ĂQUAE DUCTUS

( ὑδραγωγία ), literally, a water-conduit, but the word is used especially for the magnificent structures by means of which Rome and other cities of the Roman empire were supplied with water. A Roman aqueduct, often called simply aqua , may be described in general terms as a channel, constructed as nearly as po ible with a regular declivity from the source whence the water was derived to the place where it was delivered, carried through hills by means of tunnels, and over valleys upon a substruction of solid masonry or arches. The aqueduct is mentioned by Strabo as among the structures which were neglected by the Greeks, and first brought into use by the Romans. Springs ( κρῆναι , κρουνοί ) were sufficiently abundant in Greece to supply the great cities with water; and they were frequently converted into public fountains by the formation of a head for their waters, and the erection of an ornamental superstructure. Of this we have an example in the Enneacrunos at Athens, which was constructed by Peisistratus and his sons. The Romans were in a very different position, with respect to the supply of water, from most of the Greek cities. They, at first, had recourse to the Tiber, and to wells sunk in the city; but the water obtained from those sources was very unwholesome, and must soon have proved insufficient, from the growth of the population. It was this nece ity that led to the invention of aqueducts, in order to bring pure water from the hills which surround the Campagna. The number of aqueducts was gradually increased, partly at the public expense, and partly by the munificence of individuals, till, in the fourth century of the Christian era, they amounted to fourteen. Of these only four belong to the time of the republic, while five were built in the reigns of August us and Claudius.—1. The Aqua Appia , begun by the censor Appius Claudius Caecus in B.C. 313. Its sources were near the Via Praenestina , between the seventh and eighth mile-stones.—2. The Anio Vetus was commenced forty years later, B.C. 273, by the censor M. Curius Dentatus, and was finished by M. Fulvius Flaccus. The water was derived from the river Anio, above Tibur, at a distance of 20 Roman miles from the city; but, on account of its windings, its actual length was 43 miles.—3. The Aqua Marcia , one of the most important of the whole, was built by the praetor Q. Marcius Rex, by command of the senate, in B.C. 144. It commenced at the side of the Via Valeria , 36 miles from Rome.—4. The Aqua Tepula , built by the censors Cn. Servilius Caepio and L. Ca ius Long in us in B.C. 127, began at a spot in the Lucullan or Tusculan land, two miles to the right of the tenth milestone on the Via Latina . It was afterwards connected with.—5. The Aqua Julia , built by Agrippa in his aedileship, B.C. 33. It was conducted from a source two miles to the right of the twelfth milestone on the Via Latina , first to the Aqua Tepula , in which it was merged as far as the reservoir ( piscina ) on the Via Latina , seven miles from Rome. From this reservoir the water was carried along two distinct channels, on the same substructions; the lower channel being called the Aqua Tepula , and the upper the Aqua Julia ; and this double aqueduct again was united with the Aqua Marcia , over the watercourse of which the other two were carried.—6. The Aqua Virgo , built by Agrippa, to supply his baths. From a source in a marshy spot by the 8th milestone on the Via Coll at in a , it was conducted by a very circuitous route.—7. The Aqua Alsietina (sometimes called also Aqua August a ), on the other side of the Tiber, was constructed by August us from the Lacus Alsietinus ( Lago di Martignano ), which lay 6500 pa us to the right of the 14th milestone on the Via Claudia .—8, 9. The two most magnificent aqueducts were the Aqua Claudia and the Anio Novus (or Aqua Aniena Nova ), both commenced by Caligula in A.D. 36, and finished by Claudius in A.D. 50. The water of the Aqua Claudia was derived from two copious and excellent springs, near the 38th milestone on the Via Sublacensis . Its length was nearly 46½ miles. The Anio Novus began at the 42nd milestone. It was the longest and the highest of all the aqueducts, its length being nearly 59 miles, and some of its arches 109 feet high. In the neighbourhood of the city these two aqueducts were united, forming two channels on the same arches, the Claudia below and the Anio Novus above. These nine aqueducts were all that existed in the time of Front in us, who was the curator of the aqueducts in the reigns of Nerva and Trajan. There was also another aqueduct, not reckoned with the nine, because its waters were no longer brought all the way to Rome, viz.: 10. The Aqua Crabra .—The following were of later construction. 11. The Aqua Trajana , brought by Trajan from the Lacus Sab at in us (now Braccia no ).—12. The Aqua Alex and rin a , constructed by Alexander Severus; its source was in the lands of Tusculum, about 14 miles from Rome.—13. The Aqua Sep tim i an a , built by Septimius Severus, was perhaps only a branch of the Aqua Julia .—14. The Aqua Algentia had its source at M. Algidus by the Via Tusculana . Its builder is unknown.—Great pains were taken by succe ive emperors to preserve and repair the aqueducts. From the Gothic wars downwards, they have for the most part shared the fate of the other great Roman works of architecture; their situation and purpose rendering them peculiarly exposed to injury in war; but still their remains form the most striking features of the Campagna, over which their lines of ruined arches, clothed with ivy and the wild fig-tree, radiate in various directions. IMG:6459379820872971714_ill030.jpg: Triple Aqueduct. Three of them still serve for their ancient use. They are—(1.) The Acqua Vergine , the ancient Aqua Virgo . (2.) The Acqua Felice , named after the conventual name of its restorer Sixtus V. (Fra Felice), is, probably, a part of the ancient Aqua Claudia , though some take it for the Alex and rin a . (3.) The Acqua Paola , the ancient Alsietina .—The following woodcut represents a restored section of the triple aqueduct of Agrippa:— a. the Aqua Marcia ; b. the Aqua Tepula ; c. the Aqua Julia . The two latter are of brick and vaulted over. The air-vents are also shown.—The channel of an aqueduct ( spec us , canal is ) was a trough of brick or stone, lined with cement, and covered with a coping, which was almost always arched; and the water either ran directly through this trough, or it was carried through pipes laid along the trough. These pipes were of lead, or terra-cotta ( fictiles ), and sometimes, for the sake of economy, of leather. At convenient points on the course of the aqueduct, and especially near the middle and end, there was generally a reservoir ( piscina , piscina limos a ) in which the water might deposit any sediment that it contained. The water was received, when it reached the walls of the city, in a vast reservoir called castellum , which formed the head of water and also served the purpose of a meter . From this principal castellum the water flowed into other castella , whence it was distributed for public and private use. The term castellum is sometimes also applied to the intermediate reservoirs already mentioned. During the republic, the censors and aediles had the superintendence of the aqueducts. August us first established curatores (or praefect i ) aquarum , who were invested with considerable authority. They were attended outside the city by two lictors, three public slaves, a secretary, and other attendants. In the time of Nerva and Trajan, 460 slaves were constantly employed under the orders of the curatores aquarum in attending to the aqueducts. They consisted of:—1. The villici , whose duty it was to attend to the pipes and calices . 2. The cas tellar i i , who had the superintendence of all the castella , both within and without the city. 3. The circuit ores , so called because they had to go from post to post, to examine into the state of the works, and also to keep watch over the labourers employed upon them. 4. The silicarii , or paviours. 5. The tectores , or masons. These and other workmen appear to have been included under the general term of Aquarii .