Thirteen years after the Julia, the Virgo aqueduct was built. This aqueduct was 14 miles long and is said to be so named because the spring from which it is supplied was first pointed out by a girl to some soldiers who were in search of water. This aqueduct still exists entire, having been partly restored by Nicholas V and the work completed by Pope Pius IV in 1568. [Illustration: Near View of the Claudia Aqueduct] In the tenth year of the Christian era, the Augusta aqueduct was built. This aqueduct was only 6 miles long, and the water that it brought from Lake Aluetimus was of such bad quality as to be scarcely fit for drinking, on which account it is supposed that the founder, Augustus, intended it chiefly for his naumachia. It might be interesting at this point to deviate a little from the history of the Roman aqueducts and draw aside the curtain to catch a glimpse of the aquatic sports or pastimes of a Roman emperor of that period. The naumachia of Augustus was a rectangular basin 1,800 feet long by 1,200 feet wide, in which actual sea fights between rival fleets were held for the amusement of the emperor and his friends. The combatants in these sea fights were usually captives, or criminals condemned to death, who fought as in gladiatorial combats, until one party was killed, unless saved by the clemency of the emperor. The vessels engaged in the sea fight were divided into two parties, called respectively by names of different maritime nations, as Persians and Athenians. The sea fights were conducted on the same magnificent scale and with the same disregard of life as characterized the gladiatorial combats and other public games of the Romans held in the Colosseum. In Nero's naumachia, sea monsters were swimming around in the artificial lake to make short work of any poor unfortunate that was unlucky enough to go overboard. In some of the sea fights exhibited by different emperors, the ships were almost equal in number to real fleets. In one battle there were 19,000 combatants and 50 ships on each side. It was for the purpose then of supplying one of these artificial lakes with water that the Augusta aqueduct was constructed. [Illustration: Aqueduct in Ruins, Ephesus] Perhaps the best known aqueducts of Rome are the Claudia and the Anio Novus. The completion of these waterways, which was accomplished respectively in 50 and 52 A. D., doubled the supply of water to Rome. The Claudia aqueduct was 46 miles in length and the Anio Novus 58 miles in length. The Claudia was commenced by Caligula in the year 38, but was completed, as was the Anio Novus, by the Emperor Claudius. Many other aqueducts besides those mentioned were built at different periods to add to the water supply of Rome. A table is given below showing the date of the constructions and their lengths.