Quitting the in-door life of the Roman, let us turn our attention to other monuments of labor and art, which are no less remarkable. Foremost among these stand the sewers and aqueducts of Rome. So thoroughly was the drainage of the city provided for, that the ground was tunneled through and through with arched passages; and Pliny’s expression, “the hanging city,” is literally correct. The most important of the sewers was built under the rule of the elder Tarquin, and planned in a spirit prophetic of future greatness. It is composed of three concentric arches, forming a channel of fourteen feet in diameter, and proportional height. This was the main trunk, into which was discharged the drainage flowing through a multitude of subterranean channels, together with the vast surplus quantity of water from the aqueducts used to cleanse the net-work of drains. A cart loaded with hay could be driven down the main passages, and Agrippa is said to have performed a sanitary voyage in a boat through the main sewers, when superintending their repair. More attractive, though not more useful, monuments of labor and care for the public health, remain in the aqueducts, by which a plentiful supply of water was always insured to the city of the seven hills--the mere dilapidated remains of which still suffice for her present use. A mere glance at the proportions of some of these noble works, which conveyed the purifying and health-giving element, through hills and across valleys, from sources varying in distance from sixty miles downward, may well raise a blush at the scant and meagre substitutes which we can show in the nineteenth century. Well may Frontinus, in an exulting tone, compare the useful splendor of the nine aqueducts, which in his time supplied the city, with the useless, slave-grown bulk of the pyramids, or the merely decorative works of Grecian towns.