FACSIMILE FROM THE MANUSCRIPT AT MONTE CASSINO[50].
I. [The Augustan branch] is joined to it [the Aqua Appia] at the old Specus [or old Spes (?), temple of Hope], in the border of the Torquatian gardens[53]. I. 5.
II. [The three, Marcia, Tepula, Julia] there emerge again; first, however, part (of the water) intercepted from the Julia is poured at the old Specus (or at the old temple of Spes[54]), and so into the reservoirs on the Cœlian Hill, near the temple of the divine Claudius. I. 19.
III. First, however, the Claudia transfers part of its [water] into the old Specus [or at the temple of Spes], on the arches called Neronian[55]. I. 20.
IV. But the direct conduit [of the Marcia, &c.], passing by the old Specus (?) of the Appia (at a higher level, or following the old Hope?)[56], coming within the Porta Esquilina, [the water] is drawn off in the high streams through the City. I. 21.
V. [The Aqua Appia], however, at the Gemelli[57], which place is below the old Specus [or below the old temple of Hope (?)], is joined with the Augustan branch. II. 64.
VI. But after the Emperor Nero had carried the Claudian (water), which he diverted, on arched work to the temple of Claudius [or the Claudium], at the specus[58] (or at the Temple of Hope?), that it might be distributed thence. II. 76.
VII. By which many waters, especially the Marcia, being supplied in great abundance, are conducted from the specus[59] (or from the temple of Hope?) on to the Aventine. II. 87.
“At the time when this disaster happened, Caius Horatius and Titus Menenius were in the Consulship. Menenius was immediately sent against the Etruscans, elated with their victory. He also was worsted in battle, and the enemy took possession of the Janiculum; nor would the City, which besides the war was distressed also by scarcity, have escaped a siege (the Etruscans having passed the Tiber), had not the Consul Horatius been recalled from the country of the Volscians. So near indeed did the enemy approach to the walls, that first the engagement was at the temple of Spes, in which little was gained on either side; again at the Porta Collina, in which the Romans gained some small advantage, and this, though far from decisive, yet by restoring to the soldiers their former courage, qualified them the better to contend with the enemy in future[60].”
“At Rome a dreadful fire raged during two nights and one day; everything between the Salinæ (or salt wharf) and the Porta Carmentalis was levelled to the ground, as were the Æquimælian and the Jugarian streets. The fire catching the temples of Fortuna, of mater Matuta and of Spes, on the outside of the gate, and spreading to a vast extent, consumed a great number of buildings, both religious and private[61].”
“After this, in pursuance of a decree of the Senate, and an order of the people, an assembly of election was held by the city prætor, in which were created five commissioners for repairing the walls and towers, and two sets of triumvirs: one to search for the effects belonging to the temples, to register the offerings; the other to repair the temples of Fortuna and mater Matuta within the Porta Carmentalis, and likewise that of Spes on the outside of the gate, which had been consumed by fire the year before[62].”
“He agreed with contractors for building a theatre near the Temple of Apollo, and for embellishing the Temple of Jupiter in the Capitol, and the columns around it; he also removed from those columns the statues that stood incommodiously before them, and took down the shields and military ensigns of all sorts which were hung upon them. Marcus Fulvius made contracts for more numerous and more useful works—a haven on the Tiber, and piers for a bridge across it, on which piers Publius Scipio Africanus and Lucius Mummius, censors, many years after, caused the arches to be erected; a court of justice behind the new bankers’ houses, and a fish-market, surrounded with shops for private sales; also a forum and porticus, on the outside of the Porta Trigemina; another porticus behind the dockyard, and one at the Temple of Hercules; also a temple of Apollo Medicus, behind that of Spes, near the bank of the Tiber[63].”
It will be observed that all these passages apply to the well-known Temple of Spes near the bank of the Tiber, of which there are considerable remains now in the church of S. Nicolas in Carcere, and do not apply to a Temple of Spes at the Porta Maggiore.
The word specus is used by Vitruvius in the sense of a covered water-course:—
“But if there should be mounds in the middle between the walls and the fountain-head, it must be so contrived that the water-channel (specus) be dug under the earth, and poised on the top[64].”
And at a later period by Hirtius:—
“Alexandria is almost wholly undermined with water-courses, and has a specus extending to the Nile, by which water is conveyed into private houses[65].”
“127 years afterwards, that is, from the building of Rome 608 years, when Servius Sulpicius Galba and Aurelius Cotta were consuls, as the aqueducts or conduits (ductus) of the Appian and Anio were much decayed by age, (and also intercepted fraudulently for private purposes,) the business of repairing and reclaiming the said aqueducts was entrusted by the senate to Marcius, who was then acting as Prætor. And because the increase of the population of the city seemed to demand a more ample supply of water, instructions were given to him by the senate that he should carefully examine how far there were other streams which he might be able to bring into the city[66].
“He therefore restored the two old conduits, and introduced a third, which he caused to be erected with ‘squared stones,’ and larger aqueducts, and carried through them the water which he had obtained for the public service[67]. Hence it received the name of the ‘Marcian’ from himself, as the author of it.
“The Aqua Marcia has its origin on the Via Valeria at the thirty-sixth milestone, three miles off in the diverticulum (or cross-road), on the right-hand to those going from Rome. On the road to Sublacum, now called Subiaco (Via Sublacensis) also (which was paved for the first time under the Emperor Nero), at the thirty-eighth milestone, for the space of two hundred paces on the left-hand side the water lies like a pond, bubbling up in innumerable springs from beneath the stony hollows, and is very green in colour.
“The length of the course from its head to the city is 61 miles, 710 paces;—by an underground channel 54 miles, 247½ paces, on structure above ground 7 miles, 463 paces. Out of this, in many parts away from the city, in the upper part of the valleys, it is carried on arched substructure for 473 paces; nearer the city, from the seventh milestone, on a substructure for 528 paces. In the rest of the work it is carried on an arcade for 6 miles, 472 paces[68].”
“The Marcian ranks fifth in height, and is at its head even in level with the Claudian[69].”
“In the year of the building of the city, 719 (i.e. B.C. 44), Agrippa repaired the three aqueducts—the Appian, the Anio Vetus, and Marcian—and took care to supply the city with many fountains[70].”
“[Temp. Nervæ, (A.D. 96)] the Marcian having been enlarged was carried across from the Cœlian [i.e. its specus] to the Aventine[71].”
“In the year 627,” writes Frontinus, “after the building of the city, when Plautius Hypsæus and Fulvius Flaccus were consuls, the censors, Cneius Servilius Cæpio and Lucius Cassius Longinus, took care to bring into Rome and the Capitol the stream called the Tepulan, from the Lucullan Fields (which some call the Tusculan[72]).
“The Tepula has its source on the Via Latina at the tenth milestone, two miles off on the right of those going from Rome. Thence it was brought by a separate channel into the city[73].”
“Afterwards Marcus Agrippa collected the natural waters of another stream, at 12 miles from the city on the Via Latina, (2 miles off on the right of those going from Rome,) and so intercepted the stream of the Tepula. To the newly-acquired water the name of Julia was given, from the finder of it; nevertheless the distribution was so divided that the name of Tepula was retained[74].
“The course of the Julia runs for the length of 15 miles, 426½ yards. In work above ground 7 miles; out of this in parts nearest to the city from the seventh milestone (it is carried) on a substructure for 528 yards; the rest on arched work for 6 miles, 472 yards[75].”
“Of these [Aquæ], six within the seventh mile, on the Via Latina, are taken up into covered piscinæ, where, as though breathing again after their course, they deposit mud. The Julia, the Marcia, and the Tepula, are joined there; of these, the Tepula, (which had been intercepted, and joined to the stream of the Julia,) now receives from the reservoir of the same Julia its proper quantity, and flows out in its own channel, and under its own name.
“These three are carried from the reservoirs on the same arcade.
“The highest of them is the Julia, lower the Tepula, then the Marcia. These come down towards the Viminal, running together beneath the ground, on the same level as the Collis Viminalis, as far as the gate. There they again emerge.
“First, however, a part of the Julia is, at the Spes Vetus, taken out and distributed in the castella on the Cœlian Hill; but the Marcia, after the Pallantian Gardens, throws off part of its water into a stream called the Herculanean. This conduit through the Cœlian, being of no use for the houses on the hill because at too low a level, comes to an end above the Porta Capena[76].”
To this point, Frontinus tells us, the three aqueducts tend[77], while from this they are carried on the same arcade into Rome. The ruins of these remain visible. Some of them are situated a little way off the south side of the Via Latina, others on the east side of the Via Appia Nova. Of these, two belonging to the Claudia and Anio Novus are subterranean, and are now only to be distinguished as mounds of earth, looking like tumuli. Others are above ground, near that part of the Via Latina [now the road to Frascati and Tusculum], and close to the Torre di mezza via, or half-way house from Rome to Frascati, just beyond the sixth milestone of the modern road. Others are at or near the Villa of the time of Hadrian, called Sette Bassi (which is supposed to be a corruption of Septimius Bassus), near the same point. All of these are between seven and eight miles from the City; they are the chief landmarks in tracing the course of the three aqueducts now to be explained, and each of the three comes from its own separate source. The Marcia, the lowest on the arcade, has its origin at the greatest distance from Rome. The Tepula and Julia have their sources comparatively close to the city. The Marcia takes its rise from the Simbrivine Hills, as far removed beyond Tibur to the east as Tibur is from the city, while the latter two find their way from springs in the volcanic region around the lake of Albano.
The source of the Marcia is plainly visible, the exact description of Frontinus pointing to the spot without leaving room for doubt. In one of the numerous little valleys which run down on the north side of the River Anio, feeding this stream with their rivulets, the Marcian has its rise. The lake of S. Lucia[78] in that valley is so called from a small village situated some distance up the slope; along the bottom of this valley the Via Valeria passes. This lake is usually, but erroneously, considered as the source of the Aqua Marcia.
The exact position of the source is about two miles from the village of Marano, but on the other side of the river, on the right of the valley to one looking towards the mountains, and there are still at times pools of water forming here from the springs which emanate from the overhanging hills. The water now falls into two or three rivulets, which run at the bottom of the valley into the river Anio.
The aqueduct, however, when it reached the high road from Rome to Subiaco, along the north bank of the Anio, turned abruptly to the west, followed the course of the road back towards the city, chiefly passing the further or hill side of it, but winding somewhat according to the nature of the ground. After following the road for some seven or eight miles, it crossed the river (close to the monastery of S. Cosimato) and then pursued for some six or seven miles the southern or right bank of the river Anio. Here, at a spot scarcely more than a mile from Tivoli (Tibur), the course of the aqueduct left the line of the river, and wound its way in a south-westerly direction towards the piscinæ before referred to; at times on a substructure, and in a few places, where the valleys were deep, on arches, but for by far the greater distance beneath the surface.
The line of the Marcia can be clearly traced along its whole length. The principal source, called Acqua Serena, is a beautiful spring gushing out from the mountain under the present carriage-road, about seven miles and a-half before arriving at Subiaco, clear as crystal and very abundant; it forms a small lake in the valley, and fully realizes the description of Martial. The old specus, which had long been concealed by being a foot or two under water and overgrown with weeds, was brought to light in 1869 by the engineer of the Aqua Marcia Pia, in making his new works for the restoration of this beautiful water to use in Rome. He drained the lake a little, and by that means made the specus visible[79]: this specus is then carried to the cliff of the valley of the Anio (into which the water from the small lake falls), and then follows the course of the valley and the river, until it comes to the monastery of S. Cosimato, a mile from Vico-Varo: here it crosses the river on an arcade of brick. It there leaves the present road, and then is carried in the cliff on the other side of the river until it arrives within two miles of Tivoli, where it again crosses the river (here a deep ravine) on a fine arcade parallel to that of the Anio Novus, and at a very short distance from it. There are very fine and picturesque ruins of both these arcades in the valley called the Valley of the Arches. It then continued in the cliff by the side of the present road, which is on a ledge of the rock or hill overlooking the Anio, as far as the old town of Tibur and the Cascades, behind the present town of Tivoli: to avoid these it follows a serpentine course, winding round the end of the hill, and has a fine reservoir about half a mile beyond the town, on the side towards Rome, below the level of the Promenade of Carciano, by the side of which are considerable remains of a large reservoir or piscina, with the specus running into it and from it. This large building is divided down the middle by an arcade, into two nearly equal parts. Some of it is faced with Opus Reticulatum of a peculiar pattern. On the exterior, there are remains of niches and fountains, a villa of some importance having been built at this spot to take advantage of the abundant supply of excellent water[80]. The specus then runs near the cliff below the level of the road to another extensive reservoir and piscina about a mile further on. There are considerable remains of a large building erected on a steep slope just under the cliff, with no upper wall, as the cliff itself supplied its place; but there is on the lower side a fine wall of considerable extent and height, built of large square or oblong stones of the construction called Cyclopean Masonry[81], in this instance differing little from that of the Walls of the Kings in Rome, except that the stones are rather larger, the building-material being not tufa, but a kind of calcareous stone of the country, dug on the spot. This wall has been supposed to be a portion of the fortifications of the ancient city of Tibur, but for this there does not appear to be the slightest evidence or probability. It is simply the natural construction of the material at hand, and therefore the cheapest wall that could be built for the purpose. No cement is used, because none was required; these large blocks of stone require none, and some chippings are used to fill up interstices, as usual when no cement is used. Again the wall turns the corner at both ends; it is not part of a large wall but is complete in itself, as the facing of one side of the reservoir and filtering-place, the interior of which is built of the usual concrete of rough stone and mortar, and lined with cement of the kind which holds water, Opus Signinum, used for all the aqueducts. The end is faced with Opus Reticulatum, and there are remains of niches against the wall at intervals. It was also more ornamented, because it was intended to be the one seen chiefly; the other side, being near the edge of a precipice, would only appear from a distance, and the large stones were therefore more effective in that situation. There is no reason to doubt that the whole was built together at the time that the Marcian Aqueduct was made, and it was probably restored by Augustus. It may be doubtful whether some caves in the cliff, which formed part of the reservoir, were natural or were cut, and the stone dug out from them. It is altogether a very picturesque and interesting structure. There may be a question also whether there was not a branch from this reservoir to the Villa of Hadrian at the foot of the hill, perhaps a mile lower down.
The specus of the Marcia is visible at the Ponte di S. Antonio over that of the Anio Vetus; and again, but alone, at the Ponte di S. Pietro, and it passes the Ponte Lupo with the Anio Novus, Claudia and Anio Vetus. It then continues, chiefly underground, to the great piscinæ before mentioned, and thence on the arcade into Rome.
After reaching the City, the branch mentioned by Frontinus, c. 87, as being carried across the valley from the Cœlian to the Aventine in the time of Nerva, seems to be the one found during the excavation in 1868, passing over the Porta Capena at a higher level than the Appia, but still at a much lower level than the lofty arcade of Trajan, of which only the bases of the series of piers crossing the valley now remain. The aqueducts following this line had all to cross the Via Appia, here a foss-way, on the arch of the Porta Capena. This southern branch of the Aqua Marcia is probably the one that can be traced along the side of the cliff of the Pseudo-Aventine, after it had been repaired and brought again into use, for it must be remembered that at one time, as Frontinus says, it ended at the Porta Capena.
The conduit and arcade were rebuilt by Augustus, as recorded on the inscription on his arch at the Porta S. Lorenzo, and in the sixth decree of the Senate, on the subject of the aqueducts. This branch arcade of Augustus is there expressly named as distinct from the others, all needing repairs at the time of this edict. The consuls are charged to see to “the repairs, at the expense of the city, of the streams, conduits, and arches, of the Julia, Marcia, Tepula, Anio; also of those streams and arcades which Augustus Cæsar had rebuilt.”
A branch of the Marcian aqueduct was carried along the agger into the Prætorian Camp. Some leaden pipes were found there in 1742, with an inscription upon them, recording that they were of the time of the Emperor Macrinus (A.D. 217). This probably indicates either a renewal of the pipes, or an additional supply of water. The garrison in that camp was twelve thousand men, and a large supply of water must have been required for their use[82].
The excellent qualities of the Marcian water are mentioned by several of the classical authors, and were celebrated for a long period; they were known in England in the time of Shakespeare, as appears from the following passage in Coriolanus, Act ii. Sc. 3—
There is a slight anachronism here. Coriolanus lived in B.C. 489, and the Marcian aqueduct was constructed in B.C. 145, more than three hundred years after his death. Marcius Censorinus also, who was twice Censor (the only Roman who filled that office twice), lived B.C. 294.
In the thirteenth century, the church of S. Bibiana is incidentally mentioned as being near the arcade of the Marcian aqueduct[83]. In some excavations made in the year 1871, a portion of the Marcian arcade, built of the usual large squared stones, was shewn, passing under some high ground to the north of the Porta Maggiore, within the wall of Aurelian, in a direction to join the bank on which that wall is built, and passing between the Minerva Medica and the wall in that part. This is very near the church of S. Bibiana.
The sources of the Tepula and the Julia are in the valleys on either side of the promontory on which the modern town of Marino stands, the ancient Castrimœnium (under the village of Rocca di Papa). That of the Julia is on the south side, and almost close under the crater now the Alban Lake. The Tepula rises near the bottom of the valley which comes down from the hills in the neighbourhood of Grottaferrata, and along which the Via Latina passes. This lies somewhat nearer to Rome than the source of the Julia; but the Julia joined it before it had advanced far, and thus the expression of Frontinus, “Marcus Agrippa intercepted the Tepula[84],” is explained. The waters, therefore, flow into the same series of reservoirs and cisterns which received the Marcian after they enter Rome.
Under the account of the Julia, the Aqua Crabra is mentioned. This is the little stream into which the water of the Julia and Tepula falls; which is united at the foot of the hill on which the town of Marino stands, to another stream called the Marrana, and the united water is now generally called by the latter name only[85]. Frontinus mentions several reasons why it was not made use of for supplying the city with water; but it was brought into Rome in the twelfth century as a small mill-stream.
Frontinus also says that the Tepula had its source at ten miles from Rome on the Via Latina, with two more miles to the right on a cross-road[86]. Ten miles on the Via Latina brings us near to Tusculum, at the tenth mile is the Casino de Ciampino, from which starts a cross-road to the right; and at two miles from that point we arrive at the springs called Fontanaccio, before reaching Grotta Ferrata, but close under that village. It follows that the source of the Tepula was at this place, now called Fontanaccio. The spring comes out under a cliff of the rock of lava near the road, and has a modern washing-cistern in front of it; but behind this the ancient work can be seen, with openings into a reservoir in the cliff. This is probably contemporaneous with the time that the conduit of the Tepula was made. The supply of water is small, but of good quality.
As the Aqua Tepula supplied only the Regiones in the northern part of the city, it seems to have passed into the castellum, the remains of which may still be seen in the city wall near the Porta S. Lorenzo, evidently built upon an old agger before the Aurelian wall was erected[87]. It, however, has been a house as well, the lower part only being used as the reservoir for the water, and the upper part, which is large and important, for chambers. The front of this house, or castellum aquæ, still forms part of the city wall. It has been much disfigured, and the old drains walled up during the restorations (!) of 1869.
On the level of the first floor, in which is part of the reservoir, is a row of corbels to carry a wooden gallery or hourd, probably an external passage for the use of the Aquarii, behind which the specus runs at the same level. Immediately above the line of the corbels which carried the floor of the gallery or balcony, is a row of large arches; but these are merely the arches of construction found in most walls of the period. At the south end of this line of corbels, which mark the extent of the castellum in that direction, there is an angle, and the wall recedes a few feet. In this angle is the specus, corresponding in form and dimensions with that of the Aqua Tepula in other parts; it can be seen entering into the reservoir behind the line of corbels. Within the wall are the usual marks of a reservoir of water: the tartar deposit remains visible in the corners of the chambers cut through by the wall of Aurelian, or by the engineers of the Acqua Felice, whose specus runs behind it on the bank within the wall which formed the front of the house. The specus of the Acqua Felice is here at rather a higher level than the Marcian arcade, with the three specus upon it, although at the “Sette Bassi,” five miles from Rome, and near the piscinæ, it is at a lower level. On the bank just above the level of the ground are the water-drains (hidden by the restorers in 1869) for carrying off the superfluous water into a large subterranean drain which runs under the gateway, and which is still in use for purposes of irrigation.
Frontinus states that the source of the Julia was at twelve miles on the Via Latina, with two more miles added on a cross-road to the right[88]. The twelfth mile is at Frascati; from thence, by a cross-road to the right, we arrive at the bridge of the Squaricarelli, and at the copious springs called the Fontanile, exactly two miles from the starting-point at Frascati. This must, therefore, be the source of the Aqua Julia.
The swampy ground in which the source of the Angelosa or Aqua Julia is found, is full of springs, like the Lucullan fields, from which flow the Appia and the Virgo, and from it run also the streams called di Monte Fiore and la Marrana di Marino.
This ground is on a high level on the Monte Fiore e dell Aglio (the Mons Algidus of the ancients), or “The hill of flowers or of garlic;” and the springs come from the gardens of the modern Villa Aldobrandini, at Frascati. Canina cleared out the ancient specus, which had a curved vault, almost oval (a capanna).
This source of the Julia is on the left-hand side of the road from Grotta Ferrata to Marino, about a mile above the former, and nearly the same distance below the latter. The water gushes out from the foot of the rock and passes under the road to a lavacrum, or washing-place, at a lower level on the opposite side of the road, and then falls into the Aqua Crabra, which passes at the foot of the cliff many feet lower down. A part of the water of the Julia, before it goes into the lavacrum, is carried to the right in a specus to Grotta Ferrata. This is ancient, but has been restored to use, so that it looks modern. Below Grotta Ferrata, the specus has been destroyed in many parts; but remains of it may be seen close to the ancient fortified villages called Pagus Lemonius (on the maps Castellaccio, a small castle). It is ten miles on a branch of the ancient Via Latina, and between the present roads to Frascati and Grotta Ferrata. In a part of the fortifications of this village is a castellum aquæ, or reservoir of the Julia, and near it part of the specus, on an arcade on the brow of the hill. This specus is built of rough stone, and faced with a rude early kind of Opus Reticulatum, more rude indeed than might have been expected at its date (B.C. 34), and not nearly such good work as the Muro Torto, but more like the Emporium. The reservoir is of the same character, but part of the specus in the fortifications is carried on brick arches which agree with that date; the brickwork is not of the time of Nero, to whom it has been attributed. A specus of rough stone follows the line of the hill to the Marrana, after the junction of that stream with the Aqua Crabra, close to the point where the water from that stream enters a tunnel of the Aqua Julia. After it emerges from this tunnel, it arrives at the castellum or piscina in which the water of the Julia was received before it was carried on the Marcian arcade. This piscina is about two miles nearer to Rome, close to the point of junction between the roads to Frascati and Marino, through Grotta Ferrata, and near to the other piscinæ.
Frontinus says that the Aqua Crabra flowed past the head of the Julia, but was excluded from it by Agrippa[89]. We find this stream coming from that part of the hill on which the village called Rocca di Papa is situated, passing near the head of the Julia at Fontanile, now Angelosa, and sometimes mixing with the springs there. It has one of its sources in the grounds of the Villa Torlonia, at Frascati. All these three streams now fall into the river Anio.
Near Rocca di Papa an arcade, or bridge of ten arches, of silex or flint, covered with brick, passes over the Aqua Crabra to carry some aqueduct, probably a part of the Julia. This arcade is called Arcioni, [‘the arches.’]
There are some remains of another reservoir within the wall of Rome, on the bank between this and the Porta di S. Lorenzo, which seems to have belonged to the Julia: the specus of the Marcia, with that of the Tepula and remains of that of the Julia over it, are visible on an arcade a little beyond, close to the gate. The lower part of a fine brick wall with bold buttresses, of the usual character of a piscina or castellum aquæ, are visible, and this faces the present Wall of Rome, almost touching it, so that this has been built since the piscina, but that not being exactly in the same line it could not be used. The piscina of the Tepula being on the outer side of the bank or mœnia came into the line of defence of Aurelian, and was used as part of his wall; that of the Julia, being on the inner side of the bank, was too much within the line to be used.
The Castellum Aquæ Juliæ, or chief reservoir of the Julian Aqueduct, is usually, but erroneously, said to have been the one situated on high ground near the church of S. Maria Maggiore, where the picturesque ruins stand, usually called the “Trophies of Marius,” because those trophies were hung under two of the arches there, until they were removed to the Capitol. A lofty arcade carrying a specus at a high level passes across the valley, from the reservoir near the Porta S. Lorenzo to this point. This arcade is of the first century, built of the fine brickwork usual at that period, and agrees with the time of Frontinus; but the only aqueduct that was high enough to have carried water to that spot was the Anio Novus.
This great reservoir was rebuilt by Alexander Severus, and called a Nymphæum, being given as such on one of his coins. This name is rather a vague one; but it is evident, from some excavations made in 1871, that there were extensive thermæ of the Emperors of the third century near this place.
From this lofty reservoir the distributing channels may be seen branching off in different directions, one going to the Thermæ of Titus, towards the reservoir called the Sette Sale, another going in a different direction.
This Nymphæum (?) is on lower ground than the outer wall, though still on ground so high that the only water that could reach it was that of the Claudia and Anio Novus, of which part of the arcade remains between it and the reservoir on the high bank. From that point the ground descends gradually and gently along the line of the agger of Servius Tullius either way, and still more towards the interior of the city. The aqueduct, therefore, could not pass underground and then emerge in this part. The Porta Esquilina of the inner wall was on the same level, or nearly so. The Porta Tiburtina of the inner wall was near the thermæ of Diocletian, with a gradual and gentle descent to it along the line of the agger. The only possible explanation of the text of Frontinus is that the same names of the gates in the inner wall were applied to those in the outer wall on the same roads.
A piece of leaden pipe, with an inscription upon it, was found at the Porta S. Lorenzo, which gives the names of Dolabella and Silanus as Consuls; this fixes the date at A.D. 10, and shews that the Marcian water was conveyed in leaden pipes at that point in the time of Augustus. The stone specus was carried over the gate, as we see by the remains of it in the wall, and the inscription upon it recording repairs by Augustus. The one upon the leaden pipe is given by Gruter[90].
Another leaden pipe was found by Panvinius on the site of the Prætorian Camp, with an inscription, given by Gruter[91], which records that it conveyed the Marcian water to that point.
Three aqueducts are mentioned in other inscriptions found during the excavations near the railway station in 1869[92]; the three aqueducts intended can hardly be other than the Marcia, Tepula, and Julia. The upper one only was excavated; but if the noble Roman princes who conducted this excavation had dug a little deeper, they would probably have found the other two under the one that they had discovered. These three specus must have been carried along and in the agger of Servius Tullius.
To reach that part of it on the side of which these cippi are found, they probably went along the side of the road that passed on the south side of the Prætorian Camp, on which was the gate called Porta Chiusa. Close to this gate remains of a large reservoir were found in the researches of 1869 on the bank, with the Wall of Rome carried right across it; but this part of the wall is medieval, built of old materials, and it is probable that, originally, the front wall of this reservoir was included as part of the wall of the city, in the same manner as that of the Tepula near the Porta S. Lorenzo. This reservoir, with the Porta Chiusa by the side of it, and the road from it to the agger, at the place where the cippi were found, is now in the garden of the Baron Grazioli.
This Aqueduct was made by Marcus Vipsanius Agrippa to supply water to his Thermæ, on the south side of the Pantheon, which was the hall of entrance to them.
Frontinus writes:—
“The same (M. Agrippa) when he had been consul for the third time, and when C. Sentius and Quintus Lucretius were consuls, that is, thirteen years after he had brought down the Julia, he brought the ‘Virgo’ also, the water of which was collected in the Lucullan fields[93].
“The Virgo begins on the Via Collatia, at the eighth milestone, in some marshy places: a cemented wall [signino[94] circumjecto] being placed round it, to retain the bubbling waters; the source was increased by many other additional supplies. It comes for a length of 14 miles and 105 paces. Out of this,—by a subterranean stream 12 miles, 865 paces; above ground for 1 mile, 240 paces, of which it runs on a substructure in several places for a distance altogether of 540 paces; on arched work 700 paces. The channels of the additional supplies of the subterranean stream make 1 mile, 405 paces[95].”
The Virgo has no reservoir, i.e. Piscina ... “The arches of the Virgo have their commencement beneath the Lucilian (or Lucullan?) gardens. They end in the Campus Martius, along the front of the Septa[96].”
The Virgo was the seventh in height as to level (c. 18).
The road now called Via Collatia, or Collatina, where the Aqua Virgo has its origin, is between the present roads to Tivoli and Palestrina; it turns off to the left or north of the highway now called Via Prænestina, just beyond the ruins called Torre de’ Scavi or de’ Schiavi, about three miles from the city. But this is an alteration; the old road from Rome to this point in a foss-way may be traced behind the tower in the meadows, with the subterranean aqueduct running under and in the southern bank of it, as traced by the respirators or ventilating shafts. There are remains of very ancient tombs at intervals all along the line of this old road, which goes straight towards a postern-gate midway between the Porta Maggiore and the Porta di S. Lorenzo. This must be the Via Collatia of Frontinus.
Close to this road, at eight miles from Rome, near the ruins of Collatia, there are several springs in marshy ground, from which the water is collected in a series of reservoirs, just below the level of the ground, the vaults over them being sometimes above ground; from these small reservoirs separate short conduits run to the same point, the great central castellum aquæ, part of which is a cave in a rock, with a larger semicircular basin built out in front of it, over which passes the cross-road from the Via Collatia to Salone.
The line of the specus can be distinctly traced from this reservoir near its source to the city by the respirators over the wells. The smaller castella, or cisterns, at the sources are also still in use.
About four miles from Rome, on the road now called Via Collatia, or Collatina, a portion of the Aqueduct was rebuilt under Benedict XIV. in 1753, as stated on an inscription upon it. It is here carried across a shallow valley, on an agger built of rough concrete faced with brick, for about a quarter of a mile. At the further end is a conduit-head, or a modern castellum aquæ. This is a small oblong building with a semicircular head erected under Pius VI. in 1788, by Joseph Vai; and the conduit was continued by him for the length of 175 feet, also stated in an inscription upon it[97].
From this point there is a branch to the south for a short distance, with two respirators visible in the field; but this, though appearing like an additional source, is only a branch leading to an old fountain of a villa.
The main line comes from the north along the bank of the Via Collatia, as shewn by the respirators, at regular intervals of about a hundred yards. These are mostly round masses of concrete with round heads; but some are dwarf pyramids, one of which, numbered “40,” has been rebuilt in 1866. The surplus water is carried into a brook which runs by it, and receives its chief supply from it.
The specus or conduit of the Aqua Virgo passes along the line of the old road in a direct line west, towards the Porta Maggiore, until within about half a mile from that gate; then it makes a great detour to the north, passing under the modern Via Tiburtina, and eventually enters Rome through the Pincian Hill a little to the north of the Spanish steps, and there is a reservoir for it at the end of a short street called the Via del Bottino. It then goes to the present fountain of Trevi, passing at the back of the houses in the Via del Nazareno, where it may be seen in several of the courtyards. In one of these, on the left hand of the street, is an inscription recording its repair by Claudius[98]; in another, on the right, is an ancient lavatory below the level of the street. A branch passes under the Via dei Condotti carried in leaden pipes, enclosed in a brick specus; this branch is the one that led to the Thermæ of Alexander Severus, which were situated to the north of the Pantheon. The main line supplied those of Agrippa, for which this aqueduct was made. The Aqua Virgo chiefly supplies the fountains and houses in the Campus Martius, or lower city, and the main stream terminated originally in front of the Septa[99], considerably to the south-west of that fountain. In some excavations made in the summer of 1871, a portion of it was found in the Piazza di S. Ignazio. This original termination was at the north end of the Septa, very near the Pantheon.
This aqueduct was restored by Pope Hadrian I., A.D. 772-795, after it had been damaged by the Goths. It was afterwards repaired by several subsequent pontiffs, especially by Boniface IX., A.D. 1389, and by Nicholas V. in the fifteenth century. It now supplies the fountains in the Piazza Colonna, erected in 1574; at the Pantheon, restored in 1711; several others of the seventeenth century; and that of the Trevi, erected by Benedict XIV. in 1730.
Near the source of the Virgo passes an abundant stream, also called Marrana; but this has mineral properties, and was therefore carefully avoided in forming the aqueduct for the Virgo. Pliny says[100] that there was a stream which was abhorred by the Virgo, and for that reason the water was called the Virgin. This stream was called by him Rivus Herculaneus, some say for its salubrious qualities, because Hercules was the god of health; others because it was a strong stream. There is little doubt that this is the stream here described. The same name of Herculanean is given by Frontinus to the stream now called Marrana[101] in two places, because it was also a strong stream.