d under a prodigious mass
of earth, together with a large section of an adjoining cemetery. In
fact, columbaria dating from the time of Hadrian have been found built
against the beautiful inscription of Lucilia Polla; and the
inscription itself was disfigured by a coating of red paint, to make
it harmonize with the color of the three other walls of the crypt. The
whole tract between the Salaria and the Pinciana was raised in the
same manner twenty-five feet; and contains, therefore, two layers of
tombs,--the lower belonging to the republican or early imperial epoch,
the upper to the time of Hadrian and later.

Where did this enormous mass of earth come from?

A clew to the answer is given on page 87 of my "Ancient Rome," where,
in describing the construction of Trajan's forum, and the column which
stands in the middle of it, "to show to posterity how high rose the
mountain levelled by the emperor" (_ad declarandum quantae
altitudinis mons et locus sit egestus_), I stated that I had been able
to estimate the amount of earth and rock removed to make room for the
forum at 24,000,000 cubic feet, and concluded, "I have made
investigations over the Campagna to discover the place where the
twenty-four million cubic feet were carted and dumped, but my efforts
have not, as yet, been crowned with success." The place is now
discovered. None but an emperor would have dared to bury a cemetery so
important as that which I am now describing; and if we remember that
it was the open space which was nearest of all to Trajan's
excavations, easy of access, that the burying of a cemetery for a
necessity of state could be justified by the proceedings of Maecenas
and Augustus, described on page 67 of the same book, and that the
change must have taken place at the beginning of the second century,
as proved by the dates, and by the construction and type of tombs
belonging respectively to the lower and upper strata, I think that my
surmise may be accepted as an established fact.

Thus vanished the mausoleum of the Lucilii from the eyes and from the
memory of the Romans of the second century. Towards the end of the
fourth century the Christians, while tunnelling the ground near it,
for one of their smaller catacombs, discovered the crypt by accident,
and occupied it. The shape of this crypt may be compared to that of
Hadrian's mausoleum; that is, it was a hall in the form of a Greek
cross, in the centre of the circular structure, and was reach