AQUEDUCT

(Lat. aqua, water, and duct us, a conduit.) A conduit or channel for conveying water from one place to another; more particularly applied to structures erected for the purpose of conveying the water of distant springs acro valleys, for the supply of large cities. The largest and most magnificent aqueducts, with the existence of which we are acquainted, were the work of the Romans; and the ruins of several of them, both in Italy and other countries of Europe, remain to the present time monuments of the power and industry of that enterprising people. The aqueduct of Appius Claudius was the most ancient, and constructed in the 442d year of Rome. It conveyed the Aqua Appia to the city, from a distance of between 7 and 8 miles, by a deep subterranean channel of more than 11 miles in length. The aqueduct of Quintus Martins was a more extraordinary structure. It commenced at a spring 33 miles distant from Rome, made a circuit of three miles, and afterwards, forming a vault of 16 feet diameter, it ran 38 miles, along a series of arcades at an elevation of 70 English feet. It was formed of three distinct channels, placed one above the other, conveying water from three different sources. In the uppermost flowed the Aqua Julia; in the second, the Aqua Tepula; and in the undermost, the Aqua Martia. The Aqua Virginia, constructed by Agrippa, pa ed through a tunnel of 800 paces in length. The Aqua Claudia, begun by Nero and finished by Claudius, conveyed the water from a distance of 38 miles. This aqueduct formed a subterraneous stream of 30 miles in length, and was supported on arcades through the extent of 7 miles; and such was the solidity of its construction that it continues to supply the modern city with water to the present day. The waters of the river Anio were also conducted to Rome by two different channels; the first was carried through an extent of 43 miles, and the latter through upwards of 63 miles, of which 6| miles formed one continued series of arches, many of them upwards of 100 feet in height. Nine great aqueducts existed at Rome at the commencement of the reign of Nerva. Five others were constructed by that emperor, under the superintendence of Julius t ront in us; and it appears that at a later period the number amounted to twenty. The supply of water fui-nished by these different works was enormous. " According to the enumeration of Front in us, the nine earlier aqueducts delivered every day 14,018 quinaria. This corresponds to 27,743,100 cubic feet. We may therefore extend the supply, when all the aqueducts were in action, to the enormous quantity of 50,000,000 cubic feet of water. Reckoning the poF 3 [s. 82]