ine, near the church of St. Saba. The galleries of
this quarry, much disfigured by medieval and modern use, can be followed
to a considerable distance, altho the collapsing of the vaults makes it
dangerous to visit them....

The quarries of the third quality were, or rather one of them was,
discovered on February 7, 1872, in the Vigna Querini, outside the Porta
St. Lorenzo, near the first milestone of the Vicolo di Valle Cupa. It
was a surface quarry, comprising five trenches 16 feet wide, 9 feet
deep. Some of the blocks, already squared, were lying on the floor of
the trenches, others were detached on two or three sides only, the size
of others was simply traced on the rock by vertical or horizontal lines.
This tufa, better known by the name of cappellaccio, is very bad. The
only buildings in which it was used, besides the inner wall of the
Servian agger, are the platform of the temple of Jupiter Capitolinus, in
the gardens of the German Embassy, and the "puticuli" in the
burial-grounds of the Esquiline. Its use must have been given up before
the end of the period of the Kings, in consequence of the discovery of
better quarries on the right bank of the Tiber, at the foot of the
hills now called Monte Verde....

They cover a space one mile in length and a quarter of a mile wide on
each side of the valley of Pozzo Pantaleo. In fact, this valley, which
runs from the Via Portuensis toward the lake of the Villa Pamphili,
seems to be artificial; I mean, produced by the extraction of the rock
of millions of cubic meters in the course of twenty-four centuries. If
the work of the ancient quarrymen could be freed from the loose material
which conceals it from view, we should possess within a few minutes'
drive from the Porta Portese a reproduction of the famous mines of El
Masarah, with beds of rock cut into steps and terraces, with roads and
lanes, shafts, inclines, underground passages, and outlets for the
discharge of rain-water. When a quarry had given out, its galleries were
filled up with the refuse of the neighboring ones--chips left over after
the squaring of the blocks; so that, in many cases, the color and
texture of the chips do not correspond with those of the quarry in which
they are found. This layer of refuse, transformed by time into humus,
and worked upon by human and atmospheric forces, has given the valley a
different aspect, so that it looks as if it were the work not of
quarrymen, but of nature.

Tufa may