The question of the true site of the _Piscina Limaria_, of Frontinus, still remains to be settled, and with it the beginning or source of the great Aqueduct of Claudius, called the _Aqua Claudia_. After carefully examining the bank of the river at a quay at the forty-second ancient mile of the Via Sublacensis, that is to say, between three and four modern miles below Subiaco (which is forty-five miles from Rome), they found the remains of an aqueduct called the _Muraccio_, almost always washed by the water of the river, which enters into it, and then turns at an angle. On entering into the _Muraccio_, Dr. Gori became convinced that it was the Piscina Limaria of Claudius, as described by Frontinus, c. 15, because the water enters freely into the lower chamber, and to the right the _specus_ of the Anio Novus is seen. The water, according to Frontinus, between the entrance from the river and the _specus_ (_inter amnem et specum_), was stopped and purified in the same chamber, before it entered into the conduit. Considering also that between the three lochs, where the water is now pure, and this piscina, there is a considerable distance. In the rainy season the floods bring down a considerable quantity of earth from the neighbouring fields, which makes the water of the Anio Novus muddy; for which reason the Emperor Trajan began, as Frontinus states, to lengthen that aqueduct to the second upper loch, above the Villa Neroniana Sublacensis. Dr. Gori has found that this work of Trajan was completed, by tracing the whole line of it along the left bank of the river Anio. ANOTHER AQUA AUGUSTA. At a meeting of the “Institut de Correspondance Archéologique,” in 1873, the Commendatore G. B. D. Rossi gave an account[215] of another Aqua Augusta, the springs and source of which have been found with that inscription, in the district called _Le Macchie di Rocca di Papa_. This aqueduct appears not to have gone to Rome, but descending into the meadow called the Camp of Hannibal, it went on to the imperial villa at Tusculum, where the magnificent piscina of the time of Trajan or Hadrian is miscalled the House of Cicero. ERRATA ET CORRIGENDA. THE AQUEDUCTS. =Transcriber’s Note:= The errata have not been corrected. Since all notes were reindexed as part of producing this e-text, the note references below have been updated to match the new numbers. _Errata._ _Corrigenda._ _p._ x. Julia (v.) Sources on Mons The Sources are near Grotta Algidus (near Tusculum), Frascati, Ferrata, not Tusculum: and Grotta Ferrata. see p. 42. _p._ x. _col._ 1. (vii.) Lacus Lacus Alsietinus. Alsietina. _col._ 2. Lacus Sabatina. Lacus Sabatinus. At the Cariæ. At the Careiæ. Casale Bianca. Casale Bianco. _p._ xi. _col._ 1. (x.) Lacus Lacus Sabatinus. Sabatina. _col._ 2. (xi.) Torre de’ Scavi. Torre de’ Schiavi.