§ II. Now, the main things to be expressed in a base are its levelness and evenness. We cannot do better than construct the several members of the base, as developed in Fig. II., p. 55, each of a different colored marble, so as to produce marked level bars of color all along the foundation. This is exquisitely done in all the Italian elaborate wall bases; that of St. Anastasia at Verona is one of the most perfect existing, for play of color; that of Giotto's campanile is on the whole the most beautifully finished. Then, on the vertical portions, _a_, _b_, _c_, we may put what patterns in mosaic we please, so that they be not too rich; but if we choose rather to have sculpture (or _must_ have it for want of stones to inlay), then observe that all sculpture on bases must be in panels, or it will soon be worn away, and that a plain panelling is often good without any other ornament. The member _b_, which in St. Mark's is subordinate, and _c_, which is expanded into a seat, are both of them decorated with simple but exquisitely-finished panelling, in red and white or green and white marble; and the member _e_ is in bases of this kind very valuable, as an expression of a firm beginning of the substance of the wall itself. This member has been of no service to us hitherto, and was unnoticed in the chapters on construction; but it was expressed in the figure of the wall base, on account of its great value when the foundation is of stone and the wall of brick (coated or not). In such cases it is always better to add the course _e_, above the slope of the base, than abruptly to begin the common masonry of the wall. § III. It is, however, with the member _d_, or Xb, that we are most seriously concerned; for this being the essential feature of all bases, and the true preparation for the wall or shaft, it is most necessary that here, if anywhere, we should have full expression of levelness and precision; and farther, that, if possible, the eye should not be suffered to rest on the points of junction of the stones, which would give an effect of instability. Both these objects are accomplished by attracting the eye to two rolls, separated by a deep hollow, in the member _d_ itself. The bold projections of their mouldings entirely prevent the attention from being drawn to the joints of the masonry, and besides form a simple but beautifully connected group of bars of shadow, which express, in their perfect parallelism, the absolute levelness of the foundation.