originally made by Tarquinius Superbus in the year 138 of Rome, or 530
years before Christ: part of the actual construction appears to be
original and of that time. It is built of the larger blocks of tufa,
and has a round-headed vault. The German theory is, that this great
drain was originally open at the top, and not vaulted over till the
time of Camillus, after the capture of Veii in the war with the
Etruscans; but the construction does not agree with this. The
additional branch of the Cloaca made by Agrippa to carry off the water
from his thermæ near the Pantheon (to supply which the Aqua Virgo was
made), is of brick, after the fashion of his time. This can be seen at
the junction near the Church of S. Giorgio in Velabro or the Janus
Quadrifrons. Several natural streams of water are collected in this
great drain, and still run through it. One, from the Quirinal, runs
straight between the Palatine and the Capitol; a second comes from the
eastern side of the Palatine and the Arch of Titus; a third runs from
the Capitol, the spring being in the lower chamber of the Prison of S.
Peter. All these met near the Forum Romanum, and formed the Lake of
Curtius, which was drained by the great Cloaca. But this drain is not
so low down as the lake is deep; consequently there is always a swamp
there, even now, after much rain. Two other streams fall into it near
the Janus,--one from the direction of the Pantheon; the other from the
western side of the Palatine, coming out of the cave called the
Lupercal, where the water gushes out from under the arch with great
force. This is called the Aqua Argentina, or the Silvery Water, either
from its beautiful clearness, or because it went through the
silversmiths' quarter.
_Regaining the_ VIA S. TEODORO, _turn left, under the Palatine. On the
right is the_