X. In the Lombard Romanesque, the two principles are more fused into each other, as most characteristically in the Cathedral of Pisa: length of proportion, exhibited by an arcade of twenty-one arches above, and fifteen below, at the side of the nave; bold square proportion in the front; that front divided into arcades, placed one above the other, the lowest with its pillars engaged, of seven arches, the four uppermost thrown out boldly from the receding wall, and casting deep shadows; the first, above the basement, of nineteen arches; the second of twenty-one; the third and fourth of eight each; sixty-three arches in all; all _circular_ headed, all with cylindrical shafts, and the lowest with _square_ panellings, set diagonally under their semicircles, an universal ornament in this style (Plate XII., fig. 7); the apse, a semicircle, with a semi-dome for its roof, and three ranges of circular arches for its exterior ornament; in the interior of the nave, a range of circular arches below a circular-arched triforium, and a vast flat _surface_, observe, of wall decorated with striped marble above; the whole arrangement (not a peculiar one, but characteristic of every church of the period; and, to my feeling, the most majestic; not perhaps the fairest, but the mightiest type of form which the mind of man has ever conceived) based exclusively on associations of the circle and the square. I am now, however, trenching upon ground which I desire to reserve for more careful examination, in connection with other æsthetic questions: but I believe the examples I have given will justify my vindication of the square form from the reprobation which has been lightly thrown upon it; nor might this be done for it only as a ruling outline, but as occurring constantly in the best mosaics, and in a thousand forms of minor decoration, which I cannot now examine; my chief assertion of its majesty being always as it is an exponent of space and surface, and therefore to be chosen, either to rule in their outlines, or to adorn by masses of light and shade those portions of buildings in which surface is to be rendered precious or honorable. XI. Thus far, then, of general forms, and of the modes in which the scale of architecture is best to be exhibited. Let us next consider the manifestations of power which belong to its details and lesser divisions.