THE APPIA (I.) at the PORTA CAPENA, in the eastern tower of the gate, now in the house of the gardener of the monks of S. Gregory. The _specus_ is built of large blocks of tufa, and the lower part of it cut in the tufa wall of Servius Tullius; it was distinctly visible in the excavations of 1870, when this drawing was made. The line of the aqueduct upon the short _agger_ between the Cœlian and the Aventine was also visible for several yards, and in three different places, where pits were dug fifteen feet deep, the last was where a branch was carried into the Piscina Publica. The middle pit was in waste land on the western side of the present south road through the gate of S. Sebastian, or the modern line of the Porta Appia. It was to this pit that his holiness Pius IX. was taken to see it by the Cavaliere Guidi, and he said there was no denying that this was part of the wall of Servius Tullius, but he was surprised that his Roman friends had not discovered this. The greater part of the pits that he opened might have been left open, if it had not been for the prejudices of the subordinate officers of the Government. The particular pit in question was in waste ground by the side of the road, and might have been left open without any inconvenience. PLATE III. [Illustration: III. AQUEDUCTS—AQUA APPIA, SPECUS. IN A STONE QUARRY UNDER S. SABBA, ON THE AVENTINE, WHERE SEVEN BRANCHES OF LATER AQUEDUCTS CAST THEIR SURPLUS WATER INTO THE APPIA, EXCAVATED IN 1868.] The Appia (I.) under S. Sabba, in an old subterranean stone quarry. Several branches of other and later aqueducts here cast their surplus water into the _specus_ of the Appia, the earliest and the lowest (as shewn in the plan). The _specus_ is also visible in several places, filled up to one-third of its depth by the deposit of clay left by the water, which comes from swampy meadows on the bank of the river Anio, in which the soil is clay, upon tufa rock, called the “Meadows of Lucullus.”