 The problems encountered in the structure and appearance of vaults was solved late in the Romanesque period with the introduction of pointed arched ribs which allowed the height of both diagonal and transverse ribs to be varied in proportion to each other.Pointed ribs made their first appearance in the transverse ribs of the vaults at Durham Cathedral in northern England, dating from 1128.Durham is a cathedral of massive Romanesque proportions and appearance, yet its builders introduced several structural features that were new to architectural design and were later to be hallmark features of the Gothic.