AQUEDUCT

, or Aquæduct, as much as to say ductus aquæ, a conduit of water, is a construction of | stone or timber built on uneven ground, to preserve the level of water, and convey it, by a canal, from one place to another.—Some aqueducts are under ground, being conducted through hills, &c; and others are raised above ground, and supported on arches, to conduct the water over vallies, &c.

The Romans were very magnificent in their aqueducts; having some that extended a hundred miles, or more. Frontinus, a man of consular dignity, who had the direction of the aqueducts under the emperor Nerva, speaks of nine that emptied themselves through 13594 pipes, of an inch diameter. And it is observed by Vigenere, that in the space of 24 hours, Rome received from these aqueducts not less than 500000 hogsheads of water. The chief aqueducts now in being, are these: 1st, that of the Aqua Virginia, repaired by pope Paul IV; 2d, the Aqua Felice, conitructed by pope Sixtus V, and is called from the name he assumed before he was exalted to the papal throne; 3d, the Aqua Paulina, repaired by pope Paul V, in the year 1611; and 4thly, the aqueduct built by Lewis XIV, near Maintenon, to convey the river Bure to Versailles, which is perhaps the largest in the world; being 7000 fathoms long, elevated 2560 fathoms in height, and containing 242 arcades. See Philos. Trans. for 1685, No. 171; or Abridg. vol. 1. pa. 594.