On the exterior the clere-storey has two adjoining pointed windows and a cornice with brackets, while chapels fill up the spaces between the buttresses of the side-aisles. The buttresses rise above the roofs of the side-aisles to half the height of the nave, and arches spring from them to the wall of the latter, to conduct the thrust of the vaults to the outside, and thus to relieve the columns of a portion of their load as well as of the lateral thrust of the groining of the nave. These buttresses and flying buttresses not only introduce a new method of diversifying the exterior and at the same time express the arrangement of the interior vaulting, but also so far influence the interior itself that the arches no longer need massive pillars, the place of which can be taken by light columns, which are secured against the thrust of the vaults of the side-aisles by the weight resting upon them.
The Church of Noire Dame at Chalons, completed in 1183, makes a brilliant display of a choir with surrounding aisle and a crown of semi circular attached chapels (forming what is called a chezr6. Round pil lars from whose capitals three shafts rise aloft support the arches of the choir, while the chapels are separated from the aisle by slender columns. Above the aisle of the apse is a semicircnlai gallery. The windows of the aisle, as well as those of the principal apse, are narrow and high; they are enclosed in pointed arches and placed in groups of three, so that they fill almost the whole of the space between the piers. By this arrangement the height of the interior is greatly increased. The entire constructive scaffolding is reduced to the buttresses, which project between the chapels, and from each of which a massive flying-buttress is thrown to the walls of the gallery, while abyvc this a second greater flying-buttress springs to the walls of the clere-storey. The pointed arch predominates through out. The wealth of columns gives to the interior a most poetical charm: the range which stands in front of the crown of chapels produces 'won derful perspectives, and the effect is increased by the architecture of the gallery-front and by the columned gallery called the triforium, which stands above the gallery and adorns the part of the wall against which its roof abuts.
Similar is the arrangement of the choir of St. Remy at Rheims, in which, however, the central chapel has several bays of vaulting and pro jects from the main building, which consists of a three-aisled nave with a three-aisled transept, while the choir has five aisles as far as the chevet.
At Blois is the small Church of St. Latimer, begun before 1138 and fin ished in 121o. This exhibits about the same stage of development. The nave has three aisles; the transept, one. The choir, only two bays in length, has five aisles, the two outermost of which end in semicircular apses, while the inner ones meet by running around the principal apse. Three chapels radiate from the aisles of the apse.
Noyon church in which architectural progress is dis played most conspicuously is the Cathedral of Noyon, commenced in 15o, though the choir was not completed until the close of the century and the nave is of the thirteenth century. The plan (pi. 29, fig. 6) shows that here, as in earlier examples, the side-aisles of the choir ran around the apse, which, instead of ending in a naked wall, is reduced to piers connected by arches. The upper part of the wall is adorned with a gal lery, which runs completely around it, but each internal pier of the apse corresponds to a second massive outer one, and between these, as in the French churches of an earlier period, are small apsidal chapels. The pro jecting arms of the long transepts end also in an apse.
The Church of .Varc Dame at Paris T) was the third structure upon the site, and was commenced by Bishop Maurice de Sully (116o 1196); the first stone was laid in 1163. At his death he left a sum of five thousand livres for the lead roof of the choir, which was probably at that time nearly ready to be roofed. The nave was completed in the first quarter of the thirteenth century. (The old Church of St. Stephen on the site of Notre Dame was demolished in 1218.) In this edifice of the close of the twelfth century we find the most magnificent arrangement of the choir. It has five aisles, the centre one lofty, the inner side-aisles with a gallery above. The pillars and arches of the choir have the form of massive round columns. The gallery opens toward the middle aisle by an arcade with pointed arches, under which two smaller pointed arches are placed on colonnettes. The profiles of the smaller arches have broad rebates, the angles of which have roll-mould ings, and a roll-moulding also runs round the main arch. The windows of the middle aisle were altered at a later date, and were doubtless similar to those which the outside of the entire nave still exhibits—that is, simple round or pointed openings with a colonnette on each side. From the capitals of the pillars three shafts rise aloft" and ciit through the cor nice, to carry the springing of the vaulting.