( Originally Published 1920 )
MAN'S earliest attempts at decoration were by the incised method applied to the walls of his cave, as well as the sides of the great monolithic stones he used in worship, which he adorned with dots, rings, circular cup-like hollows and curving lines. But when mud walls began to be built, frequently with courses of stone or wattle-work peeping out, the desire to ornament them with bands of shells, patches of coloured stones stuck in the soft material (just as we see to this day in the flint-faced cottages of East Anglia) must have been irresistible. It is probably in this way that the art of using small pieces of contrastingly coloured stone, bedded in the surface of a building in order to produce a pattern, originated. At all events, specimens of this style, even of a refined character, go back to remote periods in Egypt, and Layard found ivory and gold tesseræ in Nimroud.
Pliny, mentioning the use of mosaics in Rome, says that Scylax first introduced " stone-laid work " about 80 B.C. It rapidly spread, and from the time of Constantine the Great (A.D. 320) onward the art assumed enormous importance, both on account of the frequency with which its aid was sought in embellishing public and private buildings, and the high perfection in design and execution to which it was brought.
Of the making of mosaics, as we have said, there are, if not endless, certainly many ways. If the Egyptians and Assyrians employed small regularly shaped cubes, in Rome and other places squares and oblongs, triangular and circular pieces, pentagons, hexagons, octagons and other geometrical figures were called into service, and much effective work was accomplished with small and large irregularly shaped pieces. Moreover, the contrasting materials differed widely both as regards periods and locality. We find the Romans adorning the vaults and ceilings of the Baths of Caracalla with plain black and white mosaics. In some cases the ceiling was framed round with lines and foliage, then the whole surface divided up into big oblong panels with intersecting small circles and squares, the oblongs containing coarsely drawn gigantic figures of athletes very spirited in appearance, the smaller panels filled in with laurel wreaths, a discus or other article used in the circus and training school. Such simple contrasts scarcely satisfied the taste for luxury, and so both large and small tesseræ of coloured marbles, alabaster, and other costly stones rapidly came into fashion and long remained popular, though component parts often differed according to locality. This adaptation of materials close at hand for decorative purposes is quaintly and strikingly illustrative in the volcanic mosaics. In these cases, lava of different shades is cut into thin slabs, divided into cubes, or broken up into irregular fragments, the fine grained surface being highly polished, and then, imbedded in plaster, elaborate designs produced. Perhaps the best specimens of this style are to be seen on the Duomo and great cloisters of Monreale in Sicily, constructed out of lava belched forth from Etna and brought in a molten flood to the very hands of the designers. Other notable examples are to be seen in the churches of Amalfi and Ravello from the lava cast out from Vesuvius, and in those of the puy-du-Dome from material deposited in past ages by long since extinct craters. Another school, that of the Easternised Greeks of Byzantium, fired by the sensuous glories of Asia, added glass as a predominating material, thus introducing the most vivid colours, scintillating effects, and the marvellous foil of gold beneath clear or tinted vitrious glazes. A variation on this is introduced with the use of small self-coloured glazed tiles, or tiles decorated with filigree patterns.
Ciampini, who has probably written most fully and learnedly upon the subject, divides the art of mosaic into four great classes. Tesselatum consists of small cubes of marble in. square (tesserae), usually black and white and worked into geometrical patterns, and sectile is composed of slices of marble (sectilia), generally employed to produce broad effects, rarely for elaborate subjects. Both of these, our author puts down as pavement work. But, as we have seen, black and white mosaics were used in the vaulted roofs of the Baths of Caracalla. The third class is figilnum, known in Italy as lavoro di smalto, fictile work, composed of very small fragments of a compound of silica and alumina, coloured by oxides, and, of course, produced in the glass-maker's furnace. In this way, any colour can be obtained, with great brilliance and softness. This is used on walls and vaulted spaces. Vermiculatum is a mixture of cubes of coloured marbles (figilnum), gold beneath enamel, and even precious stones employed to produce complete pictures, with human figures, animals, plants and so on in their natural colour. This, too, is for adorning walls and ceilings. A fifth class is the opus Grecanicum, consisting of incrustation in grooves cut in white marble, or other stone, of tiny cubes of coloured and gilded smalto, together with cubes of serpentine, porphyry and other costly materials. It is usually handled to produce conventional and geometrical designs, in thin ribbons, broad bands or smallish panels, outlining the semi-circle of an arch, or embellishing its intrados, ringing the capital of a pillar, emphasising a window or lending colour and distinction wherever most needed. Opus Grecanicum was used to outline the entablature, arches and capitals at San Lorenza-fuori-Mura, Rome, while in the cloisters of San Giovanni Laterano the variously shaped columns—circular, octagonal and twisted—are adorned with this form of mosaic in vertical bands or in spirals.
As regards style, the Roman mosaics were employed chiefly in carrying out geometrical and conventional designs, though natural objects were by no means excluded, as we see by the above mentioned athletes, and as we know from that chained house dog, " Cave Canum," found at Pompeii and reproduced in all kinds of materials ad nauseam for many years past. In the early days their first work seems to have been reserved for pavements, and also for conventional mural and vault decoration. When natural objects were attempted, coarse work is the rule, as this appears to be most effective when seen at a distance, more especially when placed at a considerable height. Serlio gives reproductions of some very fine, exquisitely conceived mosaics from the temple of Bacchus and the Baths of Diocletian, which was mixed with carved stone and stucco work in the vaults.
Originally Byzantine work had strong traces of the Roman and Grecian love of conventional incidental decoration, though expanding in the luxuriancy of the Orient. Nevertheless the religious sentiment prevailed, and the Byzantine artists in mosaics also set the law in this for the whole of medieval Europe, and employed their art largely to depict natural objects suitable to adorn their basilicas. The rich cubes are imbedded in cement covering the walls and vaults. Pictures usually have a background of gold tesserte, and are elaborately framed with conventional line or foliated designs. Specimens of this work are to be seen almost all over Europe, but the best adorned are the Cathedral of San Marco and other churches in Venice, where the art was carried to a pitch of perfection. In Sicily, and certain Southern Italian towns, the Byzantine mosaics have a peculiar character, apparently influenced by Saracenic taste. Wonderful specimens are to be seen in the Cathedral of Monreale, near Palermo, which, with its precincts, is lavishly enriched with mosaics of the polychrome vermiculatum and the monochrome volcanic types. The most celebrated is the half-figure of our Saviour, greatly exceeding life size, shown in the act of benediction in accordance with Roman ritual, which occupies the semi-dome of the apse. Vivid colours are used, and the background is of the characteristic broken gold type. The tesseræ are rather large and of irregular outline.
With the Renaissance freedom was sought from the rich yet austere formalism of Byzantium. Michel Angelo, was among the chief of Christian emblems, symbolising the Saviour. This work is a mixture of coarse tesselatum and fine vermiculatum.
The Turks in Constantinople and Asia Minor modestly, but effectively enough, carried on the Byzantine traditions by employing rather large pieces of glazed earthenware. In Persia—where, indeed, mosaic seems to be indigenous. judging from the very ancient, very persistent and commonly used form of decoration on pottery, graven and enamelled metal vessels, stitchery, and so on ; the mosaic work is carried out by means of small, highly glazed bricks, with occasional resort to a large piece of faience. The Mauresque style admits both a modified form of the Byzantine fictile, and the use of fairly large tiles impressed with deep cut, very intricate geometrical and knot tracery patterns. these being smeared over with Raphael and other foremost artists of the day designed set pictures, and decorative pieces for mosaic work in churches, ecclesiastical and other buildings. They painted in mosaic as they painted in fresco or oils, and if they adopted some of the exuberant grotesques and other accessories from antiquity, they discarded the older style of the Latins of outlining by means of a series of rectangular steps, such as we see in needlework tapestry, a memento of the' large square cubes. Very beautiful work, was produced under these masters and their successors, in which, however, occasionally naturalism jostles somewhat incongruously with weird arabesque fantasies. Naturalism, how-ever, was not altogether neglected by the men of old ; witness the huge spreading vine incrusting the whole vault of the baptistry dedicated by Constantine to Santa Costanza, which stands near the basilica of Sant' Agnesi-fouri-le-Mura. It conveys the idea of a pergola in some monastery or country villa, although amidst its leaves are introduced numerous symbols of Christianity. The vine itself, of course, made of clay, squeezed into moulds of different shapes, glazed, and then fired (baked). The edges were slightly bevelled to facilitate removal and give a good key.
In India a particular school of mosaic art seems to have had its centre at Agra and Delhi. It is said to be foreign to the country, imported by Italian workers imbued with the Byzantine feeling. If so, the Indians knew how to accept a good thing and make it their own. But there is much-in native decoration both of architecture and in the enamelling of metals that suggests a much older origin. Indian mosaic consists of an incrustation of very small pieces of marble, jasper, agate, blood-stone and other precious stones, placed very close together. It is fine work, almost luscious in colouring. The designs are good, but quite Hindu in feeling, with practically no attempt to copy nature, though with an underlying hint of Bordeaux, and here we have a certain admission of birds and figures. In the Taj Mahal the spirit is Asiatic, the spandrels, angles and more important details being incrusted with mosaic in precious stones, arranged in wreaths, scrolls and frets. Indeed, looking at the glowing bands of mosaics, it is difficult not to believe that the root idea of this embellishment is derived from the festal garlanding of persons and shrines with flora of the country. It must be remembered that Indian gardens and forests are green caskets afire with crimson and gold flowers, softened by sky-blue blooms and waxen white petals. Sir George Bird-wood, writing of the red silk cotton tree, says he " came upon a grassy glade over-hanging the profound forest depths below, and there, at its furthest edge, stood a colossal specimen of this tree, quite fifty feet high, the trunk straight as the mast of some great ammiral, deeply buttressed at its base, and sending out horizontal branches, like the yard-arms of a ship, in whorls of five and seven, gradually tapering to the top, and at this season—the month of March—leafless, but covered on every branch, in place of green leaves, with huge crimson flowers (by reflected light crimson ; by transmitted, the radiant red of a ruby), each from seven to five inches in diameter, and forming in the mass a vast dome-like, symmetrical head that, with the beams of the rising sun striking through it, shone in its splendour of celestial, rosy red like a mountain of rubies." He also speaks of the golden flowered bava, the purple taman, vermilion chrome yellow flowered pulas, the scarlet pangri, all fine trees. Then there are the oleanders and rhododendrons, the roses and jasmines, and hundreds more, both big and little. With all these wonders of nature about them, is not a jewelled style of decoration the most obvious and appropriate, whether on ceilings, on handsome vessels, or personal raiment?
Necessarily, practice in laying mosaics differs rather widely according to the materials used. Indian mosaic, like the riches of vermiculatum, is made up of small pieces, and these are imbedded in the cement so as to form a close jointing, the aim being to produce an effect of fine embroidery or cloisonné enamelling. Considerable mixture of colours is the rule, although blue, red, or yellow may be the prevailing hue, white and the other colours being placed in small dots here and there to give the jewelled effect.
Tile work also requires careful jointing, but here colour is more mixed.
With mural and ceiling work in Europe of the medieval period, and subsequently, a distinct aim is shown to produce a glowing, animated picture. Colour is used as in ordinary painting, and even shading is admitted. Flatness is redeemed by breaking up of the surface by cubes. No attempt is made to conceal joints by bringing pieces close together or staining the cement stopping. Indeed, perhaps the majority of the best specimens, old and new, are quite coarse in execution. If the mosaics of Chigiana Chapel in Santa Maria del Popolo, those of St Peter's in Rome, and those upon the dome of London's St Paul's (respectively fifteenth and nineteenth century work) be examined, it will be seen that the jointing is very wide. On the other hand, grouping and drawing are as perfect as they can be. This is right, for they are meant to be looked at from a distance ; they are essentially brightening motives in a general scheme of decoration. Now, under these conditions wide jointing and other lack of finish is not seen, indeed, too elaborate a finish would, under certain light conditions, produce the effect of mere flat washes of colour. But the quality of grouping and drawing is easily appreciated from a distance, and some regard to perspective must be paid. The best artists always emphasise drawing by outlining all profiles with a row of tesseræ of the same material and colour as the background. This throws up the figures, while it pre-vents the outline being broken upon by the horizontal or vertical lines of the back-ground, which would destroy much of the effect.
While mosaic is commonly employed to give brilliancy, to bring light into dark places, it is also exceedingly useful when carefully handled to correct defects of planning and construction. Horizontal lines give length and breadth, vertical lines give height. This is true whether bands or panels are selected by the designer. Quite happy results may be achieved when decorating a ceiling if this is borne in mind, while for adorning cupolas this method is invaluable. The very structure of mosaic decoration is an aid to training the vision in the way desired, emphasising the general flow of the design This holds good with all schools of mosaic, though, of course, it is most marked when small tesseræ are the medium.