The cathedral of Paris was designed at a time when the architects had not obtained that confidence in their own skill which made them afterwards complete masters of the constructive difficulties of the design. As shown in the plan (Woodcut No. 620), the points of support are far more numerous and are placed nearer to one another than is usually the case; and as may be seen from the section, instead of two tall storeys, the height is divided into three, and made up, if I may so express it, of a series of cells built over and beside each, so as to obtain immense strength with a slight expenditure of materials. [Illustration: 623. Plan of Chartres Cathedral. (From Chapuy.) Scale 100 ft. to 1 in.] It must at the same time be confessed that this result was obtained with a considerable sacrifice of grandeur and simplicity of effect. Even before the building was completed, the architects seem to have become aware of these defects; and as is shown in the woodcut (No. 622), the simple undivided windows of the clerestory were cut down so as to give them the greatest possible height, and the roof of the upper gallery made flat to admit of this. Subsequently larger windows were introduced between the buttresses, with a view to obtaining fewer and larger parts, and also of course to admit of larger surfaces for painted glass. With all these improvements the cathedral has not internally the same grandeur as the other three, though externally there is a very noble simplicity of outline and appearance of solidity in the whole design. Internally it still retains, as may be seen from the plan, the hexapartite arrangement in its vaults over the central aisle, and the quadripartite in the side-aisles only. This causes the central vault to overpower those on each side, and makes not only the whole church, but all parts, look much smaller than would have been the case had the roof been cut into smaller divisions, as was always subsequently the case. [Illustration: 624. Plan of Rheims Cathedral. Scale 100 ft. to 1 in. (From Chapuy.)] [Illustration: 625. Plan of Amiens Cathedral. Scale 100 ft. to 1 in.]