terval of more than two feet between it and the top of the western arch, filled by added courses of masonry. There is another very curious evidence of this struggle of the architect with his yielding wall in the columns of the main entrance. (These notices are perhaps somewhat irrelevant to our immediate subject, but they appear to me highly interesting; and they, at all events, prove one of the points on which I would insist—how much of imperfection and variety in things professing to be symmetrical the eyes of those eager builders could endure: they looked to loveliness in detail, to nobility in the whole, never to petty measurements). Those columns of the principal entrance are among the loveliest in Italy; cylindrical, and decorated with a rich arabesque of sculptured foliage, which at the base extends nearly all round them, up to the black pilaster in which they are lightly engaged : but the shield of foliage, bounded by a severe line, narrows to their tops, where it covers their frontal segment only; thus giving, when laterally seen, a terminal line sloping boldly outwards, which, as I think, was meant to conceal the accidental leaning of the western walls, and, by its exaggerated inclination in the same direction, to throw them by comparison into a seeming vertical.
XI. There is another very curious instance of distortion above the central door of the west front. All the intervals between the seven arches are filled with black marble, each containing in its centre a white parallelogram filled with animal mosaics, and the whole surmounted by a broad white band, which, generally, does not touch the parallelogram below. But the parallelogram on the north of the central arch has been forced into an oblique position, and touches the white band; and, as if the architect was determined to show that he did not care whether it did or not, the white band suddenly gets thicker at that place, and remains so over the next two arches. And
