And you will be surprised to find, when you try the experiment, how much the eye must instinctively judge in this manner. Take the front of San Zenone, for instance, Plate I. You will find it impossible, without a lens, to distinguish in the bronze gates, and in great part of the wall, anything that their bosses represent. You cannot tell whether the sculpture is of men, animals, or trees; only you feel it to be composed of pleasant projecting masses; you acknowledge that both gates and wall are, somehow, delightfully roughened; and only afterwards, by slow degrees, can you make out what this roughness means; nay, though here (Plate III.) I magnify[10] one of the bronze plates of the gate to a scale, which gives you the same advantage as if you saw it quite close, in the reality,--you may still be obliged to me for the information that _this_ boss represents the Madonna asleep in her little bed; and this smaller boss, the Infant Christ in His; and this at the top, a cloud with an angel coming out of it; and these jagged bosses, two of the Three Kings, with their crowns on, looking up to the star, (which is intelligible enough, I admit); but what this straggling, three-legged boss beneath signifies, I suppose neither you nor I can tell, unless it be the shepherd's dog, who has come suddenly upon the Kings with their crowns on, and is greatly startled at them. 23. Farther, and much more definitely, the pleasantness of the surface decoration is independent of structure; that is to say, of any architectural requirement of stability. The greater part of the sculpture here is exclusively ornamentation of a flat wall, or of door-paneling; only a small portion of the church front is thus treated, and the sculpture has no more to do with the form of the building than a piece of lace veil would have, suspended beside its gates on a festal day: the proportions of shaft and arch might be altered in a hundred different ways without diminishing their stability; and the pillars would stand more safely on the ground than on the backs of these carved animals.