time.  The opus quadratum is exactly the same style as that in the Tabularium in Rome.