_Shafts and Bases._--The usual theory that the Byzantines wrought but few new marble shafts does not bear scrutiny. Byzantine shafts have neckings of very slight projection, thus obviating the waste of labour and material of Roman work.[360] The shafts of the baptistery loggia at S. Sophia, figured by Salzenberg, furnish good examples; sometimes the necking, as to the square marble pillars, is a simple broad fillet of about a quarter of an inch projection. The hundred round shafts of S. Sophia exhibit a remarkable and beautiful structural expedient by which the necking is entirely suppressed, and bronze annulets surround the shaft under the capital and above the base; which prevent the shafts from sliding or splitting, and retain the lead beds from being forced out by the weight (see Choisy, p. 15). Large monolithic shafts were the more apt to split, as they had to be set up contrary to the direction of the quarry strata. [Illustration: FIG. 59.--Marble Pedestals and Skirting Slabs.] Fig. 58 represents these bronze zones in association with the great capitals and bases. The pedestals of the exedra columns A _a_, next figure, are worked together with the bases in one stone. In these profiles we again see how little the mouldings disturb the original form. [Illustration: FIG. 60.--Cornice Profiles.] _Responds._--A very remarkable feature in the interior, is the way in which the colour of the marble columns of the arcade is reflected as it were on the responds, where the arches fall on the great square piers. A strip of porphyry or verde antique, the width and height of the free shafts, is inlaid into the marble casing of the piers absolutely flush, the edge being only defined by a line of the notched fillet. A flat sculptured slab at the top echoes the capital, and a base slab of mouldings worked in a vertical plane ranges with the bases of the columns. Salzenberg’s plate does not render this feature properly, the “capital” is flat and has straight sides and instead of the “base” he shows a portion of the wall skirting. Fig. 59 shows this base in elevation (B), and section (C), ranging with the pedestals of the exedra, Columns (A). The way in which the sculptured and inlaid spandrils of the arcades stop against the plain veneering of the great piers is also most noteworthy. _Cornices and Skirtings._--We give here (Fig. 59, D and E) two profiles of the skirtings where the principle of working out of thin veneering-slabs is applied to moulded work. The parapet slabs of first floor are worked in a very similar way; Salzenberg shows design of front, and they bear flat lozenges between two crosses at the back. See Fig. 61.