The Romanesque chancel has entirely disappeared, and there does not exist any trace of its original form. It was probably, as we have seen in the historical notice, nearly like that of the church of Gerisy-la-Forêt, the apse of which still exists.
The present chancel was built from 1450 to 1521 on the enlarged site of the Romanesque chancel, which fell down in 1421. Although it was constructed with very strong granite, like the other buildings of the Mount, it is very carefully formed and is a very good specimen of the edifices built during the last times of the pointed architecture. It seems to be evident that they wished in the XV century, to rebuild entirely the church in the same style as the new chancel; this plan was commenced to be put in execution, and the intentions of the builders of 1450 are easy to be seen. This project is visible in the whole of the constructions and especially in the angles formed by the chancel and the transepts.
In these places, the flying buttresses really sustaining the thrust of the vaults of the chancel cross each other with those of the projected transepts; these last flying buttresses, without reason and without object just now in anticipation of the further rebuilding of the transept according to the new plan.
We can judge of these arrangements by going round the chancel on the terraces of the apses of the chapels which we reach by the staircase built in the solid south buttress and the entrance of which is in the third south chapel.
The arrangement of this triforium is very ingenious; the exterior gallery goes round the supports on which it is constructed like corbels, in order to give them all the necessary strength, by forming on the base of the large windows and of the buttresses an architectural combination of a very nice effect.
The chancel is composed of a central nave, ended on the east by an apse with chamfers surrounded by an aisle around which extend and radiate lateral chapels with apses. The chapels of the north side are narrower than those of the south and have a different form. This difference rendered necessary by the architecture can be explained by the proximity of the buildings of the Merveille which would have been spoilt by the north collateral if this part of the church had been absolutely like the south one.
The construction of the chancel is very remarkable; the conception is grand and the execution a real masterpiece of that kind of architecture. The exactness and the regularity of the details show that perfect science and knowledge directed the geometrical operations which were necessary when its foundations were raised to the level of the soil. The perfection of the cut of the granite, the clearness of the most complex moldings, and the perfect sculptures show what art and what care was employed in the construction of these works.
After seeing the nave and the chancel, the visitor will be able to make an interesting ascent. By taking the staircase which we have already mentioned, in the third radiating chapel, he will reach the galleries of the triforium and, by ascending again the flight of steps built on the raking part of a flying buttress and called the jagged staircase ending at the upper balustrade of the timber-roof, he will have before his eyes an immense panorama. He must afterward go down by the same way to the foot of the staircase whence he ascended to the third chapel and which has its starting point in the lower church.
LOWER CHURCH CALLED CRYPT OF THE LARGE PILLARS
The difference between the level of the higher church and the exterior soil has necessitated the construction of considerable basements; they formed the Lower churchy called crypt of the large pillars which reproduces with great simplicity the arrangements of the chancel, except the lateral chapels of the first transverse compartment, which the rock prevented being made and those of the second transverse compartment in the place of which have been put cisterns made at the time of the constructions in the depth of the substructures. The pillars, round, thick, and short, without capitals, receive by penetrations wath corbels the coussinets of the vault and serve as the solid base for the piers of the chancel of the higher church.
A fortified bridge, formerly having battlements and which has still its machicolations, crosses the churchyard and makes the lower church communicate with the abbatial dwelling on the south and the Merveille on the north. After visiting the lower church, the visitor ought to go out on the north by the lateral door opening on a narrow yard at the end of which is, towards the east, a terrace whence he will admire the apse of the church and the south front of the Merveille; afterward, he must ascend the staircase winding round that terrace and which ends, on the level of the Guards’hall, in the court of the Merveille.