Anio

A´NIO or A´NIEN(the latter form is the more ancient, whence in the oblique cases ANIENIS, ANIENE,&c. are used by all the best writers: but the nominative ANIEN is found only in Cato, ap. Priscian. 6.3. p. 229, and some of the later poets. Stat. Silv. 1.3. 20, 5. 25. Of the Greeks Strabo has Ἀνίων, Dionysius uses Ἀνίης,—ητος). A celebrated river of Latium, and one of the most considerable of the tributaries of the Tiber, now called the Teverone. It rises in the Apennines about 3 miles above the town of Treba ( Trevi) and just below the modern village of Filettino. (Plin. Nat. 3.12. s. 17; Frontin. de Aquaeduct. § 93; Strabo erroneously connects its sources with the Lake Fucinus, 5. p. 235.) From thence it descends rapidly to Subiaco(Sublaqueum), immediately above which it formed in ancient times a small lake or rather a series of lakes, which were probably of artificial construction, as all trace of them has now disappeared. [SUBLAQUEUM] It flows from thence for about 10 miles in a NW. direction, through a deep and narrow valley between lofty mountains, until just below the village of Roviano, where it turns abruptly to the SW. and pursues its course in that direction until it emerges from the mountains at Tibur ( Tivoli), close to which town it forms a celebrated cascade, falling at once through a height of above 80 feet. The present cascade is artificial, the waters of the river having been carried through a tunnel constructed for the purpose in 1834, and that which previously existed was in part also due to the labours of Pope Sixtus V.; but the Anio always formed a striking water-fall at this point, which we find repeatedly mentioned by ancient writers. (Strab. 5. p. 238; Dionys. 5.37; Hor. Carm. 1.7. 13; Stat. Silv. 1.3. 73, 5. 25; Propert. 3.16. 4.) After issuing from the deep glen beneath the town of Tivoli, the Anio loses much of the rapidity and violence which had marked the upper part of its current, and pursues a winding course through the plain of the Campagnatill it joins the Tiber about 3 miles above Rome, close to the site of the ancient Antemnae. During this latter part of its course it was commonly regarded as forming the boundary between Latium and the Sabine territory (Dionys. l. c.), but on this subject there is great discrepancy among ancient authors. From below Tibur to its confluence the Anio was readily navigable, and was much used by the Romans for bringing down timber and other building materials from the mountains, as well as for transporting to the city the building stone from the various quarries on its banks, especially from those near Tibur, which produced the celebrated lapis Tiburtinus, the Travertinoof modern Italians. (Strab. 5. p. 238; Plin. Nat. 3.5. s. 9.)
The Anio receives scarcely any tributaries of importance: the most considerable is the DIGENTIA of Horace ( Ep. 1.18. 104) now called the Licenzawhich joins it near Bardella(Mandela) about 9 miles above Tivoli. Six miles below that town it receives the sulphureous waters of the ALBULAS everal other small streams fall into it during its course through the Campagna, but of none of these have the ancient names been preserved. The waters of the Anio in the upper part of its course are very limpid and pure, for which reason a part of them was in ancient times diverted by aqueducts for the supply of the city of Rome. The first of these, called for distinction sake Anio Vetus, was constructed in B.C. 271 by M‘. Curius Dentatus and Fulvius Flaccus: it branched off about a mile above Tibur, and 20 miles from Rome, but on account of its necessary windings was 43 miles in length. The second, constructed by the emperor Claudius, and known as the Anio Novus, took up the stream at the distance of 42 miles from Rome, and 6 from Sublaqueum: its course was not less than 58, or according to another statement 62 miles in length, and it preserved the highest level of all the numerous aqueducts which supplied the city. (Frontin. de Aquaeduct. § § 6, 13, 15; Nibby, Dintorni, vol. i. pp. 156—160.)
[E.H.B]