and probably connected. They are mentioned together in the Regionary
Catalogue as in the first Regio, and there are remains of them under
the small hill, called Monte d’Oro, probably, from the golden colour
of the sand in its original state, which is situated just within the
Porta Latina, between that and the Porta Metronia. Some excavations were
made there in 1870 by the Archæological Society, and large subterranean
chambers and corridors were found similar to those under the Thermæ of
Antoninus Caracalla. The _specus_ of an aqueduct was also followed for
a considerable distance in the direction of the Porta Latina. This must
have been for the Aqua Severiana. Just outside of that gate are remains
of two _piscinæ_ or _castella aquarum_, one on either side, and on
different levels. One of these belonged to the Aqua Aurelia, the other
to the Severiana. The course of this latter is more doubtful, but it was
probably only a branch from one of the great aqueducts, and would appear
to have come in the bank on which that part of the wall of Aurelian was
built, from the Porta Metronia to the Porta Latina. It arrived at the
bridge over the Almo (on which the gateway-arch of the Porta Metronia is
built), from the great _piscina_ and _castellum aquæ_, on the cliff of
the Cœlian, near the Porta Capena and the Camenæ, where two aqueducts
are now visible, having been brought to light by the excavations of the
Archæological Society. The construction of one of these aqueducts agrees
with the time of Septimius Severus.
XIV. ANTONINIANA, A.D. 215.
This aqueduct enters Rome at the south-east corner near the Porta di S.
Sebastiano, and passes over the arch of Drusus; a part of the arcade is
visible by the side of it. The _specus_ can be seen both in the wall of
the city, through which it passes, and over that arch, and one of the
arches of the arcade remains on the east side of it. It was carried in
that manner for some distance across the valley or foss, until it reached
the high bank of earth on which the Wall of Aurelian is built, near the
Porta di S. Sebastiano, and then along the edge of that bank, which is
the great _agger_ of the ancient earthworks, against the outer side
of which the Wall of Aurelian is built. The inner side of the bank is
supported by a low wall here as in many other parts, and upon or against
that inner wall the _specus_ of the aqueduct is carried. It is sometimes
on an arcade, in other parts it is carried on the wall to the Thermæ of
Antoninus Caracalla. The demolition of part of this arcade in modern
times is recorded by contemporary authors.
The _specus_ passed upon an arch over the road in the old foss outside
the wall into a garden on the opposite side, where it can be seen on
the level of the ground; thence it can be traced through that large
garden or vineyard as far as the railway, which passes on the outer
side of it in a deep cutting. The remains of the brick arcade here form
a wall between this garden and another. It is covered with shrubs, and
looks like a hedge, from which circumstance it has hitherto escaped
observation. The wall is cut through by the railway, but can be traced
on the other side of it along the bank of a narrow deep lane, like what
we call in England a Devonshire lane. This lane goes parallel to the
Via Latina, on the southern side of it, for about a mile; the aqueduct
then leaves it, turning short to the left. Near to this angle, at about
half-a-mile outside of the Porta Latina, is a large reservoir belonging
to this aqueduct. It is built against the western cliff of the valley
of the Caffarella, the top of it level with the summit of the cliff,
and therefore is not visible from above, as a person standing on the
higher ground looks over it. It is also hidden by a clump of trees;
but it is very distinctly visible from the valley below, and from some
parts of the Via Appia, and is readily seen to be a _castellum aquæ_ by
the boldly-projecting buttresses to support the wall with the weight
of water behind it. The Aqua Antoniniana ran along the edge of the
cliff, and supplied this large reservoir, which is oblong as usual, and
divided down the middle by an arcade, similar to the fine one of the
Marcian near Tivoli, and many others. This has been plastered over, and
made into a cow-house. It is far above the level of the Aqua Aurelia,
which runs below along the side of the valley of the Caffarella. The
Aqua Antoniniana clearly came from the higher aqueducts in the main
line; and, according to the Einsiedlen Itinerary, it was a branch of the
Marcian which went to supply the Thermæ of the Antonines called that of
Caracalla. Part of the brick arcade, with the _specus_ upon it, is here
visible in another garden against a cliff; it then passes underground
for a short distance, but soon emerges again, and can be traced against
another cliff as far as the Via Latina, which is here upon a bank, or
rather on the edge of higher ground, with the remains of a _piscina_
by the side of it. The _specus_ then again passes underground for some
distance, and the next point where we have been able to find it is an old
stone quarry, the vault of which fell down in 1870, and revealed this
_specus_, which was not visible before. This is in the garden behind the
Albergo de’ Spiriti, on the Via Appia Nova, about two miles from Rome,
and near the point where it crosses the old Via Latina[184].
A large reservoir remains near the Porta Furba, about a quarter of a
mile nearer to Rome, and just two miles from the Porta Maggiore. Here we
excavated (in 1871) this large subterranean reservoir, near the Claudian
arcade on the southern side, but not very close to it, rather nearer to
the road to Tusculum (Frascati), which passes near the Porta Furba. This
reservoir appears to have belonged to the Anio Vetus, which agrees with
the account in Frontinus, of a branch of the Anio Vetus at two miles from
Rome, going in the direction of a new road. The _specus_ crosses the
Via Appia Nova near the Albergo de’ Spiriti, and the Via Appia Nova was
probably a new road in the time of Frontinus, as indicated by the tombs
of the first century along the side of it.
XV. ALEXANDRINA, A.D. 225.
The Aqua Alexandrina is distinctly mentioned by Lampridius in his life
of Alexander Severus (c. 25), as made to bring water to his _thermæ_,
which were near those of Nero, and therefore near the Campus Martius
and the Pantheon in Regio IX. This could only have been a branch from
the Virgo[185], as there is no aqueduct of the third century along the
Cœlian, and no trace of a branch from the Palatine or the Capitol.
There is no probability in the theory of Fabretti, that the great
aqueduct coming from Gabii, on the eastern side of Rome[186], was the one
mentioned in the life of Alexander Severus as made by him to carry water
to his _thermæ_, near those of Agrippa, in the Campus Martius, on the
northern side of Rome. A branch from the Virgo on the Pincian, or from
one of the great reservoirs on the eastern side of Rome, could be made at
a tenth part of the cost. There is some reason to believe that there was
such a branch passing near the Barberini palace.
Another branch may very well have been made from the great aqueducts
between the Porta Maggiore and the Porta S. Lorenzo, to the Nymphæum of
Alexander Severus, on the Esquiline in Regio V. An inscription relating
to this is said to have been found at the _piscina_ in the garden of S.
Croce[187]. It is far more probable that this inscription was found on
the wall of the great reservoir, on the other side of the Via di S. Maria
Maggiore, near the Minerva Medica, where other reservoirs of extensive
_thermæ_ of the third century are visible[188]. These were supplied with
water from other reservoirs just within the Porta Maggiore belonging to
the different aqueducts; the Anio Vetus, the Marcian, and the Claudian,
all appear to have contributed their share. The one specially called
Alexandrina was probably the lofty one carried upon a tall arcade, from
the reservoir of the Claudia near the Baker’s tomb,—forming part of the
present city wall. The lower part of the piers of the arcade of this
period may be seen built up in the wall; the arches lead to another
reservoir between that and the building called the Temple of Minerva
Medica, and are there brought to an end, just on the south side of the
new arches made for the railway. The _specus_ or conduit, and the arches
for it, on these brick piers of the third century, have been rebuilt for
the Aqua Felice, in the same rough way as that _specus_ is usually built;
but, as that conduit is carried on to the Porta S. Lorenzo in the wall,
and as these piers of the third century cease exactly at the point where
the conduit of that period would naturally turn off, there seems every
probability that this was the Aqua Alexandrina, which was merely a branch
from the Claudia and Anio Novus united to supply these _thermæ_, just as
the Aqua Antoniniana was a branch from the Marcia to supply the _thermæ_
of Antoninus Caracalla.
The _specus_ of this branch was carried over the Julia on the Marcian
arcade to the point where it terminates, which is exactly in a line with
a lofty _piscina_ and _castellum aquæ_, now a gardener’s house, between
the wall and the Minerva Medica, and there are remains of the tall arcade
from one to the other; the last pier which joins to that building looks
like a large tall buttress to it.
The Temple of Minerva Medica is a brick building of the third century,
agreeing with the time of Alexander Severus, and there has evidently been
a fountain of importance in the middle of it, with an aqueduct to carry
water to it from the large _castellum_ near to it. Upon this _castellum
aquæ_ a villa of the sixteenth century has been built; but the vaulted
chambers, with the tartar deposit of water, remain in the lower part of
this building, and there is a tomb or _columbarium_ of the third century
at one end of it.
The dedication of a temple to Minerva Medica, in connection with an
aqueduct, is natural, and that this was not an isolated example is shewn
by an inscription found near Subiaco[189], and published in 1830 by
Martelli, in his work on the Antiquities of Sicily[190]. The Regionary
catalogue of the fourth century gives, in the fifth Regio, which contains
the Esquiliæ, the Nymphæum of Alexander and the Minerva Medica, all
which agrees with the existing remains of this Nymphæum. In the same
vineyard, to the north-west or opposite side of the Minerva Medica, and
very near to it, are the ruins of another building, called by some “a
_nymphæum_,” now also a gardener’s house, under which the marble pavement
remains very evident, the construction belonging to the period of
Alexander Severus[191].
Both the Pantheum or hall for the men, and the Nymphæum or hall for the
women, had images in the niches round them, and frequently an altar
also, so that they were temples at the same time that they were used as
waiting-rooms for the baths. The Pantheum of Agrippa was the entrance to
his _thermæ_[192]; the building usually called _the Temple_ of Minerva
Medica, from an image found there, is called in the Regionary Catalogue
Minerva Medica only. A Nymphæum and a Pantheum equally required a
_castellum aquæ_ to supply it with water for the fountains and the stream
that ran round it, and there are remains of bath-chambers and niches
outside of many of the larger reservoirs, as in this instance.
During some extensive excavations, which were carried on in the spring
of 1871 by a company, with a view to building new streets in the eastern
part of Rome, considerable remains of the lower part of the walls of
these great _thermæ_ of the third century were found on both sides of the
road made in the sixteenth century, from S. Maria Maggiore to S. Croce.
The company bought two large vineyards, in one of which stands the fine
ruin called Minerva Medica, which was evidently one of the halls of the
_thermæ_; the ground is full of ancient reservoirs for water at different
levels, some underground, others at a considerable elevation, turned into
houses; they may be traced at intervals all along the line within the
Wall of Aurelian, from the Porta Maggiore to the Porta S. Lorenzo, which
is itself here built against the Marcian arcade, and in one part the
outer wall of the large _piscina_ and _castellum aquæ_ of the Tepula is
incorporated with the wall, of which it now forms part. This ground had
been at one period the Esquiliæ or great burial-ground, and afterwards
the garden of Mæcenas, so that remains of great works for the supply of
water at different periods were likely to be found there, as was the
case.
XVI. THE ALGENTIANA, A.D. 300.
This aqueduct is said by some to be only a branch from the Aqua Marcia
from the _castellum_ or _piscina_ at the Porta S. Lorenzo, to the Thermæ
of Diocletian, and to have been made by him. Considerable remains of the
large _piscina_ for these Thermæ were found when the railway station
was built, a plan and section of it was preserved by Visconti; it was
not destroyed, but was built over and effectually hidden. The aqueduct
was continued, A.D. 330, by Constantine to his Thermæ on the Quirinal,
now in the Colonna gardens. Others say that the Algentiana comes from
the Mount Algidus, near Tusculum. In the Campagna between Frascati and
Rome, there are remains of large reservoirs or _castella aquarum_ of the
third century, which do not appear to belong to any of the aqueducts
hitherto described. They are usually said to be only reservoirs for
the supply of the adjacent fields; but they are all on the highest
points, and it is difficult to see how the water was conveyed to them.
There appears to be a regular line of them, not indeed a straight line,
(the nature of the country would not admit of that,) but still a line
of them at comparatively short intervals, always within sight of one
another. It seems probable that the Aqua Algentiana was brought in a
subterranean channel or _specus_ from the great reservoir at Tusculum,
which is on very high ground, and that the water was permitted to run
into these reservoirs at frequent intervals, instead of being carried
on an arcade across the country, as had been done in the case of the
earlier aqueducts. It is beyond dispute that the ancient Romans were
well acquainted with the principle of the syphon, and that they were
quite aware that water will rise to its level after a very considerable
distance: they may have therefore thought it expedient in this aqueduct
to avail themselves of that principle. It is difficult to explain how
water could be supplied to these numerous high reservoirs in any other
manner.
XVII. AQUA CRABRA, AND MARRANA, A.D. 1124.
This stream was brought into Rome in the bed or foss of the river Almo
(Flumen Almonis), mentioned in the Regionary Catalogue as in Regio I.,
and not otherwise accounted for in this enumeration. The water now comes
from the Marrana, which has its source near Marino, and from the Aqua
Crabra, which comes from Rocca di Papa, near the lake of Albano, some
miles further up the hill; the waters of these two streams are united
before a part of them is carried through the tunnel of the Aqua Julia to
a point of junction with the bed of one of the many branches of the small
river Almo. The Almo itself comes also from the hill of Marino, but from
a different part of it, and is divided into many branches when it arrives
on the low ground of the Campagna. One of these was made use of for this
mill-stream, a canal being carried in banks of clay in straight lines,
where the old bed of the river passed through low ground, and had been
therefore liable to floods; but this old bed or foss was used, to save
expense, where it passed through higher ground in its old winding course.
Originally that part of the branch which passes through Rome was
alternately wet and dry, as many of the other branches are, and was
liable to floods after heavy rains. The main branch of the Almo turns
off to the south near the Torre Fiscale, following nearly the same line
as the cross-road from the Via Appia Nova to the Via Appia Antiqua, and
passing under this road twice. In this part of its course it is generally
dry in dry weather; but when it arrives at the head of the valley of
the Caffarella, several other springs that never fail run into this old
deep foss. One comes from near the villa of the Quintilii, another is
called the fountain of Egeria, a third the Aqua Santa, from its medicinal
qualities. There is a bath-house built over that spring. The original
springs on the hill of Marino bring little water in dry weather, not more
than sufficient to supply ponds near to them for the cattle; but, in wet
weather, the water runs off in the old deep winding foss, which also
drains all that part of the country.
The sources of the Marrana are about a mile above Marino, and nearly
three miles from Albano; they are in a long, narrow, deep valley in the
rocks, and the water gushes out in several places at short intervals on
both sides of this valley, which continues on under the rock on which the
small town of Marino is built. Close under the town is a tall medieval
tower, and at the foot of this is a _piscina_ of rude early character,
the lower chamber of which is still full of water. A _specus_ cut in the
rock as a tunnel is also visible at this point. On the side of the valley
opposite to the town are the splendid ancient quarries of _peperino_,
called by Vitruvius _lapis Albanus_, because Marino was in the district
of Alba Longa. The stream flows on in the same deep valley, winding down
the hill, and, at the foot of it, the Aqua Crabra, coming from Rocca di
Papa, is united with it shortly before it is crossed by the bridge on the
road to Grotta Ferrata, ten miles from Rome and near the tunnel through
which flows part of the united water, the main body going on straight to
the river Anio; the part which is carried through the tunnel turns at a
sharp angle to the left, or west, towards Rome. At each end of the tunnel
is a loch of early character, partly cut in the rock and partly built
of travertine, with the grooves of flood-gates. Over the exit from the
tunnel is a piece of old wall faced with _Opus Reticulatum_, of the same
rude early character as that of the Aqua Julia.
After the water emerges from the tunnel, it passes in a deep bed to a
bridge over the stream of the Marrana, near the _piscinæ_, six miles from
Rome. At this point the deep foss of the river Almo is close to it. This
is dry in dry weather, but has abundance of water in wet weather, and
here the foss is dammed across; this appears to have been done originally
to effect a junction with the water of the Marrana, which from this point
flows in the foss of one of the many branches of the Almo that intersect
the Campagna in this part. This mountain-stream is a very uncertain one;
sometimes the deep foss is full of water, flowing at the rate of five or
six miles an hour, at other times it is dry. Numerous winding streams
are collected into one at the head of the valley of the Caffarella, near
the church of S. Urbano. Here it passes through swampy ground at a place
called Aqua Santa, on the cross-road from the Via Appia Nova to the Via
Appia Antiqua; here also several springs fall into the deep bed, one
of which is miscalled the fountain of Egeria[193]. In dry weather this
branch of the river Almo appears to begin here, and from thence to the
mouth of this branch near S. Paul’s, mentioned by S. Gregory as the Almo,
the water never fails. All the other branches are deep, dry fosses after
dry weather, and the branch that now flows through Rome must originally
have been frequently dry, and at other times liable to floods[194].
To remedy this evil, a branch was made from the stream, consisting of
the Marrana and Aqua Crabra united, which never fails; and, in those
parts where the water passes over low ground liable to be flooded, it
is carried in a bank of clay covered with sand, and planted with canes.
In such a bank it is carried from near the ford in the natural bed of
the river at Roma Vecchia to the Torre Fiscale. Between these two points
there is a loch with a flood-gate and a lasher, over which the water
falls into one of the deep beds or fosses of the Almo; but this deep bed
of a mountain-stream has no other beginning than this same stream, here
raised in a bank of clay, into which the water of the Marrana has been
turned. In other parts where the ground is high, and consequently the
water is below the level of the ground, it follows its ancient, natural,
winding course in a deep foss. This is the case both near the original
point of junction before reaching the ford at Roma Vecchia, again after
passing the Porta Furba, and again under the walls of Rome near the
Lateran. From Roma Vecchia, passing by the Torre Fiscale to the Porta
Furba, it is carried in a bank of clay many feet above the level of the
meadows; but after passing the Porta Furba, it again falls into the old
deep foss for about a mile at the foot of the Claudian arcade, winding
about sometimes on one side, sometimes on the other, then near to a part
of the road to Frascati. For the last half-mile to the Porta S. Giovanni,
this road is modern on a large bank of earth across the valley or great
foss outside the Wall of Aurelian, and for most part of this line the
Marrana is carried in a small bank of clay against the side of the larger
bank of the road; but before it reaches Rome it falls again, that is, the
earth rises on the terrace under the wall, and the Marrana falls into the
old deep bed near the Porta Asinaria, after passing through two mills
built on bridges, one on the line of the old Via Asinaria, the other of
the old Via Lateranensis.
This small stream enters Rome under the Porta Metronia, which is built
on a bridge over it[195]. This bridge has a brick arch of the time
of the early Empire, partly concealed by a medieval arch in front of
it. Shortly after entering Rome the stream passes at the north end of
what is now the nursery-ground of the city, called Orto Botanico, and
under a bridge on which another mill is built; by the side of it is the
road into that large garden, known to have been that of Crassipes, the
son-in-law of Cicero, who mentions in one of his letters a flood of this
stream carrying wooden shops from the bank in front of it to the Piscina
Publica[196].
This is exactly the direction that the stream takes, as it turns at a
sharp angle to the north directly after crossing the Via Appia, and
passes close to the Piscina Publica; while the Tiber flows from north
to south, and a flood of that river would have carried the shops the
other way (if it reached that level at all). There is another mill near
the angle on the Via Appia. The stream then passes along a curve at the
southern end of the Circus Maximus, (washing the foot of a lime-kiln,)
then under the slope of the Aventine and through the gas-works on the
site of the Carceres of the Circus, then underground and through another
mill in the Via della Marrana near the Bocca della Verità. The eighth and
last mill is on the bank of the Tiber, and is built over the mouth of the
stream, the back of the building resting on the old tufa wall, called
the Pulchrum Littus of the Kings, in which an aperture was left for the
Almo when that wall was built. The front of the mill is built on medieval
arches standing in the bed of the Tiber.
This alteration of the bed of the Almo may have been made at an early
period, of which we have no record, and restored to use in 1124, under
Pope Calixtus II., or it may have been entirely made out of the remains
of the old aqueducts at that time. We have distinct records of the work
done then; but in one of these the expression used is _reduxit_, that
is, he “led again” the water from the old arches. In any case, a great
benefit to the city was made at that time, and the account of it fairly
belongs to the history of the aqueducts, from which it was made. The
following account of it is given by the Cardinal of Arragon, in the time
of Pope Calixtus II., A.D. 1124:—
“He (the Pope) also brought water from the ancient arches, and
conducted it to the Porta Lateranensis, where he formed a
lake to receive it, for watering horses. He also built several
mills on the line of the same stream of water, and planted many
vines and fruit-trees round the borders of this lake with great
care[197].”
Another writer of the same period, called Pandolph of Pisa, relates the
same thing:—
“He _reconducted_ a stream of water into the city, and made
mills, with vines near a lake[198].”
The ancient aqueduct which was made use of for the purpose was the Julia
(V.), (which see,) and the ancient arches mentioned probably mean the
tunnel through which the water of the Aqua Crabra and the Marrana united
is brought. Its course has been already described, the great reservoir
or lake (_lacus_) opposite to the Porta Lateranensis is very distinctly
visible in the vineyard by the side of the stream, between that and the
Aurelian wall. It is still swampy ground, and is planted with canes;
when these are cut at the end of the month of January, it can be clearly
seen, and the remains of the lake intercept the path on the bank of the
stream. This reservoir might be restored to use with great advantage to
the neighbourhood, and at little expense.