It is probably to St. Hugh of Lincoln that we owe the first perfect vault in England. Coming from Burgundy he must have been familiar with the great vaults which had been constructed in his country long before the year 1200, when he encouraged his new followers to undertake one not necessarily in the Burgundian style, but in that form with which they were conversant from their practice in erecting smaller side-vaults. He built and roofed the choir of Lincoln, immediately after which (1209-1235) the nave (Woodcut No. 811) was undertaken by Hugh of Wells, and its roof may be taken as a type of the first perfected form of English vaulting. It is very simple and beautiful; but it cannot be denied—and this is felt still more at Exeter—that the great inverted pyramidal blocks of the roof are too heavy for the light pier and pierced walls which support them. Another defect is, that the lines of the clerestory windows do not accord with the lines of the “severeys” of the vault. This defect was remedied at Lichfield, but nowhere else, until the invention of the four-centred arch and of fan-tracery. At Lichfield (Woodcut No. 812) the triangular form of the clerestory windows afforded a perfect solution of the difficulty, and gave a stability and propriety to the whole arrangement that never was surpassed, and never might have been relinquished had not their fatal fondness for painted glass forced the architects in this, as in other instances, to forego constructive propriety for indulgence in that fascinating mode of decoration. [Illustration: 811. Nave of Lincoln Cathedral. (Cath. Hb.)] Beautiful as these simple early roofs were felt to be, the great mass of the “severeys,” or inverted pyramids, formed a very obvious defect. It was, however, easily remedied when once perceived. The earliest example of its successful removal is probably in the roof of the choir at Gloucester (1337-1377) (Woodcut No. 813). In this instance the roof is almost a tunnel-vault with the window spaces cutting into it, so as to leave nearly one-third of the space unbroken; and, as the whole is covered with rich and appropriate tracery, the effect is highly pleasing. The same principle was afterwards carried to its utmost perfection in the roof of St. George’s Chapel at Windsor. In that case a flat band was introduced as a separate constructive compartment in the centre, supported by the severeys, and as the roof is ornamented with ribbings of the most exquisite design, it forms perhaps the most beautiful vault ever designed by a Gothic architect. [Illustration: 812. Nave of Lichfield Cathedral. (Cath. Hb.)]