Orvieto Cathedral is, on a smaller scale, similar to the neighbouring cathedral of Sienna. The West front is designed with most elaborate detail and highly ornamented with painting and sculpture. The Duomo of Florence partakes also of the general characteristics of Sienna, although its proportions are vastly larger. Its most striking feature is the great dome, added by Brunelleschi, when the church, designed by Arnolfo, was approaching completion; but it is unsatisfactory, as its immense size dwarfs the rest of the building. The general picturesqueness of outline, the delicate design of the doors and windows, and the proximity of the beautiful tower of Giotto, go far to atone for this. The exterior walls of the church are covered with a veneering of coloured marbles, which, while judiciously treated and good of its kind, is too false to be easily reconciled to true artistic principles, and its skin-deep beauty has been painfully apparent, until very recently, owing to the unfinished condition of the West front. It may be said in extenuation of this that plaster, while generally accepted as an honest material, is no less a shallow covering to disguise naked walls; it is, however, frequently misused, and is only tolerable so long as it is not employed in imitation of better materials, while the thin marble is really intended to deceive the eye, and give the impression that its depth is equal to that of the wall. The interior of the Florence Cathedral is disappointing, it is insufficiently lighted, bare, and much in need of the frescos with which it was originally intended to be decorated. The cathedral of Pisa belongs in greater part to the preceding style, but the campo-santo adjoining it has a cloister with traceried windows, which, notwithstanding its round arches, more nearly resembles Northern Gothic than anything in Italy, and by its greater height shows a novel and more effective treatment than is usually seen in France or England. The little church of St. Maria della Spina in this town, on the banks of the Arno, is a charming little edifice of the Sienna type. In civil architecture Italy has much to boast of. Her palaces and fortresses are amongst the noblest and most picturesque buildings of the Middle Ages found anywhere in Europe. Most of these are rectangular masses of stone, the austerity of which is relieved by heavy window-openings with pointed heads and moulded frames, and crowned by a battlemented cornice, occasionally enlivened by shields placed between alternate corbels. The addition of the campanile, used as a lookout tower rather than as a belfry, generally completes an imposing structure.