Mullion

Rules that use the word

The width of the choir is the measure of all. Proportion every member of a vaulted choir from its clear width: the wall a fixed fraction of the width (a tenth, as the rule is usually read), and buttresses, window jambs, mullions and ribs as simple multiples or fractions of the wall.

Bar tracery: windows drawn with compasses. Instead of cutting separate openings through a plate of wall, fill the whole window arch with glass and divide it by slender stone bars (mullions below, and circles, foils and sub-arches above) set out with compasses from the centres of the window’s own arches.

Plate, geometric, curvilinear, perpendicular. Date a Gothic window by its tracery: openings pierced through a plate (twelfth century); geometric bar tracery of circles and foils (thirteenth); flowing curvilinear tracery of ogees and daggers (fourteenth); and, in England, perpendicular panel tracery with mullions running straight up into the arch (late fourteenth to sixteenth).

The curtain wall. Hang the outer wall from the edges of the floor slabs as a continuous skin of glass and metal, independent of the frame behind it, and express its grid of mullions.

Where it appears in the book

In the chapters Frame and Skin, Romanesque and Gothic, The Contemporary.

Nearby in the glossary

Mortise and tenon · Moulding · Mount · Mount Meru · Muqarnas · Mutule · Naga balustrade · Naos