Roman Mosaics; Or, Studies in Rome and Its Neighbourhood

by Hugh Macmillan

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.

It is difficult to describe, so as to identify it, the species of marble known as Africano. It has a great variety of tints, ranging from the clearest white to the deepest black, through yellow and purple. Its texture is very compact and hard, frequently containing veins of quartz, which render it difficult to work. Its ancient name is Marmor Chium, for it was brought to Rome from a quarry on Mount Elias, the highest summit in the island of Chios—the modern Scio—which contested the honour of being the birthplace of Homer. It received its modern name of Africano, not from any connection with Africa, but from its dark colour. It enters pretty frequently into the decoration of the Roman churches, though it is rare to see it in large masses. It seems to have been much in fashion for pavements, of which many fragments may be seen among the ruins of Trajan's Forum. The side wall of the second chapel in the Church of Santa Maria della Pace in the Piazza Navona is sheathed with large slabs of remarkably fine Africano, "with edges bevelled like a rusticated basement." In the Belvedere Cortile in the Vatican is a portion of an ancient column of this marble, which is the most beautiful specimen in Rome; and the principal portal of the portico of St. Peter's is flanked by a pair of fluted Roman Ionic columns of Africano, which are the largest in the city.

Closely allied to this marble is an ancient species which puzzles most visitors by its Protean appearance. Its tints are always neutral, but they vary in depth from the lightest to the darkest shade, and are never mixed but in juxtaposition. Dirty yellows, cloudy reds, dim blues and purples, occur in the ground or in the round or waved blotches or crooked veins. It has a fine grain and a dull fracture. This variety of Africano is known by the familiar name of Porta Santa, from the circumstance that the jambs and lintel of the first Porta Santa—a Holy Door annexed by Boniface VIII. to St. Peter's in the year 1300—were constructed of this marble. The Porta Santa, it may be mentioned, was instituted in connection with a centenary jubilee, but afterwards the period of formally opening it was reduced to fifty years, and now it is shortened to twenty-five. On the occasion of the jubilee, on Christmas Eve, the Pope knocks three times with a silver hammer against the masonry with which it is filled up, which is then demolished, and the Holy Door remains open for a whole twelvemonth, and on the Christmas Eve of the succeeding year is closed up in the same manner as before. A similar solemnity is performed by proxy at the Lateran, the Liberian, and the Pauline Basilicas. In all these great churches, as in St. Peter's, the jambs and Lintel of the Holy Door are of Porta Santa marble. This beautiful material was brought from the mountains in the neighbourhood of Jassus—a celebrated fishing town of Caria, situated on a small island close to the north coast of the Jassian Bay. From this circumstance it was called by the ancient Romans Marmor Jassense. Near the quarries was a sanctuary of Hestia, with a statue of the goddess, which, though unprotected in the open air, was believed never to be touched by rain. The marble, the most highly-prized variety of which was of a blood-red and livid white colour, was used in Greece chiefly for internal decoration. It was introduced in large quantity into Rome, and there are few churches in which the relics of it that existed in older buildings have not been adapted for ornamental purposes. Among the larger and finer masses of Porta Santa may be enumerated two columns and pilasters which belong to the monument of Clement IX., in the Church of Santa Maria Maggiore, and which are remarkable for their exceedingly fine texture and the unusual predominance of white among the other hues; four splendid Corinthian pillars, considered the finest in Rome, in the nave of Sta. Agnese; the pair of half columns which support the pediment of the altar in the Capella della Presentazione in St. Peter's; and the basin of the handsome fountain in front of the Pillar of Marcus Aurelius in the Piazza Colonna, constructed by the architect Giacoma della Porta out of an enormous mass of Porta Santa found lying on the ancient wharf.

Frequent specimens of a beautiful marble known as Fior di Persico, from the resemblance of the colour of its bright purple veins on a white ground to that of the blossom of the peach, may be found in the Roman churches. It was much used for mouldings, sheathings, and pedestals, and also for floors. In the Villa of Hadrian large fragments of slabs of this marble may be found, which lined the walls and floors of what are called the Greek and Latin Libraries. The Portuguese Church in Rome has several columns of Fior di Persico supporting the pediments of altars in the different chapels; especially four pairs of fluted ones which adorn the two altars at the extremity of the nave, which are among the largest and finest in Rome. But the most splendid specimens of all are a pair of columns in the Palazzo Rospigliosi. The dado, eight feet in height, in the gorgeous Corsini chapel in the Church of St. John Lateran, is formed of large tablets of highly-polished Fior di Persico, and the frieze that surrounds the whole chapel is composed of the same beautiful material, whose predominance over every other marble is the peculiarity of this sanctuary. The ancient name of this marble was Marmor Molossium, from a region in Epirus—now Albania—which was a Roman province in the time of Pompey. It is associated with the celebrated campaigns in Italy of Pyrrhus, king of Epirus, in which Greece was for the first time brought into contact with Rome. The region in which the quarries existed was the most ancient seat of Pelasgic religion.

The infinite hues and markings of the coloured marbles have all been painted by Nature with one material only, variously proportioned and applied—the oxide of iron. The varieties of marble are mainly caused by the different degrees in which this substance has pervaded them. They are variable mixtures of the metamorphous carbonates of protoxide of iron and lime. And it is an interesting fact that there is a distinct relation between deposits of magnetic iron ore and the metamorphoses of limestones into marbles; so that this substance not only gives to the marbles their colouring, but also their texture. Even the whitest saccharoidal or statuary marble, which it has not coloured, it has created by the crystallisation of the limestone associated with it. And the marbles of the entire province of the Apuan Alps owe their existence to the large quantities of iron ore disseminated throughout them, which have exercised a great influence on the molecular modification they have undergone. The same changes have been produced on the limestones of Greece and Asia Minor by veins containing iron ore running through them.