without, and you have some idea of the plan and beauty of this gem of Art. Another consideration that lends interest to SS. Sergius and Bacchus is its striking resemblance to the Church of S. Vitale at Ravenna. The latter was commenced in 526, a year earlier than the former, while Theodoric the Great ruled his Ostrogoths in the fair city beside the Adriatic. It was not completed, however, until 547, after the arms of Justinian had restored Ravenna to the Roman Empire. A comparison between the kindred buildings would be invidious. Let it suffice to say, speaking broadly, that the exterior arrangements of SS. Sergius and Bacchus are superior to those of its western companion, while the interior of S. Vitale is more beautiful than the interior of the church on the shore of the Sea of Marmora. But, leaving comparisons between two beautiful objects alone, it is pertinent to recognise the artistic influence of Constantinople over Art in the West here manifested. For, although the churches are too different for the one to have been copied from the other, they are so similar as to prove the existence of a common school of Art; a school which had its chief seat in the studios and workshops beside the Bosporus. Even some of the materials of S. Vitale were imported from the East; among them, “melon-capitals” like those which adorn the columns on the ground-floor of SS. Sergius and Bacchus. The similarity of the two churches has yet another interest. Their likeness constitutes them symbols of Justinian’s great policy--the reunion of the East and the West, a reunion maintained for some two hundred years after its consummation. Since that unity was impaired, they have stood, one beside the Adriatic, the other beside the Marmora, like hills which erewhile formed sides of the same mountain, and rose to the same peak, but which a cruel tide has torn apart and holds separate, in spite of their kinship. But, perhaps, the chief interest attaching to SS. Sergius and Bacchus is the fact that it represents a stage in the solution of the problem how to crown a square building with a dome, the characteristic mark of Byzantine architecture. To cover a round building, round from summit to base like the Pantheon, with a dome is comparatively an easy matter, for in that case two circular structures meet and fit together along the whole circuit of their circumferences. On the other hand, to set the round rim of a dome upon a square substructure seems an attempt to join figures which from the nature of things can never coalesce.