It has been mentioned in the account of the Anio Novus (IX.) that, after the main conduit reached the great reservoir at the arch of Dolabella, it was divided into three branches, and that one of these was not completed until the time of Trajan and Hadrian. This important branch was carried over the valley between the Cœlian and the Aventine on a lofty arcade, built upon the _agger_ of Servius Tullius, and over the Aqua Appia, also passing over the Via Appia upon the arch of the Porta Capena to the Piscina Publica. It then ran along the edge of the cliff to the north of S. Balbina, and crossed again the valley between the Pseudo-Aventine and the Aventine itself, a little further to the west, by the side of the road which goes down the hill towards S. Prisca. In the vineyard of S. Prisca a portion of the _specus_ remains perfect, at a very high level[179]. From thence it was carried across the hill to the cliff above the Tiber, where the monastery and garden of S. Sabina are now placed. These are on the site of a palace of the time of the early Empire. Some extensive and important excavations were made there in 1855-57, by the Dominican monks of S. Sabina, and among the discoveries then made were an extensive series of conduits, with a _piscina_ and a _nymphæum_ of the same period,—of the end of the first and the beginning of the second century of the Christian era. A cascade _specus_ served to conduct the surplus water down to the more ancient cave reservoir at the mouth of the Aqua Appia, at the Salaria. An account of these excavations was drawn up by M. Descemet[180], and published in the Memoirs of the Institute of France, with an excellent plan and section. Several brick-stamps, of which the words are given in that work, with the names of the consuls, and some terra cotta water-pipes, with the name of Trajan, were also found here. Others were discovered on the Aventine and near the same spot by Fabretti, who was puzzled by them, because they did not agree with his theories about the aqueducts. Donatus also mentions some of the same facts as known in his time. Some of the bricks were made at the kiln (_figlina_) of Annius Verus, said to have been on the Aventine, near the Salaria; and, if this is correct, that was the spot where they were found. Others have the stamp of Trajan himself. Another is the work of an Arabian servant of Q. Servilius Pudens, A.D. 139, when the Emperor Antoninus Pius and C. Bruttius Præsens were consuls. A piece of leaden pipe, with an inscription upon it, AQVA TRAIANA, was also found on the Aventine. XII. AURELIA, A.D. 185, AND XIII. SEVERIANA, A.D. 190.