Apse

In an astronomical orbit, the apsis identifies the twin centers of the parabola that describes its curve.

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Full descriptions of the elements of a Gothic floorplan are found at the entry Cathedral diagram. . The apse is coloured gray (ambulatory and radiating chapels) and green (sanctuary).]] In Romanesque and Gothic Christian abbey, cathedral and church architecture, the apse (Latin absis "arch, vault") is the semi-circular or polygonal section of the sanctuary at the liturgical east end beyond the altar (plan, right). The semicircular projection (which may be polygonal on the exterior, or reveal the radiating projections of chapels) may be roofed with a half-dome or with radiating vaulting. A simple apse may be merely embedded within the wall of the east end. Eastern orthodox churches may have a triple apse, which is usually a mark of Byzantine influence when it is seen in Western churches. Smaller subsidiary apses may be found around the choir or even at the ends of transepts.

Compare the exedra of Classical architecture, which may be considered apsidal, a feature of the secular Roman basilica, which provided some prototypes for Early Christian churches. The apse in the Roman basilica was often raised (as the sanctuary generally still is) as a hieratic feature that set apart the magistrates who deliberated within it.

An exedra or apse may be reduced in scale to form a niche within the thickness of walling; a niche does not reveal its presense by projecting on the exterior.

The interior of the apse is traditionally a focus of iconography, bearing the richest concentration of mosaics, or painting and sculpture, towards which all other decoration may tend.

further text to come

Various architectural features that are part of the apse are drawn together here:

Table of contents

1 Chancel
2 Presbytery
3 Choir
4 Chevet
5 Ambulatory

In the beginning of the 13th century in France, the apses were built as radiating chapels outside the choir aisle, henceforth known as the chevet (French, "headpiece"). Famous northern French examples of chevets are in the Gothic cathedrals of Amiens, Beauvais and Reims. Such radiating chapels are found in England in Norwich and Canterbury cathedrals, but the fully-developed feature is essentially French, though the Francophil connoisseur Henry III introduced it into Westminster Abbey.

Ambulatory

text to come