[Illustration: CLAUDIAN AQUEDUCT.]
Sixteen aqueducts supplied the city with water and irrigated the
Campagna. The principal streams were the AQUA APPIA, B.C. 312; ANIO
VETUS, B.C. 272; MARCIA, B.C. 145,--on the top of its arches, near
Rome, were carried the AQUÆ TEPULA and JULIA; VIRGO, B.C. 21; CLAUDIA,
with ANIO NOVUS above, A.D. 38-52. The Romans, finding the water from
the Tiber and the wells sunk in the city unwholesome, built these
aqueducts, to bring the water from the hills that surround the
Campagna; but their situation and purpose rendered them exposed to
attack during war, which partly accounts for their destruction. Four
of them still supply the city with water:--The _Aqua Marcia_, which
has its source near Subiaco. From Tivoli it passes through pipes to
Rome, which it enters at the Porta Pia. It was brought in by a
company, and opened by Pius IX. on the 10th of September 1870. The
_Aqua Virgo_, built by Agrippa, B.C. 21, has its source near the
eighth milestone on the Via Collatina, restored by Nicholas V. It
supplies the Trevi Fountain. The _Aqua Alseatina_, built by Augustus,
A.D. 10, on the other side of the Tiber, has its source thirty-five
miles from Rome, at the Lago Baccano. It was restored by Paul V., and
supplies the Pauline Fountain. _Acqua Felice_, made by Sixtus V., A.D.
1587. Its source is near La Colonna, formerly the source of Hadrian's
Aqueduct. It runs parallel with the Claudian and the Marcian, near
Rome, in some places being built out of their remains and on their
piers. Pliny says: "If any one will diligently estimate the abundance
of water supplied to the public baths, fountains, fish-ponds,
artificial lakes, and galley-fights, to pleasure-gardens, and to
almost every private house in Rome, and then consider the difficulties
that were to be surmounted, and the distance from which these streams
were brought, he will confess that nothing so wonderful as these
aqueducts can be found in the whole world."