In the seventeenth century a decline set in. The late Renaissance has neither the severity of the early, nor the dignified richness of the mature time, but is extravagant; though at Rome examples of its extreme phase are not common. Maderno, who erected the west front of St. Peter's, and Bernini, who added the outer forecourt and also built the curiously designed state staircase (the _scala regia_) in the Vatican, are the foremost architects. To these must be added Borromini. The great Barberini Palace belongs to this century; but perhaps its most characteristic works are the fountains, some of them with elaborate architectural backgrounds, which ornament many of the open places in Rome. Few of the buildings of the eighteenth century in Rome, or indeed in Italy generally, claim attention as architectural works of a high order of merit. Before leaving central Italy for the north, it is necessary to mention the masterpiece of Vignola--the great Farnese Palace at Caprarola; and to add that in every city of importance examples more or less admirable of the art of the time were erected. VENICE, VICENZA, AND VERONA. The next great group of Renaissance buildings is to be found at Venice, where the style was adopted with some reluctance, and not till far on in the sixteenth century. At first we meet with some admixture of Gothic elements; as, for example, in the rebuilding of the internal quadrangle of the Ducal Palace. Pointed arches are partly employed in this work, which was completed about the middle of the sixteenth century. In the earlier palaces--which, it will be remembered, are comparatively narrow buildings standing side by side on the banks of the canals--the storeys are well marked; the windows are round headed with smaller arches within the main ones; the orders when introduced are kept subordinate; the windows are grouped together in the central portion of the front, as was the case with those of the Gothic palaces, and very little use is made of rusticated masonry. The Vendramini, Cornaro, and Trevisano Palaces conform to this type. To the same period belong one or two fine churches, the most famous being San Zacaria, a building with a very delicately panelled front, and a semicircular pediment in lieu of a gable; here, too, semicircular-headed openings are made use of. In many of these churches and other buildings, a beautiful ornament, which may be regarded as typical of early Venetian Renaissance, is to be found. It is the shell ornament, so called from its resemblance to a flat semicircular shell, ribbed from the centre to the circumference (Fig. 67). [Illustration: FIG. 67.--ITALIAN SHELL ORNAMENT.]