That this space is not available to the interior of S. Sophia has caused Choisy to criticise the design in this respect as “a solution undecided, _moyen terme_, _fâcheux_; the large arches by a departure from ordinary rule being thrown on the outside so that the space covered by them was lost. S. Sophia Salonica redressed this error.” We wonder that Choisy’s views as to the original base of the dome did not cause him to take the further step we have here suggested. The present form, in which the lateral arches support the square base of the dome, is at least a possible one; but that the arches when they carried nothing and thus were actually vaults (as before shown by Choisy) were not filled with a screen but were mere arches twelve feet on soffite, lying against the sides of the building seems inconceivable. In our Figure 34 we have amended Choisy’s view in this respect. Looking on these lateral arches as vaults we have filled them with a window like the western vault, and the harmony which results between the sides and the west end amply verifies our conclusions. One point further. The upper surface of the base of the dome on the west side should not be wholly level as shown in Fig. 34, the central third _curves up_ following the line of the top of semidome. In other words, the great arch of the interior pushes itself up through the base of the dome, and this treatment thus recurred at various heights--over large windows of aisles, over western and lateral lunettes, as we have shown, and over the semidome.