56 THE STONES OF VENICE
the eye, another course of plain bricks is added above their points, increasing the width of the band by another two inches. There are five courses of bricks in the lower band, and it measures 1 ft. 6 in. in height: there are seven courses in the upper (of which six fall between the triangles), and it measures 1 ft. 10 in. in height, except at the extremity of the northern aisle, where for some mysterious reason the intermediate cornice is sloped upwards so as to reduce the upper triangles to the same height as those below. And here, finally, observe how determined the builder was that the one series should not be a mere imitation of the other; he could not now make them acute by additional height-so he here, and here only, narrowed their bases, and we have seven of them above, to six below.
§ 27. We come now to the most interesting portion of the whole east end, the archivolt at the end of the northern aisle.
It was above stated [§ 22], that the band of triangles was broken by two higher arches at the ends of the aisles. That, however, on the northern side of the apse does not entirely interrupt, but lifts it, and thus forms a beautiful and curious archivolt, drawn in Plate 5. The upper band of triangles cannot rise together with the lower, as it would otherwise break the cornice prepared to receive the second story; and the curious zig-zag with which its triangles die away against the sides of the arch, exactly as waves break upon the sand, is one of the most curious features in the structure.
It will be also seen that there is a new feature in the treatment of the band itself when it turns the arch. Instead of leaving the bricks projecting between the sculptured or coloured stones, reversed triangles of marble are used, inlaid to an equal depth with the others in the brick-work, but projecting beyond them so as to produce a sharp dark line of zig-zag at their junctions. Three of the supplementary stones have unhappily fallen out, so that it is now impossible to determine the full harmony of colour in which they were originally arranged. The central one,
[Version 0.04: March 2008]