Chapter X: The Marbles of Ancient Rome (1)

Marble-hunting is one of the regular pursuits of the visitor in Rome. The ground in almost every part of the ancient city is strewn with fragments of historical monuments. The largest and most valuable pieces have long since been removed by builders and sculptors, to fashion some Papal palace, or to adorn some pretentious church; and at the present day, in almost every stone-mason's shed, blocks of marble belonging to ancient edifices may be seen in process of conversion into articles of modern furniture. Many bits of the rarest kinds, however, still remain, which not unfrequently bear traces of the richest carving. For ages such spots have been quarries to visitors from all parts of the world, who wished to bring home some memorial of their sojourn in the Eternal City, and the supply is still far from being exhausted. That so much material should have survived the wholesale conversion, during the middle ages, of columns and statues into lime, in kilns erected where the temples and palaces were most crowded, and the vast exportation of objects of antiquity to other countries, is a striking proof of the prodigious quantity of marble that must have existed in ancient Rome. Now, however, such relics are more carefully preserved; and as the places where they are found in greatest quantity have been taken under the charge of the Government, and soldiers are constantly on the watch, it is not so easy as it used to be to abstract a fragment that has taken one's fancy.

Marble fragments are so eagerly sought after because they make most suitable and convenient souvenirs. Their own beauty and rarity, apart from all historical associations, are a great attraction. Many of them will form, when cut and polished by the lapidary, pretty tazzas and paper-weights, and even the smallest bits can be put together in a mosaic pattern, so as to make extremely beautiful table-tops. Whole rows of lapidary shops in the English quarter of the city, especially in the Via Babuino and the Via Sistina, are maintained by this curious traffic. In the Forum and Colosseum great quantities of marble and alabaster used to be found; but these localities have been so much ransacked that they now afford very scanty gleanings. The Baths of Caracalla and Titus, the recent excavations on the Esquiline, the ruins of the palaces of the Cæsars on the Palatine, and the open space marked out for new squares and streets between Sta. Maria Maggiore and St. John Lateran, are the best situations within the walls of the city. Outside the supply is almost as large as ever. All over the vast Campagna the foot of the wayfarer strikes against some precious or beautiful relic; and along the Appian and Latin Ways broken pieces of different kinds may be found in such profusion that such spots look like the rubbish-heap around a marble quarry. In the vast grounds over which the imposing ruins of Hadrian's Villa spread, heaps of fragments of marble flooring or casing may be seen in almost every neglected corner, from which it is easy to obtain some lovely bit of giallo antico or pavonazzetto or green porphyry. Beside the ancient quay of Rome, leading to the ruins of the Emporium or Custom-house--at a spot called in modern phrase "La Marmorata," because marble vessels still discharge their cargoes there--immense quantities of marble, alabaster, and porphyry are piled up, that were unshipped untold ages ago for Roman use; and a vineyard a short way off, on the slope of the Aventine, is much frequented by collectors on account of the richness of its finds.

But it is not as a mere amusement, or as a means of collecting pretty souvenirs of travel, that such marble-hunting expeditions are to be recommended. They may have a much higher value. The different kinds of marble collected are peculiarly interesting owing to their association with the different epochs of the history of the city and empire; and as the specimens which the geologist obtains throw light upon the formation of the rocky strata of the earth, so the small marble fragments which the student finds in Rome afford a clue to the various stages of its existence. Indeed, a competent knowledge of the marbles of Rome is indispensable to a clear understanding of the age of its ancient monuments. An immense amount of controversy has raged round some remarkable building or statue, which would have been prevented had the nature and origin of the marble of which it was composed been first investigated. The famous statue of the Apollo Belvedere in the Vatican, for instance, was long regarded as an original production either of Pheidias himself or of his school. But the discovery that the marble of which it is wrought is Lunar or Carrara marble--which was unknown until the time of Julius Cæsar, who first introduced it into Rome--is of itself a proof that it is not a genuine work of Greek art of the best period, but a monument of the decadence, or a copy of an original, wrought in imperial times for the adornment of a summer palace in Italy. In numberless other cases, ancient monuments have been identified by the mineral character and history of their marble materials. The first thing, therefore, which the student during his visit to the city ought to do, is to make himself acquainted with the different varieties of marble that have been found within the walls or in the neighbourhood. For this purpose the Museum in the Collegio della Sapienza or University of Rome will afford invaluable aid. In this institution, conveniently arranged in glass cases, are no less than 607 specimens of various marbles and alabasters used by the ancient Romans in the building or decoration of their houses and public monuments. The collection was made by the late Signor Sanginetti, Professor of Mineralogy in the University, and is quite unique. A great deal of instruction may also be obtained from the mineralogical study of the thousands of marble columns still standing in the older churches and palaces of Rome, most of which have been derived from the ruins of ancient temples and basilicas. Several excellent books may also be consulted with advantage--especially Faustino Corsi's Treatise on the Stones of Antiquity, _Trattato delle Pietre Antiche_, which is the most approved Italian work on the subject, and from which much of the information contained in the following pages has been obtained.

No marble quarries exist in the vicinity of Rome. The Sabine Hills are indeed of limestone formation, and large masses of travertine, a fresh-water limestone of igneous origin, occur here and there, but no mineral approaching marble in texture and appearance is found within a very considerable radius of the city. The nearest source of supply is at Cesi, near the celebrated "Falls of Terni," about forty-five miles from Rome, where "Cotanella," the red marble of the Roman States, is found, of which the great columns supporting the arches of the side aisles of St. Peter's are formed. The hills and rocks of Rome are all volcanic, and only the different varieties of eruptive rock were first employed for building purposes. The oldest monuments of the kingly period, such as the Cloaca Maxima, the Mamertine Prison, the Walls of Servius Tullius, and some of the earliest substructures on the Palatine Hill, were all built of the brown volcanic tufa found on or near their sites. This is the material of which the famous Tarpeian Rock and the lower part of most of the Seven Hills is composed. It is the oldest of the igneous deposits of Rome, and seems to have been formed by a conglomerate of ashes and fragments of pumice ejected from submarine volcanoes whose craters have been completely obliterated. It reposes upon marine tertiary deposits, and over it, near the Church of Sta. Agnese, where it is still quarried for building stone, rests a quaternary deposit, in which numerous remains of primeval elephants have been found. Though the Consular or Republican period was a very stormy one, and the reconstruction of the city, after its partial demolition by the Gauls, seems to have been too hurried to allow much attention to be paid to the materials and designs of architecture, yet there are numerous indications in the existing remains of that period that there was a decided advance in these respects upon the ruder art of a former age. Finer and more ornamental varieties of volcanic stone were introduced from a distance, such as the _peperino_ or grayish-green tufa of the Alban Hills, the _Lapis Albanus_ of the ancients, with its glittering particles of mica interspersed throughout its mass; the hard basaltine lava from a quarry near the tomb of Cæcilia Metella, on the Appian Way, and from the bed of the Lago della Colonna, once the celebrated Lake Regillus, to which the name of _Lapis Tusculanus_ or _Selce_ was given; and the _Lapis Gabinus_ or _Sperone_, a compact volcanic concrete found in the neighbourhood of the ancient Gabii on the road to Tivoli, extensively used in the construction of the earliest monuments, particularly the Tabularium and the huge Arco de Pantani. Brick was also largely employed in the construction of the foundations and inner walls of public buildings, being arranged at a later date into ornamental patterns, to which the names of _opus incertum_ and _opus reticulatum_ were given; and in the manufacture of this substance, which they were probably at first taught by the Etruscan artificers of Veii in the neighbourhood, the Romans reached a high degree of perfection. The earliest tombs along the Appian Way were constructed of these different varieties of building materials. The sarcophagi of the Scipios were hollowed out of simple blocks of peperino stone; and the sculptor's art and the material in which he wrought were worthy of the severe simplicity of the heroic age.

But towards the close of the Republican period, Rome began to be distinguished for the magnificence of its public monuments. As its area of conquest spread, so did its luxury increase. New divinities were introduced from foreign countries, and domesticated in the Capitol; and these required more sumptuous fanes than those with which the native deities had been contented. The brown tufa of the Tarpeian Rock sufficed for the rude sanctuary of Vesta, the primitive hearth-stone of ancient Rome; but in the reconstruction of the sumptuous temple of Jupiter Capitolinus, which marked the grandest period of Roman history, the most precious stones of Asia and Africa were employed. Statues were imported wholesale from Greece to adorn temples and theatres, constructed after the models of Greek architecture, with pillars, friezes, and floors of precious Pentelic and Sicilian marble. During the last century of the Republic marble became a common building-stone. The tomb of Cæcilia Metella, and the temples of Ceres, Juno Sospita, and Castor and Pollux, indicate the introduction of this precious and beautiful material. But it was reserved for the period of the Empire to complete the architectural glories of the city. Travertine, usually called _Lapis Tiburtinus_, a straw-coloured volcanic limestone excavated in the plain below Tivoli, which has the useful property of hardening on exposure, was now used as the principal building-stone instead of the former lavas and tufas; and the Colosseum, entirely constructed of travertine, which was treated in the middle ages as a quarry, out of which were built many of the palaces and churches of Rome, attests to this day the beauty and durability of this material. Quarries of crystalline marbles, admirably adapted for the purposes of the sculptor and architect, were opened in the range of the Apennines overlooking the beautiful Bay of Spezia, in the vicinity of Carrara, Massa, and Seravezza, and largely worked in the time of Augustus. This emperor could boast that he had found Rome of brick, and left it of marble. The marbles of each new territory annexed to the Empire were brought at enormous expense into the Imperial City. A quay, to which reference has already been made, was constructed at the broadest part of the Tiber, where the vessels that transported marbles from Africa, and from the most distant parts of Eastern Europe and Western Asia, landed their cargoes. Here numerous blocks of marble were lately found, one of which was identified as that sent to Nero from a quarry in Carinthia; and another, a column of even more colossal dimensions, weighing about thirty-four tons of valuable African marble, was meant to serve as a memorial pillar of the Council of 1870 on the Janiculum, but the intention was never carried out. So abundant was marble during the first two centuries of the Empire, that it was nothing accounted of. Every temple, palace, and public edifice was built of it either in whole or in part. The tombs that lined the Appian Way on either side for fifteen miles had their brick cores covered with marble slabs; and their magnificence must have impressed every visitor who entered the Imperial City through this avenue of architectural glory shrouding the decays of death. It is obvious, then, that by studying the history of the conquests of Rome, the student can ascertain at what period a particular kind of marble was introduced from its native country, and the proximate date of the building in which this marble had been used.

It was a fortunate circumstance for the preservation of the precious marbles of Rome that Christianity laid its cuckoo egg in the nest of the Pagan city. When the capture of Rome by Alaric gave the final blow to heathen worship, by the overthrow of the ruling classes, who alone cherished the proud memories of the ancient faith, the greater number of the temples were still standing without any one to look after the edifices or maintain the religious services. The Christians were therefore free to take possession of the deserted shrines; and they speedily transferred to their own churches the columns and marble decorations that adorned the temples of the gods. Many of the precious stones that once beautified the palaces of emperors and senators were employed to form the altars and the mosaic flooring of the memorial chapels. Almost all the early churches were constructed on or near the sites of the temples, so that the materials of the one might be transported to the other with the least difficulty and expense, just as the settler in the back-woods of America erects his log-house in the immediate vicinity of the trees that are most suitable for his purpose. And the striking contrast between the plain, mean exteriors of the oldest Roman churches--rough, time-stained, and unfinished since their erection--and their gorgeous interiors, with their forests of columns separating the aisles, and the series of richly-sculptured and brilliantly-frescoed chapels, all blazing with gold and marble,--a contrast that reminds us of the surprising difference between the outside of a common clumsy geode lying in the mud, and the sparkling crystals in the drusic cavity at the heart of it,--would lead us to infer that the outer walls were raised in haste to secure the valuable materials on the spot, before they could be otherwise appropriated. Marangoni, a learned Roman archæologist, mentions thirty-five churches in Rome as all raised upon the sites and out of the remains of ancient temples; and no less than six hundred and eighty-eight large columns of marble, granite, porphyry, and other valuable stones, as among the relics of heathen fanes transferred to sacred ground within the city, when the bronze Jupiter was metamorphosed into the Jew Peter,

"And Pan to Moses lent his pagan horn."

Many of these relics can be traced and identified, for it may be generally presumed, for the reason already given, that none are very far removed from their original situation.

I know no more interesting pursuit in Rome than such an investigation; the objects, when their history is ascertained, acquiring a charm from association, over and above their own intrinsic beauty and interest. Most of the materials with which the three hundred and sixty-five churches of modern Rome have been constructed have been derived from the ruins of the ancient city. With the exception of a few comparatively insignificant portions brought from the modern quarries of Carrara, Siena, and Sicily, to complete subordinate details and to give a finish to the work, no marbles, it is said, have been used in ecclesiastical and palatial architecture for the last fifteen hundred years, save those found conveniently on the spot; and hardly a brick has been made or a stone of travertine or tufa hewn out for domestic buildings within the same period. The construction of St. Peter's itself involved more destruction of classical monuments than all the appropriations of previous and subsequent Vandals put together. Much has been lost on account of this extraordinary transmutation and reconsecration, whose loss we can never cease to deplore; but we must not forget at the same time that much has been conserved which would otherwise have wasted away under the slow ravages of time, been consigned to the lime-kiln, or disappeared in obscure and ignoble use. Enough remains to overwhelm us with astonishment, and furnish materials for the study of years.

The white marbles of Greece were the first introduced into Rome. Paros supplied the earliest specimens, and long held a monopoly of the trade. _Marmor Parium_, or Marmo Greco duro, as it is called by the modern Italians, is the very flower and consummation of the rocks. This material seems to have been created specially for the use of the sculptor--as that in which he can express most clearly and beautifully his ideal conceptions; and the surpassing excellence of ancient Greek sculpture was largely due to the suitability for high art of the marble of the country, which was so stainlessly pure, delicate, and uniform--as Ruskin remarks, so soft as to allow the sculptor to work it without force, and trace on it his finest lines, and yet so hard as never to betray the touch or moulder away beneath the chisel. Parian marble is by far the most beautiful of the Greek marbles. It is a nearly pure carbonate of lime of creamy whiteness, with a finely crystalline granular structure, and is nearly translucent. It may be readily distinguished from all other white marbles by the peculiarly sparkling light that shines from its crystalline facets on being freshly broken; and this peculiarity enables the expert at once to determine the origin of any fragment of Greek or Roman statuary. The ancient quarries in the island of Paros are still wrought, though very little marble from this source is exported to other countries. In the entablature around the tomb of Cæcilia Metella, which is composed of Parian marble, we see the first example in Rome of the use of ornaments in marble upon the outside of a building; an example that was afterwards extensively followed, for all the tombs of a later age on the Appian Way had their exteriors sheathed with a veneer of marble. The beautiful sarcophagus which contained the remains of the noble lady for whom this gigantic pile was erected, and which is now in the Farnese Palace, was also formed of this material. Most beautiful examples of Parian marble may be seen in the three elegant columns of the Temple of Castor and Pollux in the Roman Forum, belonging to the best period of Græco-Roman architecture; and in the nineteen fluted Corinthian pillars which form the little circular temple of Hercules on the banks of the Tiber, long supposed to be the Temple of Vesta. By far the largest mass of this marble in Rome is the colossal fragment in front of the Colosseum that belonged to the Temple of Venus and Rome; and it helps to give one an idea of the extraordinary grandeur and magnificence of this building in its prime, whose fluted columns, six feet in diameter, and the sheathing of whose outside walls of great thickness, were all made of Parian marble.

More extensively employed in Greek and Roman statuary and architecture was the _Marmor Pentelicum_, or Marmo Greco fino of the modern Italians. The quarries which yielded inexhaustible materials for the public buildings and statues of Greece, and for the great monuments of Rome, were situated on the slopes of Mount Pentelicus, near Athens; and after having been closed for ages, have recently been reopened for the restoration of some of the buildings in the Greek capital. The marble is dazzlingly white and fine-grained, but it sometimes contains little pieces of quartz or flint, which give some trouble to the workmen. The Parthenon, crowning like a perfect capital of human art the summit of Nature's rough workmanship in the Acropolis, was built of this marble; and the immortal sculpture of Pheidias on the metopes, the frieze of the cella, and the tympana of the pediments of the temple, known as the Elgin Marbles, were carved out of a material worthy of their incomparable beauty. Innumerable specimens at one time existed in Rome. The arch of Septimius Severus and the Arch of Titus are built of it, although the rusty and weather-beaten hue of these venerable monuments hides the nature of the material. Domitian, who restored the celebrated Temple of Jupiter on the Capitol, procured columns of Pentelic marble for the purpose from Athens; two of these are now in the nave of the church of Ara Coeli, built upon the site of the temple; and portions of the others, and of the marble decorations, were presented by the magistrates to the Franciscan friars of the neighbouring convent, and by them were wrought in 1348 into the conspicuous staircase leading to the façade of the church, which pious Catholics used to mount on their knees in the manner of the ancient worshippers of Jupiter. Among the statues wrought of this marble may be mentioned the famous group of the Laocoon found in the Baths of Titus; the beautiful Venus de Medici, discovered in the Villa of Hadrian, near Tivoli, and now in the Uffizi Gallery in Florence; and the well-known "Farnese Bull," sculptured out of a single block of huge dimensions, unearthed out of the ruins of the Baths of Caracalla, and now in the Museum of Naples. Massimo d'Azeglio, in his _Recollections_, gives an interesting instance of the value set upon this marble by modern Roman sculptors. Pacetti having purchased an ancient Greek statue of the best period in Pentelic marble, greatly mutilated, and wishing to repair it, could find nothing among the best products of the Carrara quarries to match the marble in purity and fineness of texture, and was therefore obliged to destroy another Greek statue of inferior merit in order to get materials for the restoration. From this combination he succeeded in producing the sleeping figure known as the Barberini Faun, whose forcible abduction by the Pontifical Government on the eve of its being sold to a German prince, so preyed upon the mind of the cruelly-wronged sculptor, that he took to his bed and died.

Very like Pentelic marble, but easily distinguishable, is the Marmor Porinum, the Marmo Grechetto duro of the Italians. It is intermediate in the quality of its grain between Parian and Pentelic marble, being finer than the former and not so fine as the latter. The column in front of the Church of Santa Maria Maggiore, removed by Paul V. in 1614 from the Basilica of Constantine, is composed of this species; as well as the celebrated Torso Belvedere of the Vatican, found near the site of the Theatre of Pompey, to which Michael Angelo traced much of his inspiration, and which, as we learn from a Greek Inscription at the base, was the work of the Rhodian sculptor Apollonios, who carved the group of the "Farnese Bull."

Not unlike this Porine marble was the _Marmor Hymettium_ of the ancients; but it was never a great favourite in Rome on account of its large grain and dingy white colour, slightly tinged with green and marked by long parallel dark gray veins of unequal breadth. The metamorphic action was not sufficiently energetic to destroy the last traces of organic matter and the original stratification of the rock; and the crystallising force was not sufficiently exercised to allow of the entire rearrangement of the whole of the particles so as to expel the included impurities. This marble was not therefore fitted for sculpture; but it could be used for certain architectural purposes and for ornamentation. It used to be quarried extensively on Hymettus, the well-known mountain of Attica, celebrated for the quantity and excellence of its honey. The rock on which the aromatic flowers grew in such profusion for the bees, did not, however, partake of the same delightful quality. In working it a peculiar fetid odour of sulphuretted hydrogen, somewhat like that of a stale onion, was emitted, which gave rise to its modern Italian name--Marmo Cipolla. This repulsive quality, however, disappeared quickly on exposure. The finest specimens of this marble in Rome are the forty-six columns in the Church of St. Paul's, outside the gate, which belonged originally to the Basilica Æmilia in the Forum, founded about forty-five years before Christ, and were transferred to the new building when the venerable old church, in which they had stood for fifteen hundred years, was destroyed by fire. Nothing too can be finer than the two rows of Ionic columns of Hymettian marble which divide the immense nave of Santa Maria Maggiore from the side aisles. There are eighteen on either side, each upwards of eight feet in circumference, and are supposed to have been taken from the Temple of Juno Lucina, whose site is assigned by antiquaries to the immediate vicinity. Similar rows of fluted Doric columns of the same marble, ten on each side, adorn the Church of St. Pietro in Vincoli. They are ancient, and belonged to some temple or basilica of the Forum. There are also five ancient pillars of Hymettian marble in the upper Church of San Clemente, taken from the same prolific source. The wall which surrounds the unique choir or presbytery of this most interesting old church is also composed of great slabs of Hymettian marble, taken from the original subterranean church and hastily put together. Some of the ancient pillars of Hymettian marble belonging to the peristyle of the temple of Ceres and Proserpine, still as widely spaced as they used to be, adorn the Church of Santa Maria in Cosmedin, built on the foundation of that shrine; while twenty-four remarkably fine fluted Corinthian columns of the same material divide the triple nave of Santa Sabina on the Aventine, and are supposed to have belonged to the ancient Temple of Juno Regina, erected by Camillus after the destruction of the Etruscan city of Veii. Hymettian marble was one of the first--if not actually the first--species introduced into Rome. In the year of Rome 662, Lucius Crassus the orator brought to the city six columns of it, each twelve feet in height, with which he adorned his house on the Palatine Hill, receiving, on account of this circumstance, from Marcus Brutus the nickname of the Palatine Venus. At the present day the marble is used for corner-stones in the ordinary houses of Athens.

Another livid white marble, somewhat resembling the Hymettian, is that which is known to the Italians as Marmo Greco livido. It was called by the ancients _Marmor Thasium_, from Thasos, now Thapso, an island in the north of the Ægean Sea, off the coast of Thrace. The marble dug from the rocky sides of Mount Ipsario--a romantic hill thickly covered with fir trees, and rising three thousand four hundred and twenty-eight feet above the sea--enjoyed considerable reputation among the ancients. In Rome it must have been very common, if the name of Thasian is to be given to all the fragments of nondescript dusky white marble which are found among the ruins. Seneca says that the fish-ponds in his day were formed of that Thasian marble, with which at one time it was rare to adorn even temples. It was considered the least valuable of the white Greek marbles, and was used for the more ordinary purposes; Statius mentioning, in order to show the surpassing splendour of a particular building, that Thasian marble was not admitted into it. But there are not many well-defined monuments of it remaining in Rome. The chief are the bust of Euripides in the Vatican, and the outside casing of the pyramid of Caius Cestius, near the Protestant cemetery, now so weather-beaten and stained with dusky lichens that it is difficult to identify the material of which it is composed.

From this marble, by a slight tinge of yellow and a little darker shade, the livid white marble of Lesbos, the _Marmor Lesbium_, or Marmo Greco Giallognolo, may be distinguished. It is not a beautiful material; and yet, strange to say, the statues of some of the most beautiful women of antiquity, such as those of Julia Pia in the Vatican, and of the Capitoline Venus in the Museum of the Capitol, were made of this marble, obtained from the birthplace of Sappho. More beautiful is the kind known as the _Marmor Tyrium_, or the Greco-Turchinicchio, which has a light bluish tinge. It was shipped by the ancients at the port of Tyre from some unknown quarry in Mount Lebanon, which supplied the marble used without stint in the building and decoration of Solomon's Temple and Palace. In this quarry every block was shaped and polished before it was sent to be inserted in its place in the Temple wall, which therefore, as Heber beautifully says, sprang up like some tall palm in majestic silence. In Rome this marble was very rare. The doors in the great piers which support the dome of St. Peter's are each flanked by a pair of spirally-fluted columns of Tyrian marble, supposed to have been brought to Rome by Titus from the Temple of Jerusalem. They originally decorated the confessional of the old Basilica. The twenty-eight steps of the Scala Santa at the Lateran, said by ecclesiastical tradition to have belonged to Pilate's house in Jerusalem, and to have been the identical ones which our Saviour descended when He left the judgment-hall, are made of this marble; so that, whatever we may think of the tradition itself, there is a feature of verisimilitude in the material.

The chief supply of pure white marble in Rome was derived from the quarries in the mountains at Luna, an old Etruscan town near the Bay of Spezia, which fell to decay under the later Roman emperors. This ancient _Marmor Lunense_ is called by the Italians Marmo di Carrara, because it is identical with the famous modern Carrara marble, and belongs to the same range of strata; the ruins of the ancient Luna being only a few miles from the flourishing town of Carrara, the metropolis of the marble trade. From Parian and Pentelic marble, Lunar marble, as already mentioned, can be easily distinguished by the less brilliant sparkle of its crystal facets, as shown by a fresh surface, and also by its more soapy-white colour. It is simply an ordinary Jurassic limestone altered by subsequent metamorphic action. The mountains which contain the quarries are highly picturesque, rising with serried outline to a height of upwards of five thousand feet, their flanks scarred by deep gorges and torrent-beds, and their lower slopes clothed with olive groves, vineyards, and forest trees. Lunar marble was first brought to Rome in the time of Julius Cæsar; and Mamurra, so bitterly reviled by Catullus, the commander of the artificers in Cæsar's army in Gaul, lined with great slabs of this marble the outside and inside of his house on the Coelian Hill--the first recorded instance of veneering or incrusting walls with marble. The discovery of this method of cutting marble into thin slices, and decorating structures of ordinary materials with them, was stigmatised by Pliny as an unreasonable mode of extending luxury. The use of Lunar marble, on account of its easy accessibility, speedily extended to every kind of building, public and private. So vast were the quantities sent to Rome, that Ovid expressed his fear lest the mountains themselves should disappear through the digging out of this marble; and Pliny anticipated that dreadful consequences would be produced by the removal in this way of the great barriers erected by Nature.

Many fine specimens still survive the ravages of ages, among which may be mentioned the eleven massive Corinthian columns, upwards of forty-two feet high, and four and a half feet in diameter, which form the peristyle of the Temple of Neptune in the Piazza di Pietra, well known as the old Custom-house. These pillars suffered severely from the action of fire, and are much worn and defaced, but there is a grandeur about them still which deeply impresses the spectator; and the blocks of marble which form the inner part of the architrave and entablature, as seen from the inner side of the court, are so stupendous that the ruins "overhang like a beetling rock of marble on a mountain peak." Grander still is the majestic column of Lunar marble dedicated to Marcus Aurelius, in the Piazza Colonna, which rears aloft its shaft one hundred and twenty-two feet in the air, wreathed around with spiral bands of historic reliefs, illustrating the Roman conquests over the German tribes north of the Danube. Very splendid specimens of the same marble may be seen in the three fluted Corinthian columns and a pilaster belonging to the Temple of Mars Ultor erected by Augustus in his Forum after the battle of Actium, which are the largest columns of any kind of marble in Rome, being eighteen feet in circumference, and upwards of fifty-four feet high. The two well-known pillars of the portico of the Temple of Minerva, called Le Colonnacce, belonging to the adjoining Forum of Nerva, are also composed of the same material; as also the three deeply-fluted Corinthian columns that remain of the Temple of Vespasian in the Roman Forum, which still retain some traces of the purple colour with which they appear to have been painted. By far the largest single masses of Lunar marble are the two portions of a gigantic frieze and entablature, highly ornamented with sculpture, one measuring one thousand four hundred and ninety cubic feet, and weighing upwards of one hundred tons, lying in the Colonna gardens on the slope of the Quirinal. These relics are supposed to have belonged to the splendid Temple of the Sun, which Aurelian erected after the conquest of Palmyra, and in which he deposited the rich spoils of that city. They are associated therefore with romantic memories of the famous Queen Zenobia, who spent her last days near Tivoli, after having been led captive in fetters of gold to grace the triumphal procession of her conqueror.

For statuary purposes Lunar marble was extensively used in ancient Rome. It formed the material out of which the sculptor produced some of the noblest creations of his genius. Of these the Apollo Belvedere in the Vatican collection is one of the most remarkable. The evidence of its own material, as already mentioned, has dispelled the old idea that it is one of the masterpieces of the Greek school; and Canova's conjecture, based upon some peculiarities of its drapery, is in all likelihood true, viz. that it was a copy of a bronze original, made, probably at the order of Nero, for one of the baths of the imperial villa at Antium, in whose ruins it was found in the fifteenth century. From the time of the Romans, the white marble of the Montes Lunenses has been used for decorative purposes in many of the churches and public buildings of Italy. It formed the material out of which Michael Angelo, Canova, and Thorwaldsen chiselled their immortal works. Its quality and composition, however, vary very considerably, and small crystals of perfectly limpid quartz, called _Carrara diamonds_, and iron pyrites, occasionally occur, to the annoyance of the sculptor. It becomes soon discoloured when exposed even to the pure air of Italy, but it is capable of resisting decay for very long periods. The opinion current in Paris, that the marbles of Carrara are unable to withstand the effects of the climate of that city, is due to the frequent use of inferior qualities, which are known to artists as _Saloni_ and _Ravaccioni_, and whose particles have but a feeble cohesion, and consequently slight durability.

All the white marbles which I have thus described were used in Rome principally for external architecture; and beautiful as a city largely built of them may have looked, it must have had, nevertheless, a garishness and artificiality which would offend the artistic eye. When newly constructed, the Roman temples in the time of the emperors must have been oppressive, reflecting the hot sunshine from their snowy cellæ and pillared porticoes with an insufferable glare. Marble--unlike sandstones, clay-slates, and basalts, which are kindred to the earth and the elements, and find themselves at home in any situation, all things making friends with them, mosses, lichens, ivies--is a dead, cold material, and does not harmonise with surrounding circumstances. Like the snow, which hides the familiar brown soil from us, with its unearthly and uncongenial whiteness, its perpetual snow chills and repels human sympathies. Nature, for a similar reason, introduces white flowers very sparingly into the landscape; and their dazzling whiteness is toned down by the greenery around them, and the balancing of coloured objects near at hand, so that they do not in reality attract more notice than other flowers. The ancient Greeks themselves, keenly sensitive as they were to all external influences, had a fine instinct for this want of harmony between white marble and the tones of nature and the feelings of man; and therefore, in many instances, they coloured not only the marble buildings exposed to view outside, but even the marble statues carefully secluded in the niches within. The Parthenon was thus tinted with vermilion, blue, and gold, which seems to us, who now see only the golden hue with which the suns of ages have dyed its pure Pentelic marble, a barbarous superfluity, but which, to the people of the time, was necessary on account of the dazzling brightness of its material, concealing the exquisite beauty of the workmanship, and the finished grace of its proportions. Colour was used with perfect taste to relieve the sculptured details of the exterior, to articulate and ornament mouldings, and to harmonise the pure white temple with the dark blue sky of Greece and the rich warm tones of her landscape. The magnificent sarcophagi of white marble recently discovered at Sidon, belonging to the best type of Greek art, are most effectively adorned with different tints and gradations of red and purple, gold being sparingly applied. We see many traces of bright colouring on the columns and other parts of the buildings in the Roman Forum. The bas-reliefs on the Lumachella marble of Trajan's Column were originally picked out with profuse gilding and vivid colours; the egg and arrow moulding of the capital being tinted green, red and yellow, the abacus blue and red, the spirals yellow, the prominent figures gilt against backgrounds of different hues, and the water of the various rivers blue. Statues of the deities in Rome were nearly all coloured; and they received a fresh coat of vermilion--which, although it was the hue of divinity, was extremely fugacious--on anniversary occasions or in times of great national rejoicing.

All this pleads powerfully in behalf of Gibson's colour-creed, which has had so much prejudice to overcome. The beauty and expression of ancient sculpture, whether for outside or inside decoration, were greatly heightened by this tinting. In cases where it was not employed, Nature herself became the artist, and has burnt into the marble statue or the marble pillar the warm hue of life; and the rusty, withered look of the ruins, over which ages of change have passed, touches us more than the pure white marble structure could have done in the pride of its splendour, and appeals to the tenderest sympathies of beings who see in themselves, and in all around them, the tokens of death and decay. The graceful Corinthian pillars of the Temple of Castor and Pollux in the Forum, the three surviving witnesses of its former grandeur, are all the more suggestive to us by reason of the russet hues with which time has stained the snowy purity of their Parian marble; and it is difficult to say, as some one has shrewdly remarked, how much of the touching effect which the drooping figure of the Dying Gladiator of the Capitol produces upon us may be attributed to its discoloration, and to the absence of the dainty spotlessness of the original Greek marble. That grime of ages "lends a sort of warmth, and suggests flesh and blood," so that the suffering is not a cold and frosty incrustation, with which we have nothing to do, but a real tragedy going on before our eyes, by which our sympathies are most deeply moved. In a dry, hot climate, like that of Rome, there are no tender tones of vegetable colouring, no moss or lichen touches of gold or gray or green to relieve the bare cold surface, and the rigid formal outlines of the marble; but out of the sky itself the marble gathers the soft shadows and the rich brown hues that reconcile its strange, unnatural whiteness with the homely ways of the familiar earth. That wonderful violet sky of Rome would glorify the meanest object. The common red brick glows in its translucent atmosphere like a ruby; and the russet defaced column, as it comes out against its vivid light, becomes luminous like a pillar of gold. Brick and marble are of equal æsthetic value in this magic city, in which the uncomely parts and materials have a more abundant comeliness by reason of the medium through which they are seen. Over all things lingers permanently the transfiguring glow that comes to northern lands only in the afternoon. In that land it is always afternoon; the ruins bathe as it were in a perpetual sunset. The air is constantly flooded with a radiance which seems to transfuse itself through every part of the city, making all its ruinous and hoary age bright and living, forming pictures and harmonies indescribable of the humblest objects.

The white marbles hitherto described were principally for exterior use. But as Roman wealth and luxury increased coloured marbles were employed for internal decoration; and the effects which the Greeks obtained by the application of pigments, the Romans obtained by the rich hues of precious marbles incrusting their buildings, and durable as these buildings themselves. At first these rare materials were used with a degree of moderation, chiefly in the form of mosaics of small discs or cubes for the pavements of halls and courts. But at length massive pillars were constructed of them, and the vast inside brick surfaces of imperial baths and palaces were crusted over and concealed by slabs of rare and splendid marbles, the lines of which had no necessary connection with the mass behind or beneath. Carthage from the spoils of its temples supplied Rome with many of its rarest columns; and it is probable that not a few of these survive in the Christian basilicas that occupy the sites and were built out of the materials of the old Pagan structures. With the decay of the Roman Empire the use of coloured marbles in art increased, so that even busts and statues had their faces and necks cut in white and the drapery in coloured marble. It attained its fullest development in the Byzantine style, of which, as it appeals to the senses more by colour than by form, it is a predominant characteristic, necessary to its vitality and expression. The early Christian builders contemplated this mode of decoration for their interiors only. Very rarely had they the means to apply it to the outside surface, as in St. Mark's in Venice, which is the great type of the Byzantine church, coloured within and without with the rich hues of marbles and mosaics. Our great Gothic cathedrals, as an eminent architect has said, were the creation of one thought, and hence they were complete when the workmen of the architects left them, and their whole effect is dominated by one idea or one set of ideas; but the early Roman churches were the results of a general co-operation of associated art, and the large and plain surfaces of the interiors were regarded by the sculptor as a framework for the exhibition of his decorative art. Colour was lavished in veneers of rare marbles, and costly mosaics and frescoes covering the walls. There was thus "less unity of purely architectural design, but a greater amount of general artistic wealth."

Intermediate between the white marbles used for external architecture and the coloured marbles used for internal decoration, and forming the link between them, is the variety called by the Italians cipollino, or onion-stone. Its classical name is _Marmor Carystium_, from Carystos, a town of Euboea, mentioned by Homer, situated on the south coast of the island at the foot of Mount Oche. This town was chiefly celebrated for its marble, which was in great request at Rome, and also for its large quantities of valuable asbestos, which received the name of Carystian stone, and was manufactured by the Romans into incombustible cloth for the preservation of the ashes of the dead in the process of cremation. The asbestos occurs in the same quarries with this marble, just as this mineral is usually associated with talc schist, in which chlorite and mica are often present. Strabo places the quarries of cipollino at Marmorium, a place upon the coast near Carystos; but Mr. Hawkins mentions in Walpole's _Travels_ that he found the ancient works upon Mount Oche at a distance of three miles from the sea, the place being indicated by some old half-worked columns, lying apparently on the spot where they had been quarried. This marble is very peculiar, and is at once recognised by its gray-green ground colour and the streaks of darker green running through the calcareous substance like the coats of an onion, hence its name. These streaks belong to a different mineral formation. They are micaceous strata; and thus the true cipollino is a mixture of talcose schist with white saccharoidal marble, and may be said to form a transition link between marble and common stone. It belongs to the Dolomitic group of rocks, which forms so large a part of the romantic scenery of South-Eastern Europe, and yields all over the world some of the best and most ornamental building-stones. In this group calc-spar or dolomite wholly replaces the quartz and films of argillaceous matter, of which, especially in Scotland, micaceous schist is usually composed. There are many varieties of cipollino, the most common being the typical marble, a gray-green stone, sometimes more or less white, with veins of a darker green, forming waves rippling over it like those of the sea. It occurs so often among the ruins that it must have been perhaps more frequently used in Rome than any other marble. It was also one of the first introduced, for Mamurra lined the walls of his house on the Coelian with it, as well as with Lunar marble, in the time of Julius Cæsar; but Statius mentions that it was not very highly esteemed, especially in later times, when more valuable marbles came into use.

One remarkably fine variety called _Cipollino marino_ is distinguished by its minute curling veins of light green on a ground of clear white. Four very large columns in the Braccio Nuova of the Vatican, which may have belonged originally, like the two large columns of _giallo antico_ in the same apartment, to some sumptuous tomb on the Appian Way, are formed of this variety, and are unique among all the other pillars of cipollino marble to be seen in Rome for the brightness of their colour and the exquisite beauty of their venation. Nothing can be more striking and beautiful than the rich wavelike ripples of green on the cipollino marbles that encase the Baptistery of St. Mark's in Venice, as if the breakers on the Lido shore had been frost-bound before they fell, and the sea-nymphs had sculptured them into the walls of this "ecclesiastical sea-cave." Indeed all the outside and inside walls of the glorious old church are cased with this marble--in the interior up to the height of the capitals of the columns; while above that, every part of the vaults and domes is incrusted with a truly Byzantine profusion of gold mosaics--fit image, as Ruskin beautifully says, of the sea on which, like a halcyon's nest, Venice rests, and of the glowing golden sky that shines above it. Line after line of pleasant undulation ripples on the smooth polished marble as the sea ebbs and flows through the narrow streets of the city. In the churches and palaces of Rome specimens of all the varieties of cipollino may be found, taken from the old ruins, for the marble is not now worked in the ancient quarries. The largest masses of the common kind in Rome are the eight grand old Corinthian columns which form the portico of the Temple of Antoninus Pius and Faustina in the Forum. The height of each shaft, which is composed of a single block, is forty-six feet, and the circumference fifteen feet. The pillars look very rusty and weather-worn, and are much battered with the ill-usage which they have received.

One of the most beautiful and highly-prized marbles of ancient Rome was the species which is familiar to every visitor under the name of _Giallo antico_. It must have existed in immense quantities in the time of the emperors, for fragments of it are found almost everywhere, and it is the variety that is most frequently picked up and converted into ornamental articles. It is easily recognised by its deep brownish-yellow colour, resembling somewhat the yellow marbles of Siena and Verona, though invariably richer and brighter. All the varieties are traversed more or less by veins and blotches of a darker yellow or brownish hue, which give them a charming variety. The texture is remarkably fine and close-grained. In this respect _giallo antico_ can be distinguished from every other marble by the touch. When polished it is exquisitely smooth and soft, looking like ivory that has become yellow with age. No fitter material could be employed for the internal pavements or pillars of old temples, presenting a venerable appearance, as if the suns of many centuries had stained it with their own golden hue. From the fact that it was called by the Romans _Marmor Numidicum_, we are led to infer that this marble was quarried in Numidia, and was brought into Rome when the region was made a Roman province by Julius Cæsar. It was probably known to the Romans in the time of Jugurtha; but the age of luxury had not then begun, and Marius and Sulla were more intent upon the glories of war than upon the arts of peace. The quarries on the slopes of the Atlas, worked for three hundred years to supply the enormous demand made by the luxury of the masters of the world, were at last supposed to be exhausted; and the idea has long prevailed that the marble could only be found among the ruins of the Imperial City. But four or five years ago, the sources from which the Romans obtained some of their most precious varieties of this material have been rediscovered in the range of mountains called Djebel Orousse, north-east of Oran in Algeria. All over an extensive rocky plateau in this place numerous shallow depressions plainly indicate the existence of very ancient quarries. A large company has been formed to work and export the marble, which may now be had in illimitable quantity. The largest specimens of _giallo antico_ existing in Rome are the eight fluted Corinthian pillars, thirty feet high and eleven feet in circumference, with capitals and bases of white marble, which stand in pairs within the niches of the Pantheon. In consequence of the fires of former generations, the marble has here and there a tinge of red on the surface. In the Church of St. John Lateran there is a splendid pair of fluted columns of _giallo antico_, which support the entablature over a portal at the northern extremity of the transept. They are thirty feet in height and nine feet in circumference, and were found in Trajan's Forum. In the Arch of Constantine are several magnificent _giallo antico_ columns and pilasters, which are supposed to have belonged to the triumphal arch of Trajan. They are so damaged in appearance, and so discoloured by the weather, that it is not easy, without close inspection, to tell the material of which they are composed. For pavements and the sheathing of interior walls _giallo antico_ was used more frequently than almost any other kind of marble; hence it is mostly found in fragments of thin slabs, with the old polish still glistening upon them.