tractors, every day I visited the excavations which were still in
progress, on each side of the Corso, for building the Cavalletti and
Bassi palaces, and lastly, I examined the "column with foliage carved
upon its surface," which in the mean time had been removed to the
courtyard of the Palazzo dei Conservatori on the Capitol. This marble
fragment, the only one saved from the excavations, gave me the clue to
the mystery. It was not a column, it was a _pulvinus_, or volute, of a
colossal marble altar, worthy of being compared, in size and
perfection of work, with the Altar of Peace discovered under the
Palazzo Fiano, with that of the Antonines discovered under the Monte
Citorio, and with other such monumental structures. There was then no
hesitation in determining the nature of the discoveries made in the
Corso Vittorio Emanuele; an altar had been found there, and this altar
must have been the one sacred to Dis and Proserpina, as no other is
mentioned in history in the northwest section of the Campus Martius.

The drawings which illustrate my account of the discovery[45] prove
that the altar rose from a platform twelve feet square, approached on
all sides by three or four marble steps, that platform and altar were
enclosed by three lines of wall at an interval of thirty-six feet from
one another, and that on the east side of the square ran a _euripus_,
or channel, eleven feet wide, and four feet deep, lined with stone
blocks, the incline of which towards the Tiber is about 1:100. This
last detail proves that when the rough altar of Volesus Sabinus was
succeeded by the later noble structure, the pool was drained, and its
feeding springs were led into the _euripus_, so that the patients
seeking a cure for their ailments could bathe in or drink the
miracle-working waters with greater ease. No attention whatever was
paid to the discovery at the time it took place. Instead of reaching
the ancient level, the excavation for the main sewer of the Corso
Vittorio Emanuele was stopped at the wrong place, within three feet of
the pavement; consequently whatever fragments of the altar, of
inscriptions, or of works of art, were lying on the marble floor will
lie there forever, as the building of the palaces on either side of
the Corso, and the construction of the Corso itself, with its costly
sewers, sidewalks, etc., have made further research impossible, at
least with our present means.

Concerning the celebration which took place a