In treating of the Aqueducts we have a trustworthy guide in a writer who flourished in the time of the Emperors Nerva and Trajan, namely, Sextus Julius Frontinus[2]. While he informs us of what improvements he made during the time he had the charge of these important public works, he also gives in his treatise a historical account of the several changes which had been from time to time made in the means of supply of water to the Imperial City, which kept pace with the growing wealth and population of Rome. When he died they had probably reached perfection, and were justly the admiration and surprise of all travellers[3].

His treatise is well worth examination, not only from an archæological point of view, but as suggesting also many curious enquiries as to the engineering abilities which the Romans possessed, compared with those exhibited at the present day. In elucidating, however, the architectural antiquities of the city of Rome, it will be necessary, as far as possible, to limit the extracts from his treatise De Aquæductibus, to those portions which refer either directly to existing remains, or which indirectly explain them, by pointing out the principle on which the several Roman aqueducts seem to have succeeded each other.

Frontinus tells us in his fourth chapter, that for 441 years after the building of the city, or until B.C. 312, the people were content with the water which they could draw from the Tiber, or from wells[4] or from springs, of some of which the memory was in his time still held sacred and honoured, for they were thought to afford health to the sick[5].

Passing to his own time, he says, “there now flow into the city:”—

Frontinus describes the above nine aqueducts in order, giving details as to the source of the water in each, the quantity, and the distribution. Such extracts as are calculated to throw light upon the existing remains, are given in the course of the following remarks. Seven other Aqueducts were added after the time of Frontinus at different periods, of which an account will also be found in the second part of this Chapter.

I. The Aqua Appia (A.U.C. 441, B.C. 312).

“The Aqua Appia was brought into Rome by the censor Appius Claudius Crassus, afterwards called Cæcus (the blind), who also caused the Via Appia to be constructed from the Porta Capena to the city of Capua[7].”

“The Appian stream rises in the Lucullan fields on the Via Prænestina, between the seventh and eighth milestone, and about 780 paces (or about ¾ of a mile) off on the left-hand side. The channel from its source to the ‘Salinæ,’ which is a spot near the Porta Trigemina, measures 11 miles, 190 paces (about 300 yards) in length. For 11 miles, 130 paces, (about 200 yards,) the channel runs underground, and for 60 paces (about 100 yards) it is carried above ground on a substructure and arcade (in the part) nearest to the Porta Capena[8]. At the ‘Spes (Specus) Vetus,’ (the old specus or conduit,) on the confines of the Torquatian and Pallantian gardens, a branch called the Augustan was added to it by Augustus as supplementary, whence it received the name of ‘Gemelli[9]’....”

“The distribution of the Appian water begins at the bottom of the Clivus Publicii at the Porta Trigemina[10]; the stream having passed beneath the Cœlian and Aventine Hills.”

“... The measure at the head of this could not be obtained because it consists of two channels. At the Gemelli, however, which is under[11] the Spem (Specum) Veterem, (the old conduit,) where it joined with the Augustan branch, I found the height or depth of the water to be 5 ft., the width 1 ft. 9 in., which makes the area 8 ft. 9 in.: ... it should be noticed that the water in many parts of the City was observed to be lost, that is, by trickling away. Moreover we found some of it intercepted by illegal pipes within the City; without the City, owing to the pressure, that which was underground (at the head 50 ft.), received no injury[12].”

The Lucullan fields, in which are the sources of the Aqua Appia, are nearly due east from Rome, on the bank of the river Anio, at about six miles from the present gates of Rome, and three quarters of a mile off the Via Collatina, now a cart-road. This is the old Via Prænestina, which went through Collatia, now called Lunghezza, about two miles higher up the river Anio, at the point where the smaller river Osa falls into it. In this part the old paved road remains for some distance in use, both before and after the entrance to Collatia, and was the more direct road; the present carriage-road, now called Prænestina, was the Via Gabina, and went through or near to Gabii, but was not so direct a line to Præneste or Palestrina as the one through Collatia. The old road passes close in front of the ancient stone quarries, on the bank of the Anio, in which one of the springs or reservoirs of the Aqua Appia is situated; the pavement of it remains, and is now used as a foot-path only.

There are several springs or sources for this aqueduct, and also several ponds to collect the rain-water, made in the clay, the water from all of which was collected into a central reservoir cut in the rock, with a large well over it. There are also seventeen wells visible in two lines, eight in one and nine in the other, converging and meeting in the central reservoir. The soil is clay upon stone. The specus is here a large tunnel cut in the rock, and the wells descend into it. They may be distinguished from above by the bramble-bushes which grow over and cover each of the openings, and do not grow on the other part of the field; each well is also protected by a wooden rail, to hinder cattle from falling into it. The water still runs through in some parts. Near to this reservoir is a tomb of very early character, similar to what are usually called Etruscan[13] tombs, cut out of the rock.

As the length of its course was rather more than eleven miles, while the distance by the Via Prænestina direct was only between seven and eight, it is clear that it did not follow that road. It was carried to the south towards the Via Labicana by a winding course, according to the levels of the ground. The Aqua Virgo, whose source is in the same Lucullan fields as the Appia, is carried to the north by another winding course of a greater length, to supply the northern parts of the city.

The course of the old Via Prænestina[14] has undergone but little change, and the 7th milestone is soon measured. A little beyond it, and 780 paces off on the left of the road (i.e. on the northern side), we are brought to a point[15] where the sources of the Aqua Appia are still to be seen in caves formed by ancient stone quarries, near a tenement called La Rustica. One cave is of a triple form, with three springs, and the soil above the stone is much mixed with clay. These three springs meet at the mouth of the cave in one stream, which runs in the old specus cut in the rock, but open at the top, and having the appearance of a mere country ditch, half hid by the grass and weeds in the winter, and in the summer months entirely concealed by them. This specus runs across a low meadow for about a quarter of a mile. It crosses the line of the Aqua Virgo, the respirators of which cross this meadow in an opposite direction; the sources of the Virgo are about a mile further from Rome, on the same road. It then enters the rock again in a tunnel, and at this point is the first castellum or reservoir, with a large circular well cut out of the rock, which forms the vault over it. There are the grooves for sluices at each end of the reservoir, and an opening has been made into the tunnel a little beyond this reservoir. The course of the aqueduct is then in a tunnel entirely underground, in the direction of a series of ancient caves, through which, or by which, it must pass, but being underground it cannot be seen. These caves are evidently an ancient stone quarry, but of later character than the one first mentioned. In the earliest one, at the source, the stone has been split off the rock, not cut; in the other caves, the stone has been well cut, and of these many are to be seen, the openings being large square apertures like doorways, but side by side in the face of the scarped cliff, not following each other: a practice common in quarrying, where the circumstances require it, down to the present day. Between the chambers are massive square or oblong piers, left to support the vault and the earth above. At the bottom of one of these chambers is water running from another spring, and the shepherds state that there is an opening from it to the specus of the aqueduct; but as the bottom is filled up to the depth of several feet with broken stone, it cannot be seen. Some of the chambers of this ancient quarry have been used as a burying-place, probably for the neighbouring town of Collatia. The graves are cut out in the side of the walls, like the loculi, and there are also chambers like the cubicula of a catacomb. The tombs of this necropolis of Collatia are very ancient, perhaps anterior to the Kings of Rome, and certainly not posterior to the Republic. This stone has been cut out in large square or oblong blocks, such as are usual in work of the time of the Kings; it is probable that Appius Claudius made use of a quarry which he found, and that the ground was not excavated for the purpose of the aqueduct only.

From this point the course was entirely underground, therefore no traces are visible without some difficulty. Incidentally, as we have seen, Frontinus notes, that at the head the water ran as much as fifty feet below the surface, and was thus protected from being fraudulently diverted. It could not have taken a very direct line, as the levels of the crossing valleys must have necessitated here and there a circuitous course; and moreover this is clearly implied by Frontinus, who says that the total length from the source to the “Salinæ” was more than eleven miles, while the distance in a direct line is less than nine miles. As it had no piscina[16], it flowed on in an uninterrupted course to the spot where it was distributed for the public service.

One branch seems to have entered Rome under the line of the Claudian arcade, near the Porta Maggiore[17], and its course within the city is not difficult to follow, since for certain purposes access has been made in more than one place into the old specus, part of which is used to carry the lead pipes of the Aqua Felice to the Hospital of the Lateran and other places. From the surface where one of the shafts is situated to the bottom of the channel, is a depth of twenty-five feet. No water runs along it at present, except in the metal pipes from the Aqua Felice, belonging to the modern system.

The direction of this channel, after it enters Rome, happens to be easily seen above, as it is marked throughout its course, from the eastern end of the Cœlian to the Arch of Dolabella, by the fine arches of the Neronian branch from the Claudian Aqueduct erected almost over it. It is very probable that one of the laws (referred to by Frontinus as having been in existence long before his time) respecting aqueducts was in force from the commencement, namely, that there should be no buildings of any kind within ten feet on either side of the aqueducts; thus an open space was probably existing at the time when Nero wished to carry water to his magnificent reservoir at the north-western end of the Cœlian, and of this he availed himself in rearing the splendid arcade which is called by his name. It will be remarked, however, that the brick buttresses actually came down to the flat roof of the original specus of the Appian. The top of that specus was raised to a greater height by the engineers of Sixtus V., and in this enlargement the underground supports of the Neronian arches are cut through to give headway to the aquarii passing along the channel. They have however to stoop their heads as they pass under each buttress.

The old tunnel specus was discovered in the time of Sixtus V., (Felice Peretti), filled up by clay deposit to the depth of three feet, or half the height of the specus, as in other places, and the builders found it easier to raise it, for the aquarii to go along it, than to clear it out. They therefore knocked away the flat tile-covering of the time of Nero, and raised a vault of rubble-stone three feet higher.

From the great subterranean reservoir, still in use for the water of a spring, near the Arch of Dolabella, to the edge of the western cliff of the Cœlian is but a short distance, and here the specus seems to run in a bank dividing the vineyard or garden of the Villa Mattei from that of the monks of S. Gregory, on which a wall has been built. At this point subsequent alterations, and especially those under the Emperors Nerva and Trajan, have buried to a great depth the actual remains of the original aqueduct; but this later work occupies the same line, and must be described. We first come to a large piscina or filtering-place on the cliff of the Cœlian, immediately above the Porta Capena. This piscina is divided into two parts, one above the other; but both are below the top of the cliff, and are faced with brick and reticulated work of the time of Trajan. There are remains of two specus running along against the face of the cliff; of the upper one the lower part, or pavement, of Opus Signinum, only remains, and this runs down in a sloping direction from the upper reservoir to a lower one, a little to the south of it, which is very extensive. This lower reservoir consists of several parallel chambers, through which, or rather in front of which, another specus runs at a lower level; this appears to be horizontal. This specus goes on in the direction of the ruins of a building of various periods, possibly the remains of the Ædes Camenarum, and passes then to the south in the direction of the Thermæ of Severus and Commodus.

Another branch was evidently afterwards made from the upper reservoir going towards the north for a very short distance, merely for one of the usual angles; then, turning again to the west, in the valley below, there is another large castellum aquæ, or reservoir of five chambers, all as usual oblong and side by side. This is on lower ground, and is built upon the wall of Servius Tullius, where it crosses the valley; the upper part of this reservoir has been made into a house for the gardener. The underground part of the chamber nearest to the Cœlian is built of the large square blocks of tufa usual in the time of the Kings, and belongs to the fortifications of the Porta Capena, over the Via Appia, which here passed close under the Cœlian; the other chambers appear, from the bricks, to be of the time of Trajan. From this point to the Piscina Publica, the line of tall brick piers of Trajan can be distinctly traced by the existing remains, passing across to the other side of the road and of the stream here close to it[18]. The ruins of the Piscina Publica, as rebuilt by Trajan, remain visible under the corner of the Pseudo-Aventine, near S. Balbina, and from this the water was again distributed in different branches. At this point, let it be observed, and only at this point, is the valley which divides the Cœlian from the Aventine sufficiently narrow to admit of agreement with the direct and clear assertion of Frontinus, that here alone, throughout the whole course, was it carried on a substructure and on arches for a distance of one hundred yards.

Although there are no remains of the specus now visible at this spot, because the gate has been destroyed, there can be little doubt that the channel for the water was carried over the southern gate of the city according to its extent at that time. This gate was called the Porta Capena; and as the Appian aqueduct was allowed to fall into decay, it gave rise to the descriptions both of Martial and Juvenal, who describe it as wet or moist[19].

The excavations made in 1868 and 1869 under the direction of Mr. Parker, with the help of the British Archæological Society of Rome and the Roman Exploration Fund, have clearly shewn the specus of the Aqua Appia and those of two other aqueducts carried upon the agger of Servius Tullius across the valley from the Cœlian to the Aventine, with branches to the left running into the subterranean chambers of the Piscina Publica. These underground chambers are of the time of the Republic, the walls are built of rubble stone as usual at that period, and there are small openings through these walls for the circulation of the water, although the upper part has been rebuilt in the time of Trajan, as the remains of the wall are faced with the brickwork usual in his time. The lowest specus is cut out of tufa rock under the wall of Servius Tullius, which is built of the usual large blocks of tufa.

The principal branch went underground to the cave reservoir at its mouth, on the level of the quay of the Marmorata between that and the Salaria, just outside of the old Porta Trigemina; the old agger in which that gate was situated still forms the southern or lower boundary of the wharf of the Salaria. Part of the course of this earliest specus, that of the Appia, can be traced and seen in a subterranean stone quarry nearly under S. Sabba. The specus is six feet high and two feet wide, and it is filled up to nearly half its height by solid clay, evidently the deposit left by the water. The old specus, long after it had been out of use, seems to have been employed by the quarrymen: as it was a tunnel in the tufa rock just high and wide enough for a man to walk in, by cutting away one side they made it wide enough for a horse and cart to carry the stone, and they raised the vault as high as was convenient for the purpose of making an entrance into the quarry. The series of wells descending into the old specus from the gardens above remain at intervals, with notches for steps cut in the rock to enable a man to go up and down when required. The course of the specus is cut off by the road to the Porta Ostiensis, but probably that road was originally carried over it[20] at the crossing; it then passed through another large subterranean quarry nearly under S. Prisca, to the cave reservoir at its mouth[21].

Before arriving at the two large reservoirs just outside of the garden of the Sessorium, now Sante Croce, the specus of the Appia must have passed by another smaller reservoir at the same low level, near the ruins of the apse of a hall, miscalled the temple of Venus and Cupid. This seems likely to have been the point at which the branch specus, coming from the north, entered Rome, and it was then carried on to the two large reservoirs outside this garden, supposed to have been the Gemelli[22].

Below the “Salinæ” or salt warehouses on the bank of the Tiber, and near the “Porta Trigemina,” the water was “distributed.” This was also close under the Clivus Publicii, or the slanting zig-zag road leading up from the wharf to the top of the hill.

So far the general course can be traced; but the exact point of entrance into Rome could not be fixed without excavations, which have not as yet been made. There are, however, some data given by Frontinus which should not be overlooked, as they bear incidentally upon the course of some other of the aqueducts.

First, it should be remarked, that the water of the Appia was augmented by an additional stream. This was not accomplished till the time of Augustus. The source of this latter[23] was on the same side of the Via Prænestina, but a little nearer to Rome (near the sixth milestone) we are told, and its course was, like the main stream, entirely underground. It was more direct, as its length was less than six miles and a-half, while the original stream, by its windings, required about eleven miles to complete the same distance[24].

It joined, however, the Appia at the “Spes (Specus) Vetus,” and at the Gemelli[25], which was under (infra) the “Old Specus,” it could be measured. This is an important landmark; it is well at once to observe that the usual interpretation of the passage as referring to a “Temple of Spes,” and the statement that a temple occupied the site of some ruins which are marked thus in a few maps, (in most, Templum Veneris et Cupidinis) does not seem to fit the circumstances. It is proposed to read in both these two instances “Specus Vetus.” The expression occurs, altogether, five times in Frontinus, and it will be most satisfactory therefore to consider the passages together, which will be done more conveniently in connection with the next aqueduct described.

The Torquatian and Plautian, or Pallantian gardens, seem by the context to have occupied a spot on either side of the point of junction of the two streams. The Torquatian gardens are not mentioned elsewhere, and with respect to the Plautian[26] (which is only conjectural, and has the authority of neither of the early MSS.), it has been suggested to read Pallantian, which gardens are mentioned twice elsewhere by Frontinus in connection with the Specus Vetus, besides once in such a way as to imply the same[27].

The Torquatian gardens probably occupied the space between the outer wall and the modern “Via di Porta Maggiore,” and were probably those of Titus Manlius Torquatus, a member of an important patrician family; Livy mentions at least three generations of that name. This ground shews numerous remains of aqueducts and reservoirs, and here also is the fine building of the third century called the Minerva Medica, which was probably the nymphæum of some thermæ of that period[28]. The Pallantian gardens is a natural name for those belonging to the Sessorium, or the Sessorian fortified Camp and Palace[29], and occupied the low ground near it. They would therefore be to the south of, but adjoining to, the Torquatian gardens.

II. The Anio Vetus (B.C. 272).

Passing on to the second aqueduct, namely, the stream taken from the River Anio (and which was called the Anio Vetus to distinguish it from a later diversion from the same river), we find that Frontinus is also very distinct in many of his details; a few only he leaves to conjecture.

The point where a branch was taken from the river Anio can be traced[33]. There was a reservoir by the side of the river, of which some ruins remain; but it was nearly destroyed a few years since by some peasants in their ignorant and too eager search after hidden treasure which they expected to find there. The specus is cut in the rock as a tunnel in the cliff of the valley of the Anio, just below the level of the road; it follows the line of the cliff, of the river, and of the road: for they are all the same, the only opening through the rocky mountains of limestone in this part, obviously made by the river itself. It follows this line as far as the valley called the “Valle degli Arci,” or of the Arches, where three later aqueducts cross the river on arcades about two miles above Tivoli. At this point several aqueducts are visible crossing the valley on arcades, each on a separate arcade, not three on one arcade and two on another, as near Rome. The one nearest to Tivoli is the Marcian, and at the foot of one of the piers of the arch, which here crosses the road, the specus of the Anio Vetus is visible, partly underground, but the upper part above ground, on the right-hand side of the road in going from Tivoli. It then is carried in a tunnel through the hill, but appears again on the other side with a large reservoir, and runs gradually downwards in a winding course round part of the hill.

It is not easy to distinguish to which of the aqueducts belongs any one of the numerous reservoirs, the ruins of which are conspicuous objects on the roads up to Tivoli on the other side towards Rome, especially along both sides of that called the “Promenade of Carciano,” for the distance of about three miles from Tivoli. The specus and reservoir of the Anio Novus are on a natural terrace above that road, and the Marcia below it; these have passed through Tivoli, winding round that end of the hill. The Claudia passed upon a great arcade the valley of the Arci, and another valley in the direction of Gerocomio. The Anio Vetus was carried in a tunnel through the hill, and appears on the other side near Tivoli, at a considerably lower level than the others. The road passes across the specus, and is made upon the surface of the vault, which is visible about four miles and a-half from Tivoli. A little further on there are two large reservoirs belonging to it, near a modern villa called Gerocomio, built by the Cardinal Santacroce in the year 1579, now a farm-house only, but on the site of an ancient villa, of which some remains are built into the walls. One of these reservoirs or piscinæ (?) appears to be unaltered, the buttresses remain and apparently the vault; but it is covered with herbage and shrubs, which conceal it. The other has been turned into a cottage or an out-house of the villa, and this is of later date than the other. The Anio Vetus, the Marcian, the Claudian, and the Anio Novus, all have to be conveyed down this lofty hill from the high ground on which the remains above mentioned are situated, to the valley below. The river Anio itself rushes straight down the celebrated cascades by a fall of about a hundred feet; but the channels of the aqueducts follow a winding course, which allowed of the descent towards Rome being very gradual.

This road or promenade of Carciano is rather high on the side of the hill above the villa of Hadrian, looking towards Rome. The dome of S. Peter’s is distinctly visible from it. The road is on a ledge on the side of the cliff, and the aqueducts run along the steep side of the hill or cliff, until they come to the valley of a small stream winding down to the Anio; along the cliff of this they are then carried. The Anio Vetus being at a considerably lower level, is more difficult to trace than the others; but it seems clear that after the later aqueducts had arrived at the point where the Anio Vetus emerges from the hill, they all followed the same line, winding along with the small stream, and their specus or channels cut in the cliffs as far as they could be made available. The Anio Vetus has been discovered at the left hand of the modern road to Rome, and to the right of the promenade of Carciano. It passed, upon a lofty bridge called the Ponte di S. Antonio, over a torrent, with the Marcia. Afterwards upon another bridge called Ponte delle Mole di S. Giovanni, and over the Ponte Lupo it went with the others. Near Gallicano (or the ancient Pedum) are two cippi of Augustus in two wells of his specus; one is in the country called Le Sette, and another at Obrego[34] dell’ Ermito. The others have all been followed, and an account of them will be found under their respective heads.

In order to avoid the many small valleys occupied by streams which run parallel to each other from the hilly ground on the south, down to the river Anio on the north, (the general course of which river is west and east,) the course was kept along the higher ground, and in fact wound round the heads of those valleys in order to retain a level, gradually becoming more and more depressed, till, by the time it reached Rome, the base of the specus (according to the computation of Piranesi), was 55 ft. above that of the Appian[35]. The whole course is underground, as has been said, except for 221 paces (about 360 yards); for this short distance it was carried on a substructure above ground. It is reasonable to suppose that this exception to the subterranean course was, as in the case of the Appian, within the present boundary of the city.

Before it reached Rome, two circumstances have especially to be noted. Just within the fourth milestone we are told it had a reservoir and piscina or filtering-place, and at the second milestone it parted[36] with some of its water, which was conveyed to Rome in a separate channel.

This fourth milestone was clearly on the Via Latina, as Frontinus in the previous paragraph had referred to some piscinæ at the seventh milestone on the same road; and it appears, although the sentence is exceedingly corrupt, that the course of the Aqueduct left the Via Latina at this point, and crossed towards the Via Labicana “amongst the arches[37]” at the fourth milestone. The specus is here visible, and appears to be perfect; it is very near to the Torre Fiscale[38], between that and the Osteria, called the Tavolato (which itself appears to be made out of another, but a later, reservoir belonging to the aqueducts, as many of the houses in the Campagna have been). The vault of the old castellum aquæ or piscina is now covered with turf, but the side of it forms a sort of cliff like the edge of a quarry.

This place, where the Anio Vetus leaves the Via Latina, is near the great junction and crossing of the aqueducts, over which the tall medieval tower called the Torre Fiscale has been built. Here six aqueducts meet and cross each other. The Marcian arcade, with three of these, makes one of its many angles, and the lofty Claudian arcade, with two more, is carried over it. The expression that it passed amongst the arches is a very natural one, to any person who knows the locality, as there are many arches at this point. It then goes on to another angle and crossing of the great aqueducts, where there is a gate called Porta Furba, about two miles and a-half from the Porta Maggiore. There is a castellum aquæ of the time of Nero, with an ancient piscina under it, and a fountain of Sixtus V. by the side of it. At the second milestone it parted with some of its water into the specus called the Octavian, which enters Rome at the Asinian gardens, following the direction of the new road.

By referring to the maps it will be seen that the original line of the Via Latina united with the Via Appia within the outer wall and before reaching the old southern entrance of the city (the Porta Capena); but, in joining this latter road (the most convenient course to pursue in the then state of the fortifications), the Via Latina swerved rapidly to the south-west. Had it been continued in a direct line, it would have reached the Cœlian Hill, near the Porta Asinaria, as the Via Appia Nova still does, following the line of the old Via Asinaria.

At this second milestone also is another castellum aquæ[39], mentioned by Frontinus as two miles from Rome. This is near the Porta Furba; it is entirely buried, but the vault of it is not many feet underground. In the spring of 1871, some excavations were made under my direction in a large vineyard hard by, and another subterranean reservoir was found near the road to Tusculum and Frascati, with a specus cut in the rock going in the direction of that road, and apparently passing under it, on the line of a cross-way to the Via Appia Nova, a short distance only. On the other side of that is the “Albergo dei Spiriti,” near the junction with the Via Latina; and, in the garden at the back of that house, a specus was found in a stone quarry, the vault of which had fallen in and brought the specus to view. It seems to have passed underground along the southern side of that ancient Via for a short distance, and then crossed it to a piscina, of which there are remains at the foot of the bank on which the road runs in that part. It then goes along the edge of some higher ground, and for a short distance underground again towards a by-lane (diverticulum), parallel to the Via Latina; remains of a brick arcade can be seen on the bank of that lane, which is a deep foss-way, and goes on to Rome about a mile distant. It is cut by the railway before it arrives at the wall of Rome. It then passes through that wall and underground again as far as the arch of Drusus, over which it passes; and thence on an arcade, part of which only remains, to the great piscinæ at the back of the thermæ of Caracalla[40].

The Via Appia Nova was probably made in the time of Frontinus, and is the road which he calls Via Nova. The part nearest to Rome was previously called the Via Asinaria, and extended from the Porta Asinaria to the junction with the Via Latina, at three miles from Rome, which name was then dropped. The new road continues parallel to the Via Appia Antiqua as far as the eleventh milestone, and there forms a junction with it. Both of these roads are now open. The railway to Capua and Naples passes near to this point of junction. The short Via Lateranensis, going out of the Porta Lateranensis (excavated in 1868), ran into the Via Asinaria, and so joined the Via Appia Nova, which has tombs of the first century along the line, and none of any other period. Those which were of stone have been used as a quarry by the farmers to build the low walls that line the road on both sides, the foundations only being left in the banks; but those which were built of concrete faced with brick, would not pay for the trouble of destroying them, and have therefore been left standing in their places. One of these, a very fine one, faced with brick of the time of Trajan, with moulded pilasters, remains nearly perfect near the seventh mile, just where a path turns off to the left across the fields to the piscinæ, which are near the line of the old Via Latina in this part, about half-a-mile from the Via Appia Nova, and forming the carriage-road to Albano through Marino. It left Rome by the Porta Asinaria as it now does by the modern Porta S. Giovanni, which is close to the old gate, but at a much higher level. The Via Latina crosses it in a diagonal line, and runs nearly parallel to it as far as the Torre Fiscale, that is, for about a mile gradually diverging from it.

Wherever the exterior of the specus of the Anio Vetus is visible, it is faced with Opus Reticulatum. The reservoirs of this Aqueduct are of the same construction, and this may serve to distinguish those on the slope of the hill at Tivoli from the other aqueducts there.

“The water of this straight branch,” says Frontinus, “coming within the Porta Esquilina along the Spes [specus] Vetus, was carried down into the city in the high streams[41].”

This specus is on the high bank of the Tarquins, the outer and lofty line of defence on the eastern side of Rome. On this the wall of Aurelian was afterwards built. After its entry into Rome, the Anio Vetus was divided into several branches, in the same manner as the later aqueducts were.

The right-hand branch, in crossing the Campagna, appears to have run nearly under the Marcian arcade, which was afterwards built on the same line and nearly over it. As we approach near to Rome, there are remains of a reservoir built of large stones a little way down the road, about a hundred yards from the Porta Maggiore. It enters Rome under the wall, almost on the level of the ground; the upper part of the specus was visible in 1868, but in 1869 was studiously concealed by a modern brick wall. It is visible again inside the wall, on the other side of the road, going into the vineyard in which the Minerva Medica stands, while one branch went to the great reservoir near to it, westward of the gate.

Another branch passes along the bank under the wall of Aurelian, and is not visible again until it reaches the Prætorian Camp, where a portion of it was excavated in May, 1868, built of large stones of tufa, under the Porta Chiusa. It may then be traced all round the three sides of the Prætorian Camp, and near the north-east corner there was, in 1868, an opening into it, now closed by a modern wall. It is distinctly visible in several places, especially on the north side of the Camp, where the wall of Tiberius remains perfect, faced with the fine brickwork of his period, whereas the specus under it is faced with Opus Reticulatum, probably of the time of the Republic. The wall of Tiberius distinctly stands on the old specus. There was an opening into it here also in 1868; but this was also carefully walled up in 1869 under the influence of the Garibaldian panic, which had a bad effect upon the Roman authorities at that period. Remains of a reservoir or castellum aquæ were also found on the surface of the ground on the bank near the Porta Chiusa, with the present wall of Rome built right across it, but this part of the wall has been rebuilt of old materials, and is not exactly in the same line. There are remains of several other reservoirs on the bank at intervals outside the wall in the modern road, and in many places all along the eastern and southern sides of Rome.

Beyond this, near the Porta Nomentana, are the ruins of another reservoir or piscina on the surface of the ground, against the wall. From near the Porta Chiusa another branch went along the old road, which passed through that gate across the inner foss to the Thermæ of Diocletian, where a part of the specus and two cippi, with two inscriptions upon them, naming this aqueduct the Anio Vetus, were found in the year 1861, when the railway was made[42]. These cippi are now in the Vatican Museum.

Another branch went from the reservoir near the Porta Maggiore before mentioned, across the road into the bank on which the arches of Nero stand, near the Lateran, and passed under them apparently into the old specus of the Appia, which runs parallel to and nearly under the arches on the other side. Two small specus or stone pipes can be still seen (in 1872) passing obliquely into that bank; and, as they came from this large reservoir and piscina, (or from this direction,) they seem to have belonged to two aqueducts at different levels. A branch of the Marcian may have been brought to the same filtering-place for distribution, and the surplus water carried into the old specus at the lowest level, which was evidently used for receiving and carrying off the surplus water of all the other aqueducts in the same line.

The fifty yards outside the wall added to the three hundred yards between the Cœlian and the Aventine, make up the three-hundred-and-fifty yards above ground, mentioned by Frontinus. In this valley we found it again, in 1869, parallel to the Appia, sometimes on the agger or bank of Servius Tullius, which was used as a substructure for it, in other places on an arcade built up against the tufa wall of Servius Tullius, and faced with reticulated-work.

APPENDIX.
On Spē or Spc̄.

For the supposed Temple of Spes, the ruins of an apse in the gardens of S. Croce, of “Venus and Cupid,” (as it is marked in most maps, and as “Speranza Vecchia” in others,) was fixed upon by Piranesi, who carefully examined all that he could with a view of mapping out his aqueducts, according to the knowledge possessed in his time. This building was no doubt a hall belonging to the Sessorian Palace. Others, again, have suggested the so-called temple of Minerva Medica, but this again is a nymphæum, or pantheum, and not a temple at all. Besides, a further difficulty lies in one being too far south, while the other is too far north.

Canina, in his account of the results of the excavations at the Porta Maggiore[43], and of the tomb of Eurysaces the baker there discovered, just outside of the gate, gives a plan in which he inserts a temple just inside the gate on the southern side, which he calls the Temple of Spes[44]. It is quite possible that this was a Temple of Spes. There certainly was a temple on the site indicated, where the modern guard-house stands; and during excavations carried on there, fragments of a temple of the time of the early Empire were found, consisting chiefly of a fine cornice of travertine.

When, however, the words of Frontinus have to be applied, the difficulties of the theory of his referring to a temple are increased. In the case of the expression last referred to, “following the specus (spes), or, according to one manuscript, the old specus, which is obviously the sense,” it is very difficult to imagine what circumstances there were in connection with a temple which could warrant the use of such words; and even in the instance mentioned, where we were noticing the Appian aqueduct, “the expression, the Gemelli, which is a place under the old specus (Spe̅s̅ Vetus),” is somewhat singular. Granting that a temple once existed just within the wall of the city (which, from the context, must have been its position if any) it is singular that he should use it as a landmark when describing the junction of two streams of water. The remaining three expressions are simply “at the old specus (Spe̅s̅ Vetus[45]).”

With these difficulties to contend with, it has been thought well to seek a different solution, and this is found in the reading of “Specum Veterem” for “Spe̅m̅ Veterem,” i.e., the “old specus.” With this reading, it naturally follows that it would refer to the old specus, or the specus of the Appia and the Anio Vetus; and it is singular that the first time it occurs in Frontinus, the Codex Urbinas[46], only second in authority to the Codex Cassinensis, has the reading “Anienem Veterem,” instead of “Spem Veterem.” What was the true reading of the Codex or Codices from which these two copies were made, it is impossible to say; they are the earliest we have, and it is clear from several other instances that the scribes did not copy with much knowledge of the matter in question: then it was easy to mistake Spc̄ for Spē. That it was the Specus Vetus which was meant, must rest therefore upon the circumstances which allow of its application to the passages named, and it remains to shew that this is the case.

In the instance under discussion, the water of the Anio is said to flow along its own specus, and therefore it would not be probably possible to find an interpretation more suitable as far as this case is concerned. The conduit of the water of the Anio Vetus had “emerged,” as the other aqueducts emerge, near the Porta S. Lorenzo, from the higher ground between the Porta Maggiore and that gate: it must consequently have been carried on a substructure from that point on the outer bank of the original fortifications of Rome, that is, on the high bank on which the aqueducts were carried, and on which the wall of Aurelian was afterwards built, to the inner bank, on lower ground faced with the tufa wall of Servius Tullius. The names of the gates are matters of dispute, and are quite immaterial; the levels of the ground decide the question[47].

In another place, Frontinus says[48] that several streams of water, and first the Marcia, were carried to the Aventine from the specus (a spe-cu), that is from the old specus he had before mentioned on the Cœlian, and obviously from the west end of the Cœlian. The Temple of Spes of Canina and others at the Porta Maggiore, is at least a mile from the Aventine. The only way of giving an intelligible meaning of the passage is that the author refers to the old specus he had before mentioned, as leading along the Cœlian to the Porta Capena. In the excavations made in 1868 and 1869, on the line of the wall of Servius Tullius from the Cœlian to the Aventine, the conduits of three specus were found, two of which must have passed over the arch of the Porta Capena, in order to cross the Via Appia, there a deep foss-way. Two conduits were seen in each of the pits that were dug at intervals along the line, and at the junction with the Piscina Publica under the Aventine they were all three perfect; the lowest one is there cut in the tufa rock under the wall, the other two are on the wall, and partly cut out of it.

Piranesi has preserved a sketch of the specus of the aqueduct, which he supposed to be the Anio Vetus upon its substructure; but he gives no clue as to the exact spot whence that sketch was taken[49]. In its character the masonry is very similar to that of the Marcian, but there are minor differences sufficient to shew that it belongs to an earlier age.

Those who have paid attention to the manner in which ancient books have been transmitted to modern times before the invention of printing, and who are familiar with the use of records and of other medieval manuscripts or transcripts, well know how full of abbreviations they are, and how difficult it often is for the editor to fill up these abbreviations, if he does not happen to know the word intended. The name of specus for the conduit of an aqueduct was essentially a technical word. The first transcribers of the text of Frontinus were not Romans, and did not know the term: hence they filled up the abbreviation spē, or perhaps originally spc̄, with spem or spei, instead of specum or specûs. The same thing may have occurred in the text of Lampridius (as mentioned in a note on a preceding page).

The Abbot of the monastery on Monte Cassino (now a public school and public library) has kindly given me tracings of all the passages in that manuscript in which this abbreviation occurs, and I have had them reproduced by photography and phototype on the page annexed. Opposite to this the same passages are given in the Italic characters, and a few words that are necessary to complete the sense in Roman characters. This is followed by an English translation of these passages, and by some extracts from Livy and other authors in explanation.