The portico of the Pantheon he thought perfect in plan, and magnificent in effect. He admired its great depth, the increase of this in the centre, and above all the disposition of the inner columns, which gave apparent stability and variety of effect, without confusing the eye or obstructing the approach. He never could endure a portico which was shallow, or which had no inner columns, or which had the wall, the background of the columns, broken up by windows. But the junction to the circular building appeared to him unhappy. In fact he objected _in toto_ to the treatment of a portico as a mere porch, thinking that in all cases the portico should be a continuation of the main building.[23] The interior he used to quote as the finest example in the world of the grandeur of a dome, when sufficiently large, and sufficiently near the eye to be comprehended in one glance. Domes like that of St. Peter’s, which could only be seen by a painful throwing back of the neck, seemed to him wrong in principle. For at all times he held, that interiors should be so contrived that a spectator on entering should see enough of the design to enable him to comprehend the whole, and that, when this was not the case, there was a distraction of thought, fatal to any striking effect. The exterior of the cathedral at Florence seemed to him grand only in size, “unworthy to be compared with our best Gothic cathedrals;” and the arrangement of black and white marbles such as to destroy both massiveness of general effect and beauty of form in its various parts. The dome, as the largest in the world, and the first constructed after St. Sophia, called for attentive study, especially in construction; but it convinced him that “polygonal domes should be avoided, especially when ribbed and of few sides. If, on looking directly at the dome, you do not see exactly an equal portion of the two remote sides, the perspective gives an untrue figure; and when the ribs are prominent and far removed from each other, this effect is increased.” The general architecture seemed to him a vicious mixture of Roman and Gothic, though details, especially the beautiful external cornice running round the building, were worthy of study and admiration. On entering he acknowledged that the effect was simple and imposing, in apparent size grander than St. Peter’s, and even approaching the sublime. But the details appeared to him unworthy of special notice.