Construction Design Mathematics: the reticulated Curvilinear church window

This lesson develops the theme of the ogee or s-shaped arch (see relevant lesson plan).

In the church window at Finedon, the apex comprises a vesica atop two vesicas that are curved at top and bottom into ogees, all in a net-like arrangement.

The apex is set above three lights with ogee arches. This type of tracery is termed reticulated Curvilinear.

School Curriculum: This is the first of four studies of different types of Decorative window. Each has a design that is an arrangement of circles or arcs with the same radii, within a defined perimeter, with or without overlaps. An analysis of the windows at Finedon reveals that the architect simply stacked a series of congruent windows and equilateral triangles.

The windows studied are within: the Church of St Mary the Virgin in Finedon: the only window with overlaps;

St Thomas of Canterbury, Northaw (available on another page);

Altrincham Baptist Church (ditto);

and Lincoln Cathedral (ditto).

This series of lessons is well suited to project work at IB / GCSE level.

However it arose, the ogee arch rapidly led to the development of many different tracery designs. Whereas earlier windows had a static non-directional element, now the ogee enable both mullions and tracery to intersect, curve and flow from one shape to another with an arabesque character that became known as Curvilinear tracery.