MOSAIC AND PIETRA DURA. 429 qui site shading of the colors, the brilliant though softened effeot of the group of views, the atmosphere a~d sky of each mingling into the same ethereal tint, which relieved the eye and allowed it to rest with pleasure on the separate views: it was certainly a masterpiece. The author never left the Crystal Palace without passing by the table, which always excited fresh admiration. There. were two other mosaics, much laTger than the former, and different in style, that were remarkably fine specimens of workmam;hip: one was a copy of a celebrated picture, . by Guercino,-a St. John the Baptist; and the other a portrait of Pope Boniface the Second. A circular table, a square slab, and a picture represent­ ing a view of P:;estum, were likewise 'among the Roman mosaics in the London Exhibition. Dr. Chilton, of New York, has a beautiful Roman mosaic of the Pantheon, about three inches long. In the New York Exhibition, in 1853, the large pic­ ture of Pope Pia IX., in medallion size, was much ad­ mired. In the Paris Exhibition, in 1855, many large wOTksof Roman mosaics were exhibited; one in particular, belong­ ing to the Duke of Tuscany, required the constant work of fourteen years, and cost 700,000 francs. A large table in the rotU11da of the panorama, of rich and elegant Roman mosaic, cost 400.,000 ii'anes. The famous picture of the' Campo-vacino, in Rome, by Galand, cost the artist ten years' labor. Fietra dura, also' called Florentine mosaic, consists in the manufacture of hard stone inlaid in a slab of marble; they are, for the most part, of the quartz species, such as agates, jasper, chalcedony, carnelian, &c.; also, lapis lazuli, malachite, and aHsuch hard and colored minerals which, by their depth of color and brilliancy of lustre largely con· .