Page:Character of Renaissance Architecture.djvu/72

 which he had to fit his work prevented such a disposition of the columns, and such general proportions as this model exhibits. He was obliged to make the lateral intercolumniations much wider than the central one, and to make the whole rectangle of the composition more oblong than that of the ancient monument; but in most other points he has followed the arch of Septimius Severus closely. As in the Roman design the entablature crowns the wall instead of the order, so that ressauts have to be formed to cover the columns. The insertion of the angle pilaster is a departure from the Roman scheme, and the placing of the stumpy pilaster of the attic over the great pilaster, instead of on the column, is another point of difference. But the general scheme of the ground story and attic will be seen to resemble that of the Roman design about as closely as the mediæval edifice on which it is ingrafted would allow. In San Francesco at Rimini the architect had a freer hand, and the order is treated in closer conformity with the ancient model as to the spacing of the columns and other details. The angles are treated precisely as they are in the arch of Septimius Severus, the pilasters being omitted, and the entablature at each end extending beyond the ressaut. The attic is omitted here, and the unfinished upper part of the façade is necessarily of different design.

In St. Andrea at Mantua the use of pilasters instead of columns, and the absence of ressauts in the great order, as well as the substitution of a pediment for the attic, make a great difference in the general character of the design; and yet the triumphal arch idea is even more strongly marked in this case, because it is not confined to the mere façade but extends to the form of the whole porch. The great barrel-vaulted recess is an exact reproduction of the central passageway of the Roman arch, and so are the lesser arches which open out of this recess on either side.

The triumphal arch idea applied to church fronts appears to be peculiar to Alberti. Most other architects among his contemporaries and immediate successors limit themselves to an application of the orders variously proportioned and disposed. In some cases the mediseval scheme of buttresses dividing the front into bays is retained, and this scheme is enriched with pilasters, or columns, and mouldings of classic profiling, as in the façade of the Duomo of Pienza by the Florentine