In modern times, great attention has been bestowed to revive and improve the art, with a view to perpetuate the works of the great masters. In this way, Guercino’s Martyrdom of St. Petronilla, and Domenichino’s Communion of the dying St. Jerome, in St. Peter’s Church, which were falling into decay, have been rendered eternal. Also, the Transfiguration of Raffaelle, and other great works. Pope Clement VIII. had the whole interior dome of St. Peter’s ornamented with this work. A grand Mosaic, covering the whole side of a wall, representing, as some suppose, the Battle of Platea; as others, with more probability, one of the Victories of Alexander, was discovered in Pompeii. This work, now in the Academy of Naples, is the admiration of connoisseurs and the learned, not only from its antiquity, but from the beauty of its execution. The most probable supposition is, that it is a copy of the celebrated Victory of Arbela, by Philoxenes. Vasari says that the art of Mosaic work had been brought to such perfection at Venice in the time of the Bianchini, famous mosaic painters of the 16th century, that “it would not be possible to effect more with colors.” Lanzi observes that “the church and portico of St. Mark remain an invaluable museum of this kind of work; where, commencing with the 11th century, we may trace the gradual progress of design belonging to each age, up to the present, as exhibited in many works in mosaic, beginning from the Greeks, and continued by the Italians. They consist chiefly of histories from the Old and New Testaments, and at the same time, furnish very interesting notices of civic and ecclesiastical history.” There are a multitude of mosaic pictures in the churches, galleries, and public edifices of Italy, especially at Venice, Rome, Florence, Milan; and some of the greatest artists were employed to furnish the designs. In delicate ornamental work, the pieces are multiplied by sawing into thin slabs. Some specimens made of precious stones, are of incredible value. In working, the different pieces are cemented together, and when dry the surface is highly polished, which brings out the colors in great brilliancy. The ancients usually employed different colored marbles, stones, and shells; the Italians formerly employed brilliant stones, as agate, jaspar, onyx, cornelian, &c., but now they employ glass exclusively. THE OLYMPIAN JUPITER. The Greek masters in sculpture have been happily designated as “Magicians in Marble.” The taste which the Grecian people possessed for the beautiful, is well known. It stands among the chief of those characteristics by which they designated persons of great eminence. Their artists considered beauty as the first object of their studies; and by this means they surpassed all other nations, and have become models for all ages.