The clerestory lights occupy the full width of the space between the piers of the upper flying buttresses. Finally, at the base of the roof runs an open-work parapet. As we have already observed, many of the windows were hastily rebuilt after the fire of which we have previously spoken. [Illustration: _Photo_] [_Ed. Hautecœur, Paris._ NORTH TRANSEPT FRONT.] =North and South Transept Fronts.=--These, as we have seen, are comparatively late work, but though subordinate to the great façade, they are of intricate design and great ornateness. They fail of effect, however, when they are compared with the monumental and inevitable grandeur of the west front. The south façade, of the date 1257, is undoubtedly the work of Jean de Chelles. An inscription tells us very exactly that it was begun on the second day of the Ides of February, in honour of the mother of Christ. There are writers who would have us believe that to the work of de Chelles we should apply, if not the word “debased,” at least the word “flamboyant.” For this there seems to be no good reason, unless, indeed, we are prepared to allow that systems of architectural classification are more important than the buildings which are their subject-matter. It will be at once recognised that the lateral fronts of Notre Dame--while they lack the elementary grandeur so conspicuous in the works of the pioneers of Gothic in the Ile-de-France--have nothing in common with the later Perpendicular buildings of England, wherein decoration runs riot and construction sometimes degenerates into trickery. The great feature of each of these minor fronts is a vast rose window. It is difficult to repress the feeling that these fronts have been deliberately constructed with a view to lend emphasis to these lovely circular insertions, rich as they are in appropriate tracery. Whether or not we are to limit the work of Jean de Chelles to the southern front (or the lower portion of it), or whether we are to attribute to him the opposite front and the arrangement of chapels adjacent to and east of the transepts, is a nice question. The documentary evidence, to which access is difficult, would, indeed, appear narrowly to limit the work of Jean de Chelles to that fragment with which he has been immemorially associated. But it were unwise to rely too closely on ancient documents in which definite statements of fact are not to be found. It is possible that, even if Jean de Chelles did not personally superintend the erection of the southern front, he designed the opposite front and the chapels in question. He may, indeed, have left pupils fully acquainted with his methods and nearly tied to him by bonds of sentiment, who in their own productions perpetuated, not merely the main features of the style of their master, but used exactly the same material as he employed. Once more, the sculptor is prominent; once more, the structural parts are adorned with beautiful statuary.