This piece of _terra-cotta_ is of the first century of the Roman Empire; but _at what period_ the name and address of the cobbler was scratched upon it, is a question not so easily answered. [55] The Aqua Claudia and Anio Novus enter Rome at the extreme eastern point on a lofty arcade, which formed the northern boundary of the Sessorian gardens, and was incorporated in the Wall of Aurelian. This extends for about a quarter of a mile; it then turns at a sharp angle to the north, and passes over the Porta Maggiore, to its final reservoir in a tower at an angle to the north of that gate. But part of the water of the Claudia and the Anio Novus united, was carried straight on along the bank on which the arches of Nero stand, to the Cœlian Hill and the reservoirs at the west end of it. The temple, called by Canina _Spes_, stood near the angle where the water was divided into two distinct channels, between that point and the Porta Maggiore. [56] The name of _Porta Esquilina_ is here given to the Porta Maggiore, the outer gate on the road to the Esquiline. The same name was also given to the inner gate in the _agger_ of Servius Tullius; but there must always have been an outer gate also in the outer _mœnia_, or bank and wall for enclosure, which was a necessary part of every fortified city. (The same name, _Porta Angelica_, is still given to both the inner and the outer gate of the Leonine City, near the Vatican.) The high streams were carried on this bank to the Porta Viminalis of Frontinus, now called the _Porta di S. Lorenzo_. The remains of these three aqueducts can be plainly seen on entering through the city wall close to the Porta Maggiore, on the north side, and going along on this bank to the Porta di S. Lorenzo. The _specus_ is visible at both ends, carried on arches. In the middle the ground is higher, and the _specus_ pass through it underground, and then emerge and are carried again upon arches, exactly as described by Frontinus. The Aqua Felice is carried _over_ the three aqueducts of the Marcian arcade; it is on arches twenty feet from the ground at each end, and in the middle, where these three are underground. The lower part of the _specus_ of the Aqua Felice almost touches the ground, while the other three are underground. [57] The _gemelli_ are, in all probability, the large twin reservoirs just outside the western wall of the Sessorium, now in a large vineyard near the Porta Maggiore, through which the Neronian arches pass. These reservoirs are below the level of the _specus_ of the Anio Vetus, as was shewn by some excavations made in them under my direction in 1869. [58] Some of the water had been thrown into the old _specus_ at the junction of the Claudian with the Neronian arches.