iches of this river,
that the Jews have formerly proffered the Pope to cleanse it, so they
might have for their pains what they found in the bosom of it. I have
seen the valley near Ponte Molle, which they proposed to fashion into a
new channel for it, until they had cleared the old for its reception.
The Pope, however, would not comply with the proposal, as fearing the
heats might advance too far before they had finished their work, and
produce a pestilence among his people; tho I do not see why such a
design might not be executed now with as little danger as in Augustus's
time, were there as many hands employed upon it. The city of Rome would
receive a great advantage from the undertaking, as it would raise the
banks and deepen the bed of the Tiber, and by consequence free them from
those frequent inundations to which they are so subject at present; for
the channel of the river is observed to be narrower within the walls
than either below or above them.

Next to the statues, there is nothing in Rome more surprizing than that
amazing variety of ancient pillars of so many kinds of marble. As most
of the old statues may be well supposed to have been cheaper to their
first owners than they are to a modern purchaser, several of the pillars
are certainly rated at a much lower price at present than they were of
old. For not to mention what a huge column of granite, serpentine, or
porphyry must have cost in the quarry, or in its carriage from Egypt to
Rome, we may only consider the great difficulty of hewing it into any
form, and of giving it the due turn, proportion, and polish. The most
valuable pillars about Rome, for the marble of which they are made, are
the four columns of oriental jasper in St. Paulina's chapel at St.
Maria Maggiore; two of oriental granite in St. Pudenziana; one of
transparent oriental jasper in the Vatican library; four of Nero-Bianco,
in St. Cecilia Transtevere; two of Brocatello, and two of oriental agate
in Don Livio's palace; two of Giallo Antico in St. John Lateran, and two
of Verdi Antique in the Villa Pamphilia. These are all entire and solid
pillars, and made of such kinds of marble as are nowhere to be found but
among antiquities, whether it be that the veins of it are undiscovered,
or that they were quite exhausted upon the ancient buildings. Among
these old pillars, I can not forbear reckoning a great part of an
alabaster column, which was found in the ruins of Livia's portico. It is
of th