ontinually
changing, it is the most changeless of all things. For ever passing
away, it is yet the most steadfast and enduring. Derived from the
fleeting vapour--the emblem of inconstancy--it outlasts the most solid
structure of man, and continues to well up its waters even when the
rock beside it has weathered into dust. The Fountain of Egeria flows
to-day in the hollow of the Coelian Hill as it flowed nigh three
thousand years ago, although the muses have fled, and the deities
Picus and Faunus, which Numa entrapped in the wood of the Aventine,
have gone back to their native skies with Jupiter; and Mammon and
Philosophy have exorcised that unseen world which once presented so
many beauties and wonders to the imagination of man.

A little farther on to the right, a side path, called the Via
Antonina, leads up to the stupendous ruins of the Baths of Caracalla,
a mile in circumference, and covering a space of 2,625,000 square
yards. The walls, arches, and domes of massive brickwork hanging up in
the sky,--the fragments of sculpture and splendid mosaic pavements
belonging to these baths,--produced a deeper impression upon my mind
than even the ruins of the Colosseum. With the form and majesty of the
Colosseum, owing to its compactness and unity, pictures and other
representations have made us familiar from infancy, so that it excites
no surprise when we actually visit it; but the Baths of Caracalla
cannot be pictorially represented as a whole, on account of their vast
variety and extent, and therefore we come to the spectacle wholly
unprepared, and are at once startled into awe and astonishment.
Notwithstanding the wholesale pillage of centuries, enough in the way
of chambers and baths, marble statues, pillars, and works of art,
still remains in this mountainous mass of masonry to witness to the
unparalleled luxury by which the strength of the Roman youth was
enervated, and the foundations of the empire sapped. Shelley wrote on
the summit of one of the arches his "Prometheus Unbound;" and
certainly a fitter place in which to seek inspiration for such a theme
could not be found.

Beyond the Baths, on the same side of the road, is the most
interesting little church of the two saints Nereus and Achilles,
Christian slaves who suffered martyrdom in the reign of Diocletian. It
is supposed that the Nereus whose body reposes in this ancient church
is the person referred to by St. Paul in his greetings to the Roman
saints at the