The Geometry of the New Building Plan c.1500 related to the Geometry of the Twelfth Century Sanctuary.

Figs. 233, 234.


The 87 foot circle within a square and circumscribing an octagon, as found throughout the Norman plan of c.1110, is continued as the geometry of Wastell’s retrochoir c.1500.  Not only was the architect of the new building fully aware of the geometry of his predecessor by four centuries, but he was also clearly aware of the exact geometry of the Sanctuary area, for otherwise he could not possibly have known where to set the centre of his basic 87 foot circle that he has in fact set exactly on the large Sanctuary circle indicated by the circular motif in the adjacent triforium.  It was for such a purpose that the circular motif had been set in place in conjunction with its lozenge quatrefoil.

It will be seen that the lines of the outer square of Wastell’s geometry lie exactly centrally through his narrower walls and still exactly in conformity with the surface of his window glass, while in the twelfth century sanctuary area, as in the rest of the Norman choir and nave, the geometry and the glass lie at two thirds the width of the wider wall.

I am unable to discover any meaningful or hidden geometry in the design of the fan-vaulting of the retrochoir. Leedy (1980) seems concerned to relate fan-vaulting design to what appears to be a form of sun-worship, or perhaps sun-symbolism, involving the deification of royalty:

The 4th Pageant ‘The Sphere of the Sun’ for the reception of Katherine of Aragon in 1501 was designed as a ‘celestial palace’ and displayed an image of Prince Arthur, heir apparent to the throne of England and Katherine’s spouse, seated upon a golden throne and situated in the middle of a wheel amidst a revolving cosmos.  “Beneath his chair there were IIII great stars, like IIII wheels runnyng very swyfte”.  Above his head there was a representation of the Father of Heaven.  A Host of angels were grouped around the Father of Heaven.

Sydney Angelo. In Spectacle, Pageantry and Early Tudor Policy proves that the pageant shamelessly identifies Prince Arthur both with Christ the Redeemer and with Christ the Sun of Justice.Henry VII in the 5th pageant is identified with God the Father.

(Leedy 1980, 19 & 50)


The relevance of the sanctuary tympani motifs to the plan geometry of the area is indicated by the following considerations:

a.        There are no other motifs of any kind in the twelfth century church, except for the single motif at the extreme west end of the nave.  Nor are there any on the exterior of the Anglo-Norman building

b.         Their designs appear to be unique in English architecture.  One cannot be totally assertive on this opinion, but others are welcome to search as assiduously as they may feel inclined.

c.        The Ö2 ratio between the centres of the lozenge motif is proof of its geometry.  The 24 inch (61cm) diameter of the single circle exactly circumscribes the octagon of the lozenge motif.  Why should they be so exactly geometrically related if they are not to be combined? 

d.        When their combined geometry is projected exactly in line with the single circle at the scale of the window glass dimension it exactly conforms to the dimensions of the semi-circular apse in three respects: its inner wall, its outer wall, and its line of glass. It also relates exactly to the geometry of the choir, its diameter being identical with the eastern side of the choir’s contiguous square.

e.         The circular motif is set exactly in line with the altar steps.  As Mâle insists,    “Position, grouping, symmetry and number are of extraordinary importance...After orientation it was relative position ...” (Mâle 1961, 5, 6).  It is inconceivable that overlooking the most sacred place in one of the most prestigious and wealthy abbeys in England, at a time c.1110, when relative position was of the highest importance theologically, an experimental bit of fun should deliberately be set in place.  The circular motif was there with a most serious purpose.  Anything else would have been sacrilege. This is not, after all a Gothic building but Romanesque, and the architect undoubtedly a prelate.

f.          The forms presented are of immediate relevance to the High altar of Christ: the circle, the nimbus, as the symbol of sanctity, and the lozenge, as I term it, in fact a cross, its geometry derived from the octagon star or octagram: then the two combined, and as Mâle explains, “the nimbus impressed with a cross is the sign of divinity which he [the artist] will always use in portraying any of the three persons of the Trinity”  (Mâle 1961, 2).  And then the octagon star, that links the circle to the cross-lozenge, is the sign for the resurrected Christ and the New Life, which would seem to be of close relevance to the sacrament of the Eucharist.

g.        When Wastell designed his retrochoir four centuries later, he centred his geometry exactly on the circumference of the main 87foot circle of the twelfth century    sanctuary, a point that was not indicated in the fabric. It was indicated only in the rare geometry of the tympani motifs. 

The architect of c.1110 would certainly not have known that four centuries later another architect would build a square retrochoir around his apse, but he would have known that it was always possible that changes would be made.  He would have encountered many examples, probably being personally involved in the alterations and additions.  Recording his geometry was a professional duty, being part of his job, for any future alien geometry would destroy the church’s sanctity.  Similarly, it was an essential element of the later ‘Wastell’s’ professional duty to decipher the earlier geometry and design his work to conform with it.