[75] Ibid.
[76] Frontinus, c. 19.
[77] ‘The three aqueducts’ in this passage may mean either the Anio Vetus, the Marcia, and the Claudia, all of which come from the neighbourhood of Subiaco, and follow the same line on the bank of the river Anio, and the cliffs above it as far as Tivoli, but diverge considerably between Tivoli and the Piscinæ; or it may mean that the Tepula and the Julia coming from near Marino, and the Marcia coming from Tivoli, meet at this point—both are true. The piscinæ of the Claudia, the Anio Novus, the Marcia, the Tepula, the Julia, are all within half-a-mile of each other.
[78] Dr. F. Gori says that the lake of S. Lucia, in the territory of Arsoli, near Subiaco, is not the source of the Aqua Marcia, but of the Aqua Claudia only, and that the sources of the Aqua Marcia are nearer to Subiaco, and are called by the people Acque Serene. He also considers that the branch of the Aqua Augusta added to the Marcian by Augustus, now called Le Rosoline, comes from near the village of Agosta, and that the spring, now called La Fonte (Fons novus Antoninianus), added to the Marcian by Antoninus Caracalla, is under the same village of Agosta. One of the inscriptions on the Porta S. Lorenzo records this. See Delle varie Sorgenti dell’ Acqua Marcia, &c., pp. 56, 57.
[79] The new company had at first proposed to draw their chief supply of water from the small lake called the Lago di S. Lucia, which is nearer to Rome, and which they had been misinformed was the Aqua Marcia. Dr. Fabio Gori, from his great local knowledge and his archæological researches, was able to shew that this was a mistake, and wrote to that effect a letter in the Roman newspaper called the Osservatore Romano. This letter at first gave great offence, and a very warm controversy was carried on for some time on that subject. Eventually, however, a new engineer of the company thought it better to examine the ground himself, and the result was to establish that Gori’s views were perfectly correct. He then became a warm advocate for the company, which he thinks entitled to great praise for the admirable manner in which its works in the valley of the Anio have been carried out as far as Tivoli. Their works almost equal those of the time of the Empire, and are carried out on the same principles; but from Tivoli to Rome the water is carried in metal pipes, and not in a stone specus as it is above Tivoli. This enables the company to carry it in a more direct line.
[80] See the Appendix to this Section.
[81] A great deal too much importance has been attached to this Cyclopean Masonry, Opus Cyclopæum. See the Chapter on the Construction of Walls.
[82] It is probably the case that part of this supply was brought in metal pipes only, from the evidence of this inscription. A stone specus passes under the wall on the bank round three sides of the camp on the exterior of the walls, and is plainly visible at the north-east corner; but this agrees with the general character of the Anio Vetus, and was probably a branch from that aqueduct.
The inscription is as follows:—
IMP. CAES. M. OPELLI . SEVERI . MACRINI
. AVG
M. OPELLI . SEVERI . DIADVMENIANI .
CAES. PRINC. IV
CASTRIS . PRAETORI
TERENTIVS . CASSANDER . FECIT