The English architects never attempted such vaults as those of Toulouse and Alby, 63 and 58 ft. respectively, still less such as that of Gerona in Spain, which is 72 ft. clear width. With our present mechanical knowledge, we could probably construct wider vaults still. Even the Mediæval architects in England might have done more in this direction than they actually accomplished, had they tried. On the whole, however, it seems that they exercised a wise discretion in limiting themselves to moderate dimensions. More poetry of design and greater apparent size is attainable by the introduction of pillars on the floor, and with far less mechanical effort. Unless everything is increased in even a greater ratio, the dwarfing effect of a great vault never fails to make itself painfully apparent. We may regret that they did not vary their vaults by such an expedient as the lantern at Ely, but hardly that they confined them to the dimensions they generally adopted. PIER ARCHES. Although the principles adopted by the English architects did not materially differ from those of their Continental confrères with regard to the arrangement of pier arches and the proportions of triforia and clerestories, still their practice was generally so sound and the results so satisfactory, that this seems the best place to point out what the Mediæval architects aimed at in the arrangement of their wall surfaces. [Illustration: 820. Transformation of the Nave, Winchester Cathedral. (Cath. Hb.)] [Illustration: 821. Choir of Ely Cathedral. (Cath. Hb.)]