Mosaic painting was for some time the rival of oil-painting. It was much esteemed at Venice, where the damp affected other kinds of painting. It was introduced unquestionably by the Greeks. It afforded work for several centuries in the decoration of the church of St Mark, commencing from the eleventh century.
This department of art was not without its jealousies. The Zuccati were charged by their rivals with having filled up deficiencies in their work with other painting, and though Titian vindicated them, and is supposed to have assisted them in designs, the Venetian government decreed that they should re-execute the work at their own cost, which nevertheless was not done. Mosaic workers did not always work from the designs of others; some, and these not inconsiderable, painters applied themselves to this art. There were great "secreti" in the working in mosaic, which even now may be useful. The most important of these of working in mosaic was that of Agnolo, the son of Taddeo Gaddi, who, in 1346, repaired some of the mosaics executed by Andrea Tafi in the roof of St Giovanni at Florence. He fixed the cubes of the glass so firmly into the ground, with a stucco composed of wax and mastic melted together, that neither the roof nor the vaulting had received any injury from water from the period of its completion until the time of Vasari. May not our slate and mortar system be happily superseded? Mrs Merrifield takes occasion to redeem from his prison, to which, in her preface to the translation of Cennino Cennini, she had condemned, that earnest old man, upon the authority of the subscription from the prison of the Stinche--showing that it was the domicile of the transcriber, not the author. Vasari asserts that Cennino Cennini, to whom the secret of mosaic work was transmitted from Agnolo Gaddi, left a treatise on the subject. No such work has been yet found; but as there are other MSS. of the author, the treatise may be yet forthcoming. There is an anecdote which shows there may be better gold than comes from the mint. Alesso Baldovinetto, who spared no pains to learn the best methods of working in mosaic, learned much of the art from a German traveller to whom he had given a lodging. Thus, having been well informed, he worked with great success. At eighty years of age, feeling the natural infirmities fast approaching, he sought a retreat in the hospital of St Paul. "It is related that, in order to insure himself a better reception, he took with him to his apartments in the hospital a large chest, which was thought to contain money; and, in this belief, the officers of the hospital treated him with the greatest respect and attention. But their disappointment may be imagined, when, on opening the chest, after the decease of the aged artist, they found nothing but drawings on paper, and a small book which taught the art of making the mosaics, (_Pietre del Musaico_) the stucco, and the method of working. At the present time, we should have considered this little book a greater treasure than the money which was so much desired." We here have another delightful passage from Vasari, which will readily be accepted as the old man's excuse. "It was no wonder that they did not find money, for Alesso was so bountiful, that everything he possessed was as much at the service of his friends as if it had been their own." The introductory remarks on mosaic may be well worth the builder's and architect's attention, now that great improvements have been made in the making of glass, and that it is rendered so cheap; whilst duty was according to weight, the great art was to make it as thin as possible, hence the greater nicety and expense in the manufacture. To make thick, strong, or, in the language of mosaic art, cubes of glass for ornamental purposes, and as a preservative from weather, is a desideratum of the present day.