A Return to the Source: Gothic Material and Meaning
by Daniel P. DeGreve, appearing in Volume 36
“The fashions have in fact done more mischief than revolutions. They have cut into the quick; they have attacked the osseous system of the art; they have hacked, hewn, mangled, murdered the building, in the form as well as in the symbol, in its logic not less than in its beauty. And, then they have renewed—a presumption from which at least time and revolutions have been exempt.”
-Victor Hugo, Notre-Dame de Paris, 1831
Set against the evening sky, the fiery plunge of the copper rooster that had crowned the lead-encrusted flèche of Notre-Dame de Paris seemed to herald a dreadful nightfall for the cathedral church, which for centuries has endured weathering, cataclysm, violence, and caprice.
Numerous government leaders, architects, academics, and critics seized upon the tragic conflagration of the medieval roof and nineteenth-century spire as an opportunity to overlay the Catholic sacred building with secular signification. Prompting the consequent volley of revisionist notions were intentions neither remote from the materialist motivations of the Revolutionary despoilers nor dissimilar to the vogue attitudes of the Baroque kings and clergy who preceded them.
The Controversy
The present crisis posed by the decapitated Cathedral of Paris resembles more acutely the predicament of the church’s dilapidated state in the first half of the nineteenth century when a thirty-year-old architect named Eugène-Emmanuel Viollet-le-Duc and his friend Jean-Baptiste Lassus won a competition to restore its west front. While the prevailing taste of the time favored Classical models, Viollet-le-Duc championed the rationale of medieval French architecture as a basis for modern French invention.
His talents and energies as a practicing architect were sympathetic to the deprecations voiced by Hugo, and his understanding of Gothic architecture profound. Yet, while Viollet-le-Duc went on to replace many of the missing or damaged details of Notre-Dame, his intention was not to return its appearance to a particular point in its history.
Instead, as he explained in his 1854 work, Dictionnaire Raisonne de l’Architecture Francaise du XI au XVIe Siecle, he wanted to correctively “reestablish it in a complete state which may have never existed at any given moment” using a practical methodology founded on archaeological accuracy, structural efficiency, reasonable adjustment, and historical integrity.
Following the collapse of Viollet-le-Duc’s controversially handsome spire, the ensuing debate focused on the appropriateness of rebuilding those parts which were turned to ash on April 15, 2019, versus replacing them with something expressive of a twenty-first century l’esprit nouveau. Proposals to alter essential components and experiential properties of Notre-Dame with modernist interpretations deny the actual historical continuity of custom and craft in favor of a historicist narrative of epochs.
The architectural historian Vincent Scully asserted in his Architecture: The Natural and the Manmade that “the fundamental reason for being of Gothic architecture, as of any architecture, is not technical or structural, or even functional in a restricted physical sense. It is symbolic; its builders want it to mean something.”
Like Viollet-le-Duc, we should seek to understand the meat and marrow of Notre-Dame as well as the building tradition from which the medieval church came to be so that we may work along its grain—and not against it—in the endeavor to make the edifice whole once more.
The organic and intuitive transformation of the basilica eventually led to Notre-Dame de Paris. Image: Daniel P. DeGreve
An Organic Building Tradition
The Gothic cathedral churches of the Ile-de-France are remote descendants of the early Christian basilicas of Rome. The Roman basilicas themselves were subjected to a series of earthquakes and fires during the Middle Ages, but they were successively rebuilt over the course of a millennium according to the same structural paradigm and material palette of stucco-faced clay brick walls, marble columns, and internally exposed timber roofs. Brilliant figural decoration spanning a basilica entrance façade was a foretaste of its dazzling, column-lined interior that filtered light from windows of translucent alabaster.
Paradigm shifts did occur over time, however, especially north of Rome, as a response to liturgical enrichment, monasticism, local craft, and sporadic contact with the Byzantine East.
Whereas the early basilica encompassed a series of parallel wall planes braced by the roofs that they supported, builders of later basilicas proliferated the use of transverse arches for spanning between these walls in order to improve their stability. The resultant compartmentalization isolated the damage to nave walls caused by disasters while poetically enhancing the processional rhythm and numerical symbolism of the church interior.
The compartments—or bays—between the transverse arches eventually made feasible for medieval builders the construction of masonry vaulted ceilings in primitive emulation of Roman Antiquity, which significantly altered the basilica church model.
The otherworldly grandeur of a continuous interior masonry shell, boldly painted and fire-resistant, discouraged a conservative rebuilding of the more barn-like and fire-prone basilicas throughout France.
In order to bear the weight of a masonry vaulted ceiling, walls were thickened. Windows became smaller and less frequent, but the contemporaneous development of stained glass made them gleam like inset gems. The increased heft was often accompanied by a continuous circuit of vaulted aisles and galleries that helped to counteract the compressive thrust of the round-arched nave and choir vaults.
Experimentation with the pointed arch—a triangulated form generated by the symmetrical intersection of two circles and related to the mystical vesica pisces—liberated bay geometry and vertical proportions, ultimately leading to its pervasive employment.
Builders subtracted mass from the walls wherever dead loads could be reduced with blind arcades and triforia. Through the concentration of bulk at the base of the building into which loads from the structural elements above were channeled, an equilibrium of forces and an economy of construction were progressively honed.
Opus Francigenum—French Work
This inventive momentum occurred in varying degrees throughout medieval western Europe producing outcomes that were regionally distinctive. Nevertheless, it was in the heart of northern France—the curbed and clumsy demesne of the French kings hitherto unremarkable for architectural advancement—where twelfth-century synthesis in several abbeys and cathedral towns near Paris fomented a marvelously cogent vision of the Christian temple.
Neither as an invalidation of older models nor as a ruptured departure from the preceding architectural convention did the opus Francigenum originate, but rather as an ongoing condensation aimed at reconciling the muscular monumentality of the cellular vaulted bay with the numinous luminosity and airiness of the planar basilica.
The language that historians call “Gothic” architecture was, both in its structural logic and symbolic meaning, the refinement of a grammar used to describe with anagogical radiance and augmented durability the image of the domus Dei as civitas Dei.
Unlike contemporary practitioners of zeitgeist who deliberately innovate within a self-referential conceit of modernity to achieve originality, medieval architects and builders intuitively innovated within a vibrant tradition of forms, materials, and meaning in order to represent the New Jerusalem—and achieved originality in the process.
Materials Substantiating the Immaterial
The Cathedral of Notre-Dame de Paris is a critical example of early French Gothic architecture, having been begun in 1163—some twenty years after the pivotal additions to the nearby royal Abbey of Saint-Denis— and completed a century later.
Unlike its slightly older peers in Noyon and Laon or the somewhat younger ones in Chartres and Reims, the new cathedral church of Paris was not warranted by the fiery destruction of an earlier structure, but by the grandiose vision of the bishop, Maurice de Sully.
The transcendent drama of dim polychromatic light and reverberant acoustics in Notre-Dame is grounded in an assortment of terrestrial materials that include limestone, sand, lead, iron, and wood.
Foremost among these is limestone, a sedimentary rock made up of calcite from the remains of marine organisms such as coral and mollusks. Relatively easy to quarry and soft to cut with the proper tools, it is also durable, making limestone a very suitable building material for dressing ashlar blocks and carving ornaments.
Derivative products include hydraulic lime mortar that sets wet as a soft and porous bonding agent, non-hydraulic lime putties, lime plaster, and air-setting hydrated lime.
Limestone ashlars joined with hydraulic lime mortar make up the faces of the walls and external buttress piers while their cores are filled with rubble and hydrated lime, which chemically reacted with the air to bond to the ashlars.
The cylindrical piers that bear the weight of the walls are built of solid stone. Lime-based cement coats the attic-side of each stone masonry ribbed vault to protect the construction while lime putty seals the lead-plated wrought iron pins that join the thin pieces of stone window tracery.
Sand and a variety of metallic oxide powders were combined to produce the stained-glass windows which illuminate the five-vessel church interior in neither a glaring nor even light, but rather punctuate it with a subdued glow of jewel-like reds and blues. Pliant lead cames clinch the individual pieces of glass while supple wrought iron rods embedded in the stone jambs and tracery hold fast the panes.
A thousand oak timbers dating from four separate construction campaigns once spanned the nave, choir, apse, transepts, and crossing to carry seamed lead sheets which sheltered the limestone vaulting.1
Fréderic Épaud, a specialist in medieval wooden frameworks, has recently dispelled in an essay several common inaccuracies regarding the size of the wood members and the age of the oaks from which they were hewn, citing a digital scan of the famous attic and surveys of comparable thirteenth-century French church roofs.
Likely harvested from less than ten acres of local forest, most of the oaks used at Notre-Dame were ten to twelve inches in diameter with an average age of sixty years. The larger old-growth oak, accounting for only three percent of the structure, measured about twenty inches across and was used for the horizontal tie-beams girding the topmost portions of the walls.
Each felled oak comprised a single structural member. The wood was not dried, but still green when hewn by axe and incorporated into the equilateral trussed lattices. Squaring by axe, rather than saw, preserved the natural curvature of the wood and maximized the amount of usable heartwood. Joined with pegs, the many pieces of timber framing and sheathing essentially functioned as a single unit with a consistent rate of shrinkage and movement.
The resultant structure was sturdy, yet relatively flexible in resisting the lateral wind loads enacted on its steep pitch.
Also framed in wood and clad in lead sheets was Viollet-le-Duc’s crossing spire. While he advocated a straightforward use of iron in theoretical designs for new construction, he embraced a traditional material palette for building a taller and more wind-resistant flèche.
Theory Without Practice
“Ars sine scientia nihil est.” These words were uttered by a frustrated French architect working in fourteenth century Milan, but the gist of his retort—art is nothing without the science to underpin it—well applies to proposals for re-roofing Notre-Dame with steel and glass shells or preserving the holes in the weakened ceiling vaults.
Limestone and wood are superbly compatible. Both consist of organic material and are inherently exempt from significant movement caused by normative thermal cycles or loading conditions. Neither material is excessively rigid so that the minimal movement naturally occurring in one can be absorbed by the other without damage.
Steel, in contrast to wood, is heavier, stiffer, and less stable. Its rate of thermally induced dimensional fluctuation is considerably greater, in fact, and the stress produced by its exertion on a limestone bearing structure can lead to cracking.2 While steel does not burn, it does lose its strength when exposed to the high heat of fire and can melt, exacerbating the resultant damage to a stone building. Timbers, however, will sustain surface charring before succumbing to combustion.
Durable limestone becomes susceptible to fissure when protractedly exposed to the heat of fire as demonstrated by the process of deriving quicklime. The quenching effect of water exacerbates the threat of material failure due to the leaching of salts deep in the stone, which can weaken masonry joints.
After careful monitoring over the course of years, the stability of the vaults will require mending with stones locked in compression. Any roof loads eventually placed on the limestone fabric of Notre-Dame will need to be carefully weighted to prevent further trauma.
During the nineteenth and twentieth centuries, the cathedrals of Chartres, Reims, and Cologne were retrofitted with innovative roof assemblies made of cast and wrought iron, precast concrete, and steel respectively. Although research has not revealed problems associated with these installations, they are relatively new and untested compared to the former “Forest” of Notre-Dame.
The medieval timbers of Notre-Dame’s “Forest” retained their strength for centuries. Photo: Notre-Dame de Paris
Following a fire, the iron roof of Chartres Cathedral was built in 1840. Photo: wikimedia.org/StuartLondon
A new wood-framed roof and spire for Paris will harmonize with the material properties of the building. Sources of comparable oak are available and specially trained carpenters with the Compagnons du Devoir are eager to ply the skills of their traditional craft.
A variety of intumescent coatings can enhance the fire resistance of wood while fire barrier compartments can contain the ravages of Vulcan without causing detriment to the building armature.
Dead Artifact or Living Symbol
In an exchange of letters published in Viollet-le-Duc’s 1846 manifesto, Du style gothique au dix-neuvième siècle, Désiré Raoul Rochette, Perpetual Secretary of the Académie des Beaux-Artes, opined that, “Monuments, which belong to a whole system of belief, civilization and art that has provided its career and accomplished its destiny, must remain what they are, the expression of a destroyed society, an object of study and of respect, according to their own merit or national interest, and not as an object of servile imitation and impotent counterfeiting.” Rochette, unlike Viollet-le-Duc, did not find Gothic architecture suitable for building modern churches.
Today, some architects and literati question whether it is even suitable to rebuild medieval Gothic churches in the Gothic style. Perhaps this quandary stems from an idolization of built patrimony as mere historical artifact from a “destroyed society;” nay a headstone memorializing, preferably without anachronistic creep, a defunct epoch that nobody living remembers—yet some would like to forget.
In his reply to Rochette, Viollet-le-Duc wrote, “To form a new art, we need a new civilization, and we are not in this case. Architecture is of all the arts the one that proceeds the most by transition, and that is very simple; but when the architect has corrupted the types, and let them loose, he must go back, return to his source.”
In the eyes of the new secular civilization trying to be born, the Christian message intrinsically signaled by the bones of Notre-Dame is an inconvenient memento from the old civilization being eclipsed. For the rest of us, we need to return to our source.
Indeed, we should endeavor to make Notre-Dame more beautiful—not as has been duplicitously promised, but as Viollet-le-Duc devotedly accomplished. Perhaps the time is come for remaking the sanctuary jubè to frame Holy Mass at the proper high altar.
With integrity, clarity, and consonance, natural elements and flora were selected, shaped, and incorporated into Notre-Dame. In her emergent shadow abided Saint Thomas Aquinas and Pérotin, witnessing the chivalrous construction being raised on the almond-shaped Ile de la Cité upon the Seine to the glory of God, the honor of the Queen of Heaven, and as crystalized conductus for the generations.