Ruskin's survey of Venetian architecture, which occupies the second and third volumes of The Stones of Venice, is divided into three periods: Byzantine, Gothic and Renaissance. These names, however, are no more than convenient labels; Venetian architecture, as Ruskin is at some pains to insist, is eclectic. Thus, the Byzantine period includes buildings that are mainly western Romanesque in style, and even those which are undeniably Byzantine (or eastern Romanesque) show the influence of Islamic architecture. In the chapter of the Nature Of Gothic, in fact, Ruskin distinguishes four periods, the second being the transitional phase referred to in what follows. The buildings of this phase are
'of a character much more distinctively Arabian; the shafts become more slender, and the arches consistently pointed instead of round . . . This style is almost exclusively secular.'
It is during this period that the distinctively Venetian ogival (or onion-shaped) arch emerges. The influence of northern Gothic architecture appears in Venetian churches in the thirteenth century and, before long, unites with the transitional style to give birth to a variant of Gothic that is uniquely Venetian.