The first sewers of Rome were built between 800 and 735 B. C., and therefore antedate the first aqueduct by between 440 and 487 years. It is evident, therefore, that as originally planned the sewers of Rome were intended to carry off the surface water and in other ways serve to drain the site of the ancient city. Indeed, the Cloaca Maxima, which was constructed during the period of the Kings, from 735 to 510 B. C., was intended to drain the marshy hollow between the Capitoline, Palatine and Esquiline hills, and afterwards, by a process of development, became part of a combined sewage system for the city.
The Cloaca Maxima. From a Recent Photograph
That the engineers who designed the sewerage system of Rome had a clear conception of the service expected of such drains, is evidenced by the manner in which the system was proportioned. The pipes gradually enlarged from their extremities in the buildings through all the ramifications of the system until they finally reached the outlet at a bulkhead or quay-wall in the Tiber. It is stated by early writers that so complete was this system of sewers that every street in the ancient city was drained by a branch into the Tiber.
Egyptian Lady Having Head Sprayed, 1700 B. C.
The Cloaca Maxima was one of the largest and most celebrated of the ancient sewers. The solidity of this structure can be judged by the fact that it has been in uninterrupted service for over 2,400 years, and at the present time is still in use, with no signs of immediate failure. The arches were made of neatly jointed stones fitted together without cement. It is stated by Pliny that a cart loaded with hay could pass down the Cloaca Maxima. It should be borne in mind, however, that a Roman cart and load of hay were of smaller dimensions than a modern one. The actual dimensions of the mouth of the sewer are 11 feet wide by 12 feet high. The lateral branches of the main sewer were of a size in proportion with their requirements and in proportion to the main or trunk sewer. The dimensions of these sewers are evidenced by the service they performed for Nero, who threw into them the unfortunate victims of his nightly riots.