Fourthly: Byzantine bases, if they have an incision between the upper roll and cavetto, are very apt to approach the form of fig. 23, in which the upper roll is cut out of the flat block, and the ledge beneath it is sloping. Compare Nos. 7, 8, 9, 21, 22, 23, 24, 25, 26. On the other hand, the later Gothic base, 11, has always its upper roll well developed, and, generally, the fillet between it and the cavetto vertical. The sloping fillet is indeed found down to late periods; and the vertical fillet, as in No. 12, in Byzantine ones; but still, when a base has such a sloping fillet and peculiarly graceful sweeping cavetto, as those of No. 10, looking as if they would run into one line with each other, it is strong presumptive evidence of its belonging to an early, rather than a late period. The base 12 is the boldest example I could find of the exceptional form in early times; but observe, in this, that the upper roll is larger than the lower. This is _never_ the case in late Gothic, where the proportion is always as in fig. 11. Observe that in Nos. 8 and 9 the upper rolls are at least as large as the lower, an important evidence of the dates of the Casa Farsetti and Fondaco de' Turchi. Lastly: Note the peculiarly steep profile of No. 22, with reference to what is said of this base in Vol. II. Appendix 9. _II. Doorways and Jambs._ The entrances to St. Mark's consist, as above mentioned, of great circular or ogee porches; underneath which the real open entrances, in which the valves of the bronze doors play, are square headed. [Illustration: Fig. I.] The mouldings of the jambs of these doors are highly curious, and the most characteristic are therefore represented in one view. The outsides of the jambs are lowest. _a_. Northern lateral door. _b_. First northern door of the façade. _c_. Second door of the façade. _d_. Fourth door of the façade. _e_. Central door of the façade. I wish the reader especially to note the arbitrary character of the curves and incisions; all evidently being drawn by hand, none being segments of circles, none like another, none influenced by any visible law. I do not give these mouldings as beautiful; they are, for the most part, very poor in effect, but they are singularly characteristic of the free work of the time.