bk. yul ch. l historical notice. 295 master the peculiarities of their art, and we can with certainty pronounce when any particular race rose to power, how long its prevalence lasted, and when it was obliterated or fused with some other form. There is no great difficulty in distinguishing between the Byzantine and the other two styles, though it is only after reading the next book of this work that its peculiarities can be fully explained. Meanwhile, liowever, there is no difficulty in distinguishing between the Gothic and Byzantine form of dome. The latter is almost always rounded externally, the former always straight-lined. Again : the Byzantine architects never used intei'secting vaults for their naves. If forced to use a pointed arch, they did so unwillingly, and it never fitted kindly to their favorite circular forms; the style of their ornamentation was, throughout peculiar, and differed in many essential respects from the other two styles. It is less easy always to discriminate between the Gothic and Romanesque in Italy. We frequently find churches of the two styles built side by side in the same age, both using round arches, and with details not differing essentially from one another. There is one test, however, which is probably in all cases sufficient. Every Gothic church had, or was intended to have, a vault over its central aisle. No Romanesque church ever attempted it. The importance of the distinction is apparent throughout. The Gothic churches have clustered piers, tall vaulting shafts, external and internal buttresses, and are prepared throughout for this necessity of Gothic art. The Romanesque churches, on the contrary, have only a range of columns, generally of a pseudo-Corinthian order, between the central and side aisles ; internally no vaulting-shafts, and externally only pilasters. Had these architects been competent, as the English were, to invent an ornamental wooden roof, they Avould perhaps have acted wisely ; but though they made several attempts, especially at Verona, they failed signally to devise any mode either of hiding the mere mechanical structure of their roofs or of rendering them ornamental. As before pointed out,^ vaulting was the real formative idea of the Gothic style, and it continued to be its most marked characteristic during the continuance of the style, not only in Italy, but throughout all Europe. As it is impossible to treat of these various styles in one sequence, various modes of precedence might be adopted, for each of which good reasons could be given : but the following will probably be found most consonant with the arrangement elsewhere adopted in this work : — First to treat of the Gothic styles of Northern Italy, because they Vol. i. p. 448 et seq.
