upper lake, and forms a junction with the water from the Alsietina Lake,
near the bank of the latter, at the south end of that lake. The _specus_
of the Alsietina of Augustus is a tunnel cut in the rock[107]. The Lacus
Sabatina[108] is at the elevation of about 523 ft., and therefore 156
ft. below the Alsietina. Augustus drew an additional supply of water
from this lake, and this portion only of the aqueduct of Augustus was
restored by Trajan. The water for this was not drawn from the lake
itself, but from the springs that supply the lake on the western shore,
the side most distant from Rome. Some of the work of the time of Trajan
is visible there. The _specus_ of the Alsietina has been traced to the
point of junction with the Aqua Paola (this water having been restored
to use by Pope Paul III., A.D. 1540), and it still supplies the district
of the Trastevere. It does not appear that Trajan used the water of
the Alsietina at all, but the engineers of Pope Paul evidently did so;
a tunnel, or _specus_, from that lake having been made in the time
of Pope Paul, the entrance to which remains, with the grooves for a
flood-gate[109]. After the junction with the Aqua Paola, the old wells
can no longer be traced; their place is supplied by the constructions
called _respirators_, each of which is a small square structure
surmounted by a pyramid. These are evidently built over the wells, and
very rudely constructed of the stone of the country, worked rough.
When we arrive at the Osteria Nuova,—which is near the site of the
ancient city of Cariæ[110], mentioned by Frontinus, and the old village
of S. Maria in Celsano, the point of junction of the Alsietina and
Sabatina,—there are evident marks of another junction of aqueducts there.
The house itself, now used as an _osteria_ or hostelry (_auberge_), is
made out of an ancient Castellum Aquæ, as is frequently the case with
similar houses in the country round Rome, and sometimes even within the
walls. At about half a mile from this _osteria_, in a hollow, is a white
house called Casale Bianco; and close to this is a fountain, supplied by
a spring which runs into a _specus_. This water, being one of the sources
of the Aqua Paola, passes through the hill at a considerable depth. At
about half the distance between this and the _osteria_ is a remarkable
passage for the Aquarii into the tunnel by a very steep descent, passing
sideways across the _specus_ of the Aqua Paola, and going on to a much
greater depth to the Aqua Alsietina[111]. This passage is 150 ft. in
length from the surface of the hill, and 70 ft. in perpendicular depth,
with ninety steps, of which only a few at the top are visible; the others
are covered with earth. The water still runs through the upper _specus_,
and is still in use, but not through the lower one[112].
From the valley beneath the sloping passage for the Aquarii, near the
Osteria Nuova, Nibby[113] traced the Alsietina as a tunnel cut in the
tufa rock, a part of which he saw near an oil mill. The _specus_ then
followed the low ground from the tenements of S. Niccola, Porcareccina,
Maglianella, and from the Villa Panfili, to the principal gate of the
monastery of _S. Cosimato_ (or SS. Cosmas and Damian in the Trastevere),
where it is stated by Cassio[114] that the _specus_ was found in 1720,
about thirty feet underground. The Naumachia of Augustus is said to have
been near this monastery.
The complaints of Frontinus appear to have been listened to by the
Emperor, and great changes and improvements were made in this aqueduct
under his direction, in the time of Trajan; this is in fact the same
as the Aqua Trajana (see X.), and the water still comes from the Lacus
Sabatina, but not from the Alsietina. In going from Rome, the respirators
can be followed across Monte Mario, and near the high road that passes
over Ponte Molli, to the point of junction about ten miles on the road
to the Cariæ [now Osteria Nuova]. Here the respirators cease; but their
place is supplied by a line of old wells descending into the subterranean
_specus_, which follows the line of the _old road_. This is not always
the same as the new one. The other branch, which supplied the Naumachia,
was the only one made in the time of Augustus. Paul V. repaired this
aqueduct along the whole line, restored it to use, and put up in various
places inscriptions recording this, in which he calls it the Aqua
Alsietina[115]. The last of these is on his fountain at the mouth of the
aqueduct, where the water still gushes out in great abundance, as it did
in the sixth century, when it was observed by Procopius; this is on the
Janiculum, above S. Pietro in Montorio, the highest ground in Rome.
VIII., IX. THE CLAUDIA AND ANIO NOVUS (A.D. 52).
“Afterwards Caius Cæsar, (Caligula,) who succeeded Tiberius,
considered seven aqueducts scarcely sufficient for public
purposes and private amusements, and began two new aqueducts in
the second year of his rule as Emperor, when Aquilius Julianus
and P. Nonius Asprenas were consuls (i.e. A.D. 38), in the year
of Rome 789, which work Claudius in a most splendid manner
finished and dedicated, on the calends of August, in the year
of the city 803 (i.e. A.D. 52), when Sulla and Titianus were
consuls[116].
“To one, which was brought from the springs of Cæruleus and
Curtius, the name of _Claudia_ was given. This one is next in
order of excellence to the Marcian.
“The other, because two streams of the Anio had begun to flow
into the city, so that they should be more easily distinguished
by their names, began to be called _Anio Novus_. It ruins all
the others[117]. To the former Anio the cognomen of _Vetus_ was
added[118].
“The Anio Novus and Claudia are carried from the _piscinæ_ upon
higher[119] arches, so that the Anio is the highest of the two.
Their arches come to an end after the Pallantian Gardens, and
thence they are carried down in pipes for the use of the city.
“But first of all the Claudia transfers a part of its water
on to the arches which are called the Neronian, at the _Spes
(Specus) Vetus_. These, being continued in a direct line
along the Mons Cœlius, are terminated close to the temple of
Claudius. They disperse the quantity which they had received
either about the ‘Mons Cœlius’ itself, or in the Palatine, in
the Aventine and the Transtiberine Region[120].”
VIII. THE CLAUDIA.
“The Claudia begins on the Via Sublacensis[121], at the
thirty-eighth milestone, about 300 yards off the road towards
the left. There are two very large and beautiful springs,
one called Cæruleus, from its blue appearance, the other
Curtius[122]. It receives also the spring which is called
Albudinus, of such excellence, that when there is need of
adding it to the Marcia, the latter loses none of its quality
by the addition. The spring of the Aqua Augusta, because the
Marcian seemed to be sufficient for itself, was turned aside
into the Claudian; nevertheless it was retained as a protection
for the Marcian, but so that the Augustan might be added to
the Claudian, if the channel of the Marcian was not capable of
receiving it[123].
“The channel of the Claudia is 46 miles, 406 paces in length;
of this, 36 miles, 230 paces is by a subterranean course: on
work above ground 10 miles, 176 paces, and out of this on
arched work, in many places in the upper part, 3 miles, 76
paces; and near the city from the seventh milestone, by a
substructure of channels for 609 paces, on arched work 6 miles,
491 paces[124].
“The Claudian was the second in height as to level[125].”
IX. THE ANIO NOVUS.
“The Anio Novus, at the forty-second milestone, on the _Via
Sublacensis_, at _Simbruinum_[126], is taken out of the
river, which, since it has about it cultivated land in a rich
territory, and so very loose banks, flows muddy and turbid
even when uninfluenced by violent rains; and therefore at the
very entrance of the channel is placed a cistern for the mud
(_piscina limaria_), so that the water on its way from the
river to the _specus_ should settle and become clear. From this
cause also when heavy showers come down, the water flows into
the city in a muddy state.
“There is joined to it the _Rivus Herculaneus_[127] which rises
on the same road at the thirty-eighth milestone, in the same
neighbourhood as the springs of the Claudian, on the other side
of the river and the road. This is very pure by nature, but
when mixed it loses the advantage of its freshness.
“The channel of the Anio Novus is in length 58 miles, 700
paces. Out of this 49 miles, 300 paces is by a subterranean
channel;—on work above ground 9 miles, 400 paces; out of this
on substructure or on arched work in several places in the
upper part 2 miles, 300 paces, and nearer the city, from the
seventh milestone, on a substructure of channels 609 paces, on
arched work 6 miles, 491 paces. These are the highest arches,
elevated in some places 109 feet[128].
“Nor was it enough for our Emperor [Nerva] to have restored an
abundant and pleasant supply of water in the other aqueducts;
he thought he saw his way to getting rid of the bad qualities
_even of the Anio Novus_, he therefore ordered the _source to
be changed from the river_, which was now left alone, and taken
instead _from the lock in which_ the water was most pure, and
which _is situated above Nero’s villa on the lake_ (_super
villam Neronianam Sublaquensem_[129]);” i.e. at Subiaco, now a
medieval castle and a modern town.
“But the water of the Anio Novus often spoilt the rest, for
since it was the highest as to level, and held the first rank
as to abundance, it was most often made use of to help the
others when they failed. The stupidity, indeed, of the Aquarii
was such that they introduced this water into the channels
of several others where there was no need, and spoilt water
which was flowing in abundance without it. This was the case
especially as regards the Claudia, which came all the way for
many miles in its own channel perfectly pure, but when it
reached Rome, and was mixed with the Anio, lost all its purity.
And thus it happened that most of the streams were not in fact
helped at all by the addition of the extra water, through the
want of care on the part of those who distributed it[130].”
THE NERONIAN ARCHES.
“Amongst those abuses which seemed to require reform, may
be mentioned what took place regarding the supply to the
Cœlian and Aventine hills. These hills, before the Claudian
was supplied to them, were accustomed to use the Marcian and
Julian; nevertheless, when the Emperor Nero gave them the
Claudian raised to a greater height on the series of arches
extending to the Temple of Claudius, where it was distributed,
the older streams, instead of yielding an increased supply,
were lost altogether. He made no new castella [for the
Claudian], but used those which were there, and which
retained their names, although the water brought to them was
different[131].”
THE RIVER ANIO.
The highest source of the river Anio, or Aniene, is in a gorge in the
highest part of Mount Cantaro, about 63 miles from Rome. This spring
never fails in the hottest and driest weather, and is always cool; it
is situated in the close or (_serra_) of St. Antonio, and is called
_La Canala_, or the canal at the gate of the small castle or fortified
village of Filettino. Pliny says[132] that it rises in the territory
of Treba[133]. In going from Filettino towards Trevi the road has an
ancient pavement, and on the left-hand side is a magnificent substructure
of Cyclopean character called _Mura Saracine_, against the cliff. In
1857 Signor Gori saw some of the large stones of this fine ancient
substructure thrown down to the banks of the stream, to make the
foundations of a small bridge across it. The stream receives several
accessions from other springs in its course, two from a cave called
Pertusu, the small limpid stream called Suria, on the hill of Trevi,
and another called Capo d’Acqua. The Anio thus augmented falls in two
cataracts, or cascades, near Pertusu, and passes under the Ponte delle
Tartare with much violence. This bridge is a natural arch of rock formed
by the force of the water piercing it. The river then passes on through
a gorge in the mountain-pass in small waterfalls, especially at a place
called Pendema, where in 1855 an ancient mosaic pavement and a wall of
reticulated masonry were found.
At the two bridges of Communacchio (_comune acqua_), where an
amphitheatre of mountains and the castle of Valle-pietra are situated,
another stream coming from the mountains of the Trinitá and Autore, the
highest in that district, joins the Anio.
In the basin of Valle-Pietra, two fine cascades fall over the massive
rocks and unite in a single stream. From the bridge of Communacchio
a road leads to Arcinazzo, situated in a large plain, surrounded by
the mountains, with several roads leading into it. One of these from
Palestrina, passing by Piglio, is an ancient paved road, and some persons
consider that an arcade of Cyclopean masonry, near Guarcino, carried an
aqueduct to the _thermæ_ there. On the south-west side of this plain
are the ruins of an imperial villa, commonly called of Nero; but two
inscriptions found there upon leaden pipes in 1860, shew that it was of
Trajan[134]. Great quantities of marble were dug up here in the time of
Pius VI., A.D. 1795.
The river passes below the monastery of S. Benedict, called the Sacro
Speco, and a little lower down, the monastery of S. Scholastica, both
of which stand on the brink of a precipice, over which the Anio makes a
large and picturesque waterfall, and passes under the bridge of S. Mauro
or Piedilago, where the rocks approach so closely as to leave only a
narrow passage, which was formerly closed by a gigantic wall, forming a
long lake or lock. The stream now passes through the ruins of the wall,
the demolition of which was caused in 1305 by two ignorant monks, who
pierced a hole at the foot of the wall, the result being that the whole
country was inundated up to the walls of Rome, and serious mischief done,
as recorded in the anonymous chronicle of the monastery[135].
On the banks of the lake are the ruins of a villa of early character,
called Casa de’ Saraceni and Carceri, with a _nymphæum_ and baths. At
Pianigliu, are other ruins on an enormous scale.
Subiaco is more than two thousand feet above the level of Rome, and
all the foregoing description applies to the part of the river above
Subiaco. In all this upper part of the stream, the river Anio has very
much the character of a large mountain-torrent rushing through the rocks
with great violence. It usually appears to be a clear stream of beautiful
water, excepting in time of floods, when the clayey soil is brought down
into the stream and makes it muddy. To guard against this evil, Nero made
his great lakes, which do not correspond at all to the usual English
idea of a lake, by which is commonly understood a considerable sheet of
water, like the Swiss lakes or the lakes of Westmoreland, Scotland, and
Wales. The Roman word _lacus_, and the modern Italian _lago_, may mean
a lake of this description also; but it includes a reservoir of water
of any kind. We are expressly told in the _Breviarium_, at the end of
the Catalogue of the Regionaries, that a _lacus_ is a well, _puteus_,
and the numerous _lacus_ of that Catalogue are the same as the _castella
aquarum_ of Frontinus, within the walls of Rome. These justly-celebrated
lakes of Nero are in fact portions of the river Anio, intercepted in a
gorge of the rocks about a mile above Subiaco, and are formed by cutting
away some large pieces of the rock on each side in large masses, and with
these building a great high and massive wall across the stream, forming
an effectual barricade or dam to stop the water and raise it to the level
of the top of this great wall. There were three of these walls across
the stream, over each of which the river fell in tremendous cascades.
The first loch (_lacus_) commenced at the Mola di Ienne, where the first
great wall of enclosure is situated. The second at the cascade of the
river, under the great monastery of S. Benedict, and called “the Sacred
Specus,” from a cave in which the saint is said to have lived, extends
to the bridge called Ponte di S. Mauro, where the _specus_ of Trajan
commenced. The third is from the Ponte di S. Mauro, through a gorge,
where the wall of enclosure is visible. Here was the Piscina Limaria of
Claudius, and the _specus_ of the Anio Novus originally commenced at the
Emissarium, restored by Cardinal Barberini. This was made by Claudius,
but was abandoned by Trajan, because the earth from the adjoining fields
had fallen between the river and the _specus_.
The Villa Sublacensis of Nero was below the level of the upper lake or
loch, as mentioned by Frontinus. This was just above the present bridge
called S. Mauro or Piè-di-lago, which seems to be made upon the two ends
of the dam. This dam, wall, or barricade, was quite 150 feet above the
surface of the water in ordinary times. The bridge is still 144 feet
above the water by measurement, and the _specus_ is nearly ten feet
higher. This _specus_ or conduit is cut in the rock of the cliff on the
side of the valley, at the level at which the water originally stood in
this lake or loch; the wall was a few feet higher, in order to force a
portion of the water to pass through the _specus_ before the rest fell
over the cascade. There are ruins of the _piscinæ_ on the bank where
the _specus_ began, and of the villa of Trajan on both sides of the
loch, with the well-known brickwork and _Opus Reticulatum_ as facings
for the walls. These magnificent cascades still remain, being a natural
formation; but as the bed of the river is very deep, they are much
concealed by the banks, and the shrubs upon them. The great walls or dams
of Nero and Trajan being brought out to the edge, the cascades falling
over them must have had a much finer effect, although the natural site is
extremely grand and most picturesque; in fact it is celebrated among all
the landscape painters of Italy, the scenery about Subiaco being among
the finest of its kind of river and mountain scenery that is known. The
enormous reservoirs or lakes, or lochs of Caligula and Claudius (commonly
called of Nero), cover the space between the natural cascade and the
outer wall of rock artificially constructed, over which the water was
made to fall. When the ignorant monks in the fourteenth century made an
aperture in the great wall or dam, the force of the water soon enlarged
it, and washed the whole structure away, leaving the great masses of
stone or rock, of which it had been built, scattered in the stream below
as if they were natural rocks, where they still remain. The object of the
monks was to release their fields adjoining to the monastery above the
falls from a temporary flood.
The _specus_ is nearly six feet high, and only sixteen inches wide; the
men must have cut it standing sideways. There are apertures into it at
intervals now open, and there probably always were such openings for
the use of the _aquarii_ to keep the course clear. The _specus_ which
Frontinus calls _subterraneus_, although that is _literally_ true, does
not mean exactly what we now call a tunnel; but this _specus_ is cut
in the rock of the cliff, with a few feet of stone only as an outer
wall to it, and in this manner it is continued along the edge of the
valley of the river Anio for many miles, always on the left side of
the river in going towards Rome. An old road runs by the side of it,
not now used for carriages, but remaining as a cart-road only; this
must be the Via Sublacensis of Frontinus. Another road runs along the
right-hand side of the valley, and is the one now in use: this is the
Via Sublacensis Neroniana of the time of the Empire. The valley varies
in width very much, in some parts it is three or four miles wide; this
is the case where the springs of the Marcia and the Cerulean Lake gush
out from the rock under the _diverticulum_ of the Via Valeria or present
carriage-road, on the right-hand side of the valley.
The lowest of the three lakes of Claudius above Subiaco was circular, the
rock being cut away to a half circle on each side of the stream; into
this great basin the grand cascade fell from the second lake. The lowest
lake or loch was comparatively not very deep. It seems most probable that
the lowest reservoir was intended to serve for the Aqua Claudia. The
_specus_ has not at present been traced quite so far; but it is found
a little lower down, above the modern paper-mill. This is more than a
hundred feet below the level of the Anio Novus. It may be that this was
one of the springs that fell into the Anio, and was intercepted for the
aqueduct. It is probable that the same was the case with the Anio Vetus,
as we know it was with the Marcia; but as the water from the springs
sometimes ran short in dry seasons, the Anio Novus was taken from the
river itself, a part of which was turned into it from the great lake or
loch. For this reason that water was always more abundant than all the
rest, and was used to supply the deficiency in case of need, as Frontinus
tells us. This _specus_ can be entered and examined; it is here a tunnel
made in a rock of soft stone, with fissures filled with clay. The
_specus_ is lined with brick, and covered with large flat tiles, placed
at an angle, so as to form a roof sloping down to the two sides from the
ridge in the middle. There are inscriptions recording repairs by Cardinal
Barberini, nephew of Urban VIII. This _specus_ is that of the Anio Novus,
constructed by Claudius; that of Trajan is about half-a-mile above the
town of Subiaco, and on the right-hand side of the river Anio, not on the
left, as the Anio Novus is.
The thirty-eighth milestone on the Via Sublacensis was found by Fabretti
_in situ_, and the thirty-eighth milestone in the Via Valeria, now at
Arsoli, is said by Gruter[136] to have been formerly at _La Sonnoletta_,
or _ad fontem Somnulæ_: so that the two sources of the Claudian water,
called Cæruleus and Curtius, were at the lake now called S. Lucia, in the
territory of Arsoli; and the source called Albudinus is the _first_ of
the four springs now called _Acque Serene_, while the other springs of
the same name formed the _Aqua Marcia_.
The _Piscina Limaria_, referred to by Frontinus as erected by Claudius
for filtering the stream, at the entrance of the Anio Novus, at the
forty-_second_ mile[137] on the Via Sublacensis, is visible at the
_Parata della Cartiera_ of Subiaco. This _piscina_ is not covered over,
but open at the top, and is excavated in the rock of the bed of the river
Anio, with a great declivity and with four cascades to throw down the
sand, wood, and weeds brought down the river, and so to purify the water;
but as it was still liable to become muddy in the time of floods, Trajan,
according to Frontinus, excavated another _specus_ in the rock of the
mountain near the Ponte di S. Mauro, where the great wall of the lake was
situated[138].
The _specus_ of the Claudia seems to have been carried on the right-hand
side of the valley as far as Vicovaro, about half-way to Tivoli, and then
across the valley on an arcade, and carried on under the Anio Novus, and
above the Marcia and Anio Vetus. All of these seem to be at different
elevations on the side of the hill to the left of the valley, until they
arrive at another valley crossing this, called the Valley of the Arches,
about two miles from Tivoli, where they were carried across upon arcades.
On these ancient arcades, or out of the materials of them, modern bridges
have been made, both at Vicovaro and in the Valley of the Arches. The
ruins of these splendid arcades are among the finest and most picturesque
ruins of the Roman empire.
After passing the bridges across the valley of the Anio, the Anio Novus,
Marcia, and Anio Vetus are continued along the side of the hill in what
may still be called the cliff of the valley of the Anio, to _near_ the
cascades at Tivoli, at different levels, the Anio Novus considerably
higher than the others. To avoid the cascades here the aqueducts wind
round the end of the hill. In going out of Tivoli to the promenade of
Carciano, on the side towards Rome, there is a large college of the
Jesuits on the left hand, the _specus_ of the Anio Novus passing under
this, and through a wine-cellar. About a quarter of a mile out of the
town, two _specus_ are visible on the side of the hill above the road or
promenade, and these may be traced at short intervals for miles, with
openings into them in several places. The lower one is the Marcian,
passing in a more direct line, and further from Tivoli, and is generally
cut in the rock as a tunnel; the upper one is the Anio Novus, and is in
some places faced with brick or with _Opus Reticulatum_, where it has to
cross an opening. The Aqua Marcia here passes at a lower level below the
road, with reservoirs at intervals, as already described.