The
Period of Archaic Rome
The Period of Archaic Rome
II. Aqueducts
For supplying the necessary water for towns, the Romans built a lot of channels and above- ground aqueducts formed of two, sometimes three, rows of overlapped arcades or of high piles joined together by small bolts which supported the water canal (Segonia, Nimes). Frotinus , curator aquarum during the reign of Traian , wrote in one of his works, that Rome received daily a quantity of 790000 cubic meters of water for public fountains, bathrooms, gardens, palaces.
The Romans are considered to be the greatest aqueducts builders. Ancient Rome had eleven major aqueducts, built between 312 B.C. (Aqua Appia) and 226 A.D. (Aqua Alexandrina); the longest (Anio Novus) was 59 miles long. early aqueducts were simply channels bored through the rock, from the water intake in the hills almost to the distribution cistern in Rome. The depth of the channel below ground varied so as to maintain a constant, very shallow gradient (less than 1/200) throughout the length of the aqueduct; vertical shafts were bored at intervals to provide ventilation and access. Only in the final stretches was the conduit raised on arches, to give a sufficient head for distribution of the water within the city.
Roman engineers became more daring in the construction of high arches to
support the conduits across valleys and plains and some of the later
aqueducts were as much as 27 meters (about 100 feet) above ground level
in places. Closed pipes were occasionally used to cross valleys by the
"inverted syphon" method: the pressure forced the water down and up
again on the other side, to a level slightly lower than before. But this
system was costly, as it required lead pipes (lead had to be imported
from Spain or Great Britain) and it was difficult to make joints strong
enough to withstand the pressure; so arches were far more common.
In Athens, under the rule of Pisistratus (B.C. 560), a similarly
extensive, if less difficult, series of works was completed to bring
water from the hills Hymettus, Pentelicus, and Parnes. From Hymettus
were two conduits passing under the bed of the Ilissus, and most part of
the course cut in the rock. Pentelicus, richer in water, supplied
another conduit, which can still be traced from the modern village of
Chalandri by the air shafts built several feet above the ground, and at
a distance apart of 40-50 metres; the diameter of these shafts is 4-5
feet, and the number of them still preserved is about sixty. Tributary
channels conveyed into the main stream the waters of the district
through which it passed. Outside Athens, those two conduits met in a
large reservoir, from which the water distributed by a ramification of
underground channels throughout the city. These latter channels vary in
form, being partly round, partly square, and generally walled with
stone; the chief one, that under the bazaar, is sufficiently high and
broad to allow two men to pass in it. Sometimes pipes of baked clay were
laid within them. The conduit from Mount Parnes [Parnos] appears to have
been reconstructed in later times. Some of these aqueducts continue to
supply Athens to this day, and are described as marvels of enterprise
and skills (E. Curtius, über die Wasserbauten der Hellenen, in the
Archaol. Zeit 1847, p. 19).
In Sicily, the works by which Empedocles, it is said, brought the water into the town of Selinus, are no longer visible; but it is probable that, like those of Syracuse, they consisted chiefly of tunnels and pipes laid under ground. The system of conduits in Syracuse which Thucydides says (vi. 100) the Athenians partly destroyed on the Sicilian expedition, still supplies the town with an abundance of drinkable water; and at one point, where the tunnel passes under the sea to the island of Ortygia, presents what has long been regarded as a remarkable achievement for early times.
An example of what appears to have been the earliest form of aqueduct in Greece has been discovered in the island of Cos [Kos] (Ross, Inselreise, iii. p. 131), beside the fountain Burinna on Mount Oromedon. It consists of a bell-shaped chamber, built underground in the hill side, to receive the water of the spring and keep it cool; a shaft rising from the top of the chamber supplied fresh air. From this reservoir the water was led by a subterranean channel, 35 metres long and 2 metres high.
(1.)
AQUA APPIA
(2.) ANIO VETUS
(3.) AQUA MARITA
(4.) AQUA TEPULA
(5.) AQUA JULIA
(6.) AQUA VIRGO
(7.) AQUA CRABRA or DAMNATA
(8.) AQUA ALSIETINA or AUGUSTA
(9.) AQUA TRAJANA
10.) AQUA ALEXANDRINA
(11.) AQUA SEPTIMIANA
