contained twelve bays, that of St. Albans contains thirteen and that of Norwich fourteen, while in France the nave of the Cathedral of Paris, which is one of the longest, contains but ten bays, that of Chartres contains but nine, and that of Amiens but six. As to the comparative heights, it may suffice to say that the choir of Lincoln measures, from the pavement to the crowns of the vaults, about twenty-two metres, while the nave of Amiens measures forty-two. It must be said, however, that vaults in England are sometimes a little higher than those of Lincoln choir, while in France none except those of Beauvais are higher than Amiens, though almost all are much higher than those of Lincoln.
The vaulted polygonal chapter-house is a structure peculiar to England. It is usually octagonal, as at Salisbury and York. At Lincoln the plan is decagonal. The chapter-house is vaulted on a system of ribs which spring from a clustered central shaft, and from single shafts situated in the angles of the enclosing walls. What may be approximately described as a pointed annular vault, interpenetrated by pointed cells, is thus sustained. The openings in these structures have often a more Gothic character than those of the church edifice itself. At Salisbury, for instance, the whole space beneath the vault cell on each side of the polygon is taken up by the opening. The internal effect of these structures is very pleasing, but they present no principles that are materially different from those which we have already considered. The same want of constructive logic that we have noticed in the pointed architecture of England generally is still often apparent. For instance, at Salisbury the central column consists of a main body and eight attached monolithic shafts, with an octagonal abacus to its grouped capitals. Upon this abacus sixteen vaulting ribs—namely, the transverse ribs and the half-ribs which reach to the intersection of the groins of the intersecting cells—converge. The plan of the rib group at the impost is thus a sixteen-sided polygon, which does not adjust itself well to the octagonal abacus of the column; and the consequence is that the ribs fall alternately upon a sustaining shaft and upon one side of the abacus over an intercolumniation. This structural defect is just the reverse of that which was noticed above in relation to the pier (A, Fig. 77) at the
