Wednesday, January 20, 2010

The Flying Buttress

The arch, which gives its name to architecture, produces an aesthetic form by harnessing practical intellect. This combination of a feeling, difficult to capture conceptually, and an intellectual force, the astute understanding of the play of physical forces, has always appealed to me in whatever field. Modern structural steel came into use in the nineteenth century and produced the first skyscrapers. After that all things became possible in architecture. Quite wonderful buildings still rise all over the world, but the interesting innovations the past produced by limiting the means to wood and stone have become less visible. Good architecture, nowadays, is a matter of money and taste.

My own interests date back to childhood when, at my grandmother’s house, aged four or five, left alone in a living-room-plus-library for a nap, I found a fascinating book of architecture filled with floor plans and architectural drawings—nothing like children’s books—and I fell into a life-long fascination. Later yet once I read a book on the arch—and its absence, for instance—in pre-Columbian American architecture. And then, while in Germany as a soldier, I spent my free time traveling all over Europe to haunt the great cathedrals. The Gothics were my favorites—and these feature that wondrous innovation, the flying buttress.

This drawing of a buttress at the Reims Cathedral is from an album of drawings by Villard de Honnecourt from the period 1230 - 35 obtained from Wikipedia here. This flying buttress has two wings, you might say. The interior of the cathedral is to the right; the buttress is outside under the open sky.

This elegant form came about because architects of that period (roughly the twelfth and thirteenth centuries) wished to build open cathedrals, the interior entirely hollow; “soaring” is often the word applied to capture the feeling we have as we look up into the dark immensities above. To get the open space, the ceiling could no longer be held up by a forest of massive interior columns. But, as a consequence, the weight of the ceiling used to cause the outer walls to push, to cave outward; if this was left uncorrected, the building could collapse. Two possibilities existed to correct this: to build very thick walls with very narrow or no openings at all. But the architects wanted lots of light to enter from without. Therefore they piled masses of stone on the outside of the walls to buttress them—not all the way up to where the windows were, but thickly at the bottom.

The flying buttress emerged later as a deeper understanding of the underlying physical forces developed over time. A flying buttress carries the weight of the roof and ceiling outward, away from the walls, in one or two flights, and lets it rest on the solid ground a distance away from the building itself. The concept of  “pushing against” had to be replaced by the concept of “carrying away.” This gives Gothic cathedrals their unique and wondrous look in which aesthetic values serve the needs of engineering and engineering transcends its function and becomes beautiful. I’ve long cherished this architectural structure as a visible symbol of the body-soul interaction. The next image is that of Notre Dame in Paris. It was begun in 1160 and completed in the 1240s; cathedrals, alas, are never really finished. Notre Dame was one of the first structures to use the flying buttress.
Notre Dame picture courtesy of Andy Hochhalter here.


  1. Could those ancient builders of soaring cathedrals have something in common with our modern architects? It seems hard to imagine that the ancients and our modern engineers, those who built the Dubai skyscraper tower, for example, could have been driven by identical impulses. And yet, competition to build "the biggest," the "tallest" or most awe-inspiring must have been part of the cultural motivations of both old and modern designers. My difficulty in reconciling these two inspirations comes from the purposes that moved this same intellectual capacity. We direct our awe at commercial or banking fortresses while architects a thousand years ago expressed their worship of a higher power in creating those magnificent churches and cathedrals all over Europe.

  2. I like Brigitte's question; there's a lot of food for thought in it.

    The nineteenth century Gothic revival in Britain began in part because of William Whewell's Architectural Notes on German Churches (available online here). Before then Gothic architecture had been regarded as relatively irrational -- thrown together and making no sense. But Whewell argued that it was rigorously rational -- it was dominated by the Idea of the Vertical. As he put it (p. 318), "The Gothic architect restored the reign of order, and rallied these vague elements [of previous architecture] in a vertical line. A new thought, a new idea, was infused into the conception of such members, which at once gave them connexion and fixity."

    In that way I think it makes sense to say that there is something common to the cathedral-maker and the skyscraper-maker -- they are both dominated by the vertical line. But I suppose different people can be interested in the vertical in different ways -- some because it can be used to convey that there is something much greater than we are (God in the Heavens, soaring and sublime), and others because it can be used to convey how great we ourselves are (which may be more or less harmless, but in the worst case is just a re-telling of the story of the Tower of Babel).