ARCHITECTURE 661 Olympius. The baths or therma of Augustus, Nero, Titus, Caracalla, and Diocletian were re- nowned for a magnificence which was hardly surpassed even by their palaces. In fact, throughout all the Roman structures, from the palace of the Caesars to the villas of Lucullus, Sallust, and Hadrian, the greatest display of splendor and luxury prevailed. But, of all their structures, perhaps the most stupendous was the Colosseum, capable of containing more than 100,000 spectators. It was partially destroyed in 1084, by Robert Guiscardthe Norman, who conceived the idea that it was to be used as a citadel against him. Though from the ruins the popes have taken sufficient material to construct the Farnese palace, the Cancella- ria, and St. Mark, the cragged and crumbling remains are still gigantic and imposing. V. AECHITECTUEE OF THE MIDDLE AGES. The architecture of this period, although it was derived from Greek and Roman models, applied new principles, forming, structures wholly different from the antique originals. Through many successive centuries the Ro- man school of art continued to suffer changes. From the fragments of edifices which were torn down to form new structures, arose new combinations. The transition styles which then prevailed were, from their characteristic peculiarities, designated as the Latin, the By- zantine, the Lombard, the Saxon, the Norman, and the Romanesque, together known as the old or round-arched Gothic. During the 4th century architecture had reached its lowest point. In the religious edifices of this period marked evidences exist of an utter want of artistic feeling. The sterling principles which had been the glory of Grecian and Roman schools were either forgotten or not under- stood. Arches with and without archivolts were made to spring immediately from the capitals of the columns. Orders were super- imposed with broken entablature ; in fact, this latter member was altogether done away with in some cases. Grace was wanting in the mouldings and sculpture ; the different orders were employed in the same peristyle, and the whole school of architecture became a prey to the general system of innovation which then existed. During this state of things hordes of barbarians invaded every province of the em- pire. This universal conflict was not calculated to give a new impetus to art, nor to promote its progress. Italy, however, under the rule of the Ostrogoths, evinced in some measure a renewed architectural zeal. Theodoric re- paired the walls and drains of Rome, reorgan- ized the comitivcB Romanes (who guarded day and night the monumental structures of the capital), and by his own devotion to the arts, together with that of his daughter Amalason- tha, revivified the spirit of a fast perishing craft. After the transfer by Constantino of the imperial seat to Constantinople, the arts were again successfully cultivated by the Greeks, who made free use of the architectural treasures left by the ancients. Then appeared the dome, the glory of the Byzantine school, supported by its pendentives highly ornamented with mosaic. This principal feature of the By- zantine school induced their architects to aban- don the Latin cross (which form had gradually grown out of that of the Roman basilica) in the plan of their churches, introducing instead the Grecian cross, whose branches are of equal length. The dome no longer rested on circular walls, but was borne by four arches resting on pillars placed at the four angles, in plan. Pen- dentives were introduced in order to sustain the circular dome, as otherwise the triangular space in the four corners would have been left without support, the diameter of the dome being equal to one of the sides of the square. In some cases the corner pillars were square, presenting an angle only at the corners, thereby giving an extraordinary degree of lightness to the structure. The semicircular arch of the Ro- mans was often elongated, in order to attain an equal height with different spans. The dogmas of the iconoclasts obliged the architects to seek some other means than sculpture of enriching their temples ; hence the profusion of mosaic work. Their ornaments represented foliage in bass-relief and interlaced lines. The capitals of the columns were square blocks similarly carved, tapering down at angles to join the cir- cular shaft. Under Narses and Belisarius the dome was introduced into Italy. The Byzantine style, whose chief promoters were Anthemius of Tralles and Isidorus of Miletus, also became the basis of the new Persian, Russian, and Sara- cen schools. We find its peculiarities existing during the middle ages in Greece, Italy, Sicily, Spain, Arabia, and India. Among the chief edifices of the Byzantine school are St. Mark's at Venice, San Vitale at Ravenna, and St. Sophia at Constantinople, the last being one of the most magnificent of the eastern em- pire. The Saracens and Moors introduced into Europe certain forms of architecture which, though differing in very many features from the classic styles, were still founded on the remains of the Grecian school, blended with the oriental elements of the Byzantine. The chief peculiarity of these styles was in the form given to the arch. The Saracenic arch was of greater depth than width. The Moor- ish style was distinguished by arches in the shape of a horseshoe or a crescent. The Sara- cens and Moors are, however, so completely one people, that it is with difficulty that the differences of their essential features can be discriminated. Their mural ornamentations, styled arabesque, presented more varied designs of graceful and ingenious combinations of geo- metrical and floral traceries than had before been known. The reproduction of animated forms was prohibited by the Koran. Another striking feature of this school is the peculiar way in which they ornamented their pendentives, by a series of little niches placed one above another, covering not only the surface of the in-
