In the drawing above I have imposed Shroder's plan of the setting up on the outside of the chamber, and although the alignment is nor exact because of the angle from which the picture has been taken, the relationship of key structural components to this proportion is fairly clear.
"The total inner height is twice the base and this total height is divided at Zeising's 'Golden Section' in such a way that the lesser part is below ... The peak of the lower main arch is at Zeising's section of the height of the great octagon arch which surmounts it ... Since it is the property of the pentagon that a perpendicular from the apex to the base is divided at its Golden Section by a line joining the remaining angles, the pentagon in the dome interior must be taken as the architect's symbol of the ratio, which he has twice employed."The architect was perfectly aware of what he was doing and the roof incorporates a pentacle in the insider as if to give a clue to the tranquil effect he has evoked.