CLOACA, klii-a'ka (Lat., sewer). The doom or drains were subterranean passages, usually built of stone, devised to carry off the spring or waste water and the refuse of a Roman city. In Rome the early city was naturally drained by streams running through three valleys between the hills. Three main channels were built to con fine these streams, receive the drainage, and carry it to the Tiber. The largest of these, crossing the Argiletum, Forum, and Velabrum, was called, from its size, the Cloaca Maxima, though that of the Vallis Murcia and that near the Circus Flaminius rival it in size and solidity. A net work of smaller passages empty into these main channels. The system was largely due to the Tar quills. The Cloaca Maxima was built with three large arches, one within the other. The space in closed by the innermost vault was upward of 13 feet in width, and of corresponding height. The arches were built of large blocks of stone, fixed together without cement, of the uniform size of rather more than five feet five inches long and three feet high. The flooring is paved like a Roman road, and the side walls are built of Gahii stone, in blocks measuring sometimes 45 cubic feet. The sewer was kept in a state of
efficiency by a continuous stream of superfluous water from the aqueducts. Large portions of the cloaete remain in some places still visible, but generally buried by the accumulation of soil, at a considerable depth below the present level of the streets. The mouth of the Cloaca Maxima at the Tiber is still visible. During the Republic the surveillance of the Roman cloaca; was one of the duties performed by the censors. The Cloaca Maxima, was repaired by Cato and his colleagues in the censorship. Agrippa. when edile, obtained praise for his exertions in cleans ing and repairing the cloaca, and is recorded to have passed through them in a boat. Under the Empire, officers called curatores eloacurum arbis were appointed for their supervision. So thor oughly was the city undermined by these large sewers that Pliny calls it orbs pensilis, a city suspended in the air rather than resting upon the earth. Drains of the same description, but of smaller dimensions, existed in other ancient Ro man cities.