Page:A History of Architecture in All Countries Vol 2.djvu/454

438 BYZANTINE ARCHITECTUEE. Part II. 876. Diagram of Vaulting. (From VioUet le Due, " Entre tieus d' Architecture.") Constructively it would probably have been easier to roof the space by an intersecting vault. Even if of 100 or 150 ft. span, it could without difficulty have been effected by the arrangement shown in the annexed diagram (Woodcut No. 876). The difference be- tween the intersect- ing vault and the dome, as applied in this instance, is per- haps the most strik- ing contrast the his- tory of architecture affords between me- chanical and orna- mental construction. Both are capable of being ornamented to ' the same extent and in the same manner; but the difference of form rendered the cir- cular dome a beautiful object in itself, wholly irrespective of orna- ment, while nothing in the architect's repertory could redeem the mechanical harshness of a single vault, when applied on the scale requisite to roof an apartment of any considerable dimensions. Altogether, the effect would have been architecturally so infinitely inferior that we cannot but feel grateful to the Byzantines that they persevered in spite of all mechanical tempta- tions till they reached the wonderful pertec- tion of the dome of Sta. Sophia. Amonsr the earliest domical churches found in the East is that of St. George at Thessa- lonica. It is also, perhaps, the finest example of its class, belonging strictly to that group which has been designated above as the East- ern Romanesque. As will be seen from the plan, it is a circular apartment, 79 ft. in diameter, sur- rounded by walls 20 ft. in thickness, into which are cut seven great niches, two appa- rently serving as entrances, opposite one of which is a bema or presbytery of considerable importance and purely Christian form. 877. Plan of St. George at Thessalonica. Scale 100 ft. to 1 in.