Eyes open wide to heaven

In 1979, Painton Cowen published Rose Windows . In this lavishly presented new volume, he has produced a second splendid overview of the origins, evolution and meaning of this extraordinary genre of window. It might be cruel to call The Rose Window: Splendour and Symbol a coffee-table book, but in the best sense that is what it is. The generous format requires one to find leisure to reflect on the exemplary photographs, while the text has just the right level of insight and information to draw one into the subtle shifts of architectural history that shaped the development of the rose window from its beginnings in the 6th-century Syrian oculus to Antonio Gaudí's recently glazed Sagrada Familia Cathedral in Barcelona.

The book's opulence is so irresistible that it took me several attempts before my eyes could settle on the words. The preface speaks of the change the author has undergone since first tackling his subject: "I am much happier now to let each window speak for itself." This approach gives readers room to discover their own preferences among the riot of amazing designs. Cowen is right to assert that rose windows still "seem to speak directly to the individual, catching us unawares and slipping past the inquiring intellect by the impact solely of their form, light and colour".

After defining a rose window's two component parts, namely the stone tracery within a monumental masonry circle and the glass, the introduction launches straight into the Gothic period to lay open the mystical potential of the windows. The anagogical effect is the transportation of the individual from a lower to a higher plane of consciousness. Cowen suggests that the conjunction of light as a transformative agent with the circle as an image of the divine and the mesmerising wheeling of the tracery patterns must have exerted a magical potency on the medieval mind. By the end of his book I, too, was fully converted to this view.

Four chapters follow that trace the chronological development of the rose window through the major periods of change, with divergent national interpretations. Although these are mainly historical surveys, Cowen includes in each a section discussing the spirit of a stylistic epoch. He writes lucidly and concisely here, amply illustrated with references.

As the Roman oculus and Syrian plate tracery transennas meet in the Visigothic church of San Miguel de Lilo (near Oviedo in northern Spain), around 848 the first rose window emerges. The beautiful Cistercian windows give way to wheel roses with central hubs supported by pillar-like spokes complete with capitals. By the 13th century, Louis IX's innovative Rayonnant style is particularly arresting in its profligate variety and invention of permutations. But by the time we get to the high point of febrile ecstasy in the Curvilinear and Flamboyant style, Cowen seems to be warning us that the form is about to supplant the very purpose of the window and give way to mere decorative schemas. However, in Lincoln Cathedral's Dean's Eye and Bishop's Eye, we have two sublime examples of the marriage of stone and glass, line and colour. But after the 16th century the form becomes empty and falls out of fashion until the Gothic revival under architects such as Pugin and Viollet-le-Duc. Examples from the 20th century are thin on the ground, but a gem such as Matisse's window for the Union Church in Pocantico Hills, New York (1954), is a revelation and it makes me wonder whether there might not be a smaller compendium worth compiling of contemporary rose windows.

An outstanding strength of the book is the multiplicity of visual and textual examples. A prototype is no sooner cited than the following pages display 20 variants. Thus after absorbing the written text you begin reading the visual imagery. With up to six images on a spread, visual comparison is easy, but sometimes this frustratingly crops out any architectural context of the window, leaving one wondering what scale, height or relationship it has to its building. All examples are meticulously referenced at the back in a gazetteer and located on a labelled map of Europe, making it possible to daydream routes between chosen sites.

The final chapters are an interesting mixture of the thematic subjects of the glass and the techniques involved in the engineering, geometry and conservation of stone tracery. Some interesting pages describe how the medieval masons divided the circle with such precision that in curvilinear traceries the interlocking mouchettes, paisley-like leaf shapes, were articulated around centres that were not even carved in the stonework.

In trying to be thematic rather than chronological, there is a risk that Cowen's thesis will not cohere, but he marshals his structure and the divisions within it with insightful clarity. In the chapter dealing with iconography, he cites a range of narrative cycles taken from the zodiac, wheels of time and fortune, the Creation, the Last Judgment, the Tree of Jesse, the New Jerusalem, morality cycles, and the lives of Christ and Mary. The section on the Imago Mundi at Lausanne Cathedral particularly repays attention. Perhaps, in a future publication, the author might choose to contrast a small group of windows in greater depth. By covering so much ground in this book, he inevitably sacrifices much of his detailed knowledge in the interests of a general readership and space restrictions.

This book opened my eyes to a glorious aspect of art and architecture that I thought I already knew. As St Hugh of Victor advised Abbé Suger: "The foolish man wonders only at the beauty in those things; but the wise man sees through that which is external, laying open the profound thought that is divine wisdom."

Mark Cazalet is painting a chancel ceiling for St Alban's Church in Romford, Essex.