CLOA´CA
CLOA´CA (
ὑπόνομος), a
drain. The removal of the sewage of cities by an extensive system of drains
is as old as the Assyrian civilisation, for we find it carried out at
Nineveh with great completeness, the brick vaulting assuming all the known
forms of the arch, while the pavement is formed of flagstones. (Layard,
Nineveh and Babylon, p. 54; Place,
Ninive et
l'Assyrie, p. 269.)
As a specimen of the drainage of a Greek city, we may quote that of Athens,
the remains of which are described by E. Ziller (
Mittheil. des
deutsch. Inst. in Athen, 1877, pp. 117-119), who has traced it
from the Kolokotroni street (though he thinks that it may have started
nearer the old wall on the east side of the city) to the church of
Kapnikarea, and thence in a northwesterly direction on the west side of
Hermes street to the Dipylon. Air-shafts, about 6 metres in depth, at
various points permit an investigation of the construction, in which at some
places dressed Piraeus stone, at others brick, is used. Outside the Dipylon
the drain enters a reservoir, from the sides of which small square or
cylindrical canals lined with brick carried the contents towards the plain
and the olive woods, thus apparently pointing to an ancient system of
applying the refuse of a city to fertilise sewage farms. One of these canals
appears to show traces of a contrivance for regulating the amount of sewage
supplied, which leads Ziller to the conjecture that the sewage supply was
let out to the farmers.
The admiration with which the
cloacae of Rome
were regarded by antiquity may be judged from the passage of Dionysius of
Halicarnassus (3.67), in which he classes them with the aqueducts and the
roads as the most magnificent works in Rome, and the best proof of the
greatness of the empire. (Cf.
Plin. Nat. 36.
§§ 104-8; and Cassiodorus,
Var. 3.30,
“videas illic fluvios quasi montibus concavis clausos.” )
Remains of a system of
cloacae have been found
in so many of the Roman cities of North Italy and France that they may
indeed be considered a mark of Roman civilisation, as characteristic as the
aquaeductus and the
via.
The chief of the ancient drains still existing in Rome is the famous
Cloaca Maxima, which starts in the valley of the
Subura at the foot of the Carinae, crosses the Forum under the S. end of the
Basilica Julia, where it is exposed to view, thence under the Vicus Tuscus
and the Velabrum, and after being again visible near the arch of Janus
Quadrifrons, as is shown in the accompanying illustration, it enters the
Tiber near the Temple of Hercules in the Forum Boarium, by an arch of
lapis Gabinus or peperino, formed of three
rings of voussoirs. We give an illustration showing this arch, surrounded by
the more weathered tufa of the
Pulchrum Littus
or ancient quay wall. Its original dimensions were 12 ft. 4 in. in height
and 10 ft. 8 in. in width, but one-third of its height is now choked up by
mud.
[p. 1.462]This triple peperino arch extends for about
40 ft. from the mouth; but in the rest of its course the drain is vaulted
with a single arch of tufa
 |
Cloaca Maxima.
|
voussoirs 2 ft. 2 in deep, with occasional bands of travertine.
The masonry of the peperino arch especially is fine and of ancient
character.
 |
Present condition of the Cloaca Maxima.
|
This drain was no doubt constructed to carry off not only the sewage, but
also the surface water from the surrounding slopes, which made the low
ground traversed by the drain a swamp. Hence the early construction of this
great work, which is attributed to Tarquinius Priscus by Dionys. and Pliny
(
ll. cc.), while Livy divides the honour between
Tarquinius Priscus and Tarquinius Superbus (1.38, 56). Mommsen, however,
thinks that while the scheme of drainage was instituted under the kings,
this vaulted cloaca must belong to the republican period, erroneously
stating that the vault is throughout of travertine, a stone characteristic
of post-regal times, and holding that the arch was unknown even to the
Greeks until the end of the fifth century before Christ (
Hist. of
Rome, 1.117, 490, Eng. trans. ; Seneca,
Ep.
90.32). But in support of the earlier date, which is now generally assigned
to the Cloaca Maxima, we may quote Etruscan instances, which are probably at
least as early: for instance, the mouth of an ancient
cloaca discovered at Graviscae by Dennis (
Cities of
Etruria, 1.433), consisting of an arch of 14 ft. span formed of
voussoirs of uncemented tufa 5 ft. deep, and opening in a quay wall about 20
feet high.
Another
cloaca running from the corner of the
Via Paganica and the Piazza Mattei, under the Ghetto, enters the Tiber
opposite to the Insula Tiberina. It is constructed of large uncemented
blocks of peperino: this and other indications would assign it to the regal
period. Like the Cloaca Maxima, it is still in use, having been connected
with the drain
dell' Olmo in 1600 (Narducci,
Boll.
dell' Inst. 1881, p. 209). These drains of the regal period
probably follow the old lines of the streets, as they ran before the
destruction of Rome by the Gauls.
In the quay wall not far from the mouth of the Cloaca Maxima may be seen two
smaller arched openings, one of which is now dry; the other discharges the
waters of the Aqua Crabra. These may be terminations of the
cloacae of the Aventine, which were not constructed
until the year 184 B.C., when M. Porcius Cato and
L. Valerius Flaccus constructed new drains and repaired the existing ones.
To this occasion possibly may be referred the statement of the contemporary
C. Acilius, quoted by Dionys. (
l.c.), that the mere
repair of the drains cost 1000 talents. M. Agrippa, during his aedileship in
36 B.C., showed great zeal in the supervision of
the
cloacae, traversing them in a boat and
cleansing them at his own expense (Plin.
l.c.;
D. C. 49.43), and constructed a
cloaca to drain the Campus Martius, which was
connected with the Thermae of Agrippa and the Aqua Virgo. This was
discovered under Urban VIII., and is at present in use under the name of the
Chiavica della Rotonda.
The discoveries made at various times show that the network of smaller drains
communicating with these main
cloacae still
exists, though in great part choked up. Brick is largely used in their
construction; sometimes they are covered in with a barrel vault, sometimes
by two tiles leaning against each other, sometimes by a single flagstone,
but in some cases we find the primitive arrangement of projecting courses of
stone which was observed above in the drains of Athens.
The expense of cleansing and repairing these
cloacae was, of course, very great, and was defrayed partly by
the treasury, and partly by an assessment called
cloacarium. (
Dig. 7,
1,
27.3; 30, 1, 39.5; Marquardt,
Röm. Staatsv. ii. p. 146.) Under the republic,
the administration of the sewers was entrusted to the censors and aediles;
but under the empire, particular officers were appointed for that purpose,
cloacarum curatores, mention of whom is
found in inscriptions (ap. Grut. p. 197.5, p. 198.2-5; p. cclii. 1, 2).
Under the empire condemned criminals were employed in cleansing the
cloacae. (
Plin. Ep.
10.44 (41).) Theodoric appointed an official to repair the drains, a
striking instance of the esteem in which the barbarians held Roman
civilisation (Cassiod.
l.c.).
On the legal obligations relating to the
cloacae
at Rome, see Schmidt,
Interdicta de cloacis, in
Zeitschrift f. gesch. Rechtswiss. 15.1, pp. 51
seq. For further details as to the Roman
cloacae, see Burn,
Rome and the
Campagna; and Middleton,
Rome in 1885.
Some traces of the drainage of Pompeii were discovered by Mazois
(
Ruines de Pompéi, 1.53; 2.36, 99). The
extensive remains of the Roman
cloacae of
Nicomedia are described by Perrot and others,
Exploration Arch. de
Galatie et Bithynie, 1.2; and by Texier,
Descript. de
l'Asie Mingure, i. p. 24.
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