The astronomers have never been in a cave like this before. Some of their colleagues have: decades ago the anthropologist Félix Regnault explored the depths of Lombrives, a system of caves in the Pyrenees famous for sheltering a group of Albigensians from their bloodthirsty pursuers in the 13th century. The Albigensians had wriggled through tight, twisty passages into a vast womblike void in which, by flickering torchlight, they could see glinting spires of limestone and the still green waters of a lake. The ceiling was out of sight in the gloom. Researchers later confirmed that this chamber, which came to be called “The Cathedral”, is the size of Notre-Dame. Regnault would eventually find a deeper, further system of tunnels that led to a chamber four times that size, a cavern so big it seemed bigger than the world outside it. News of this probably reached the astronomers when they were children, and maybe they dreamed of seeing that green lake some day.
But in those days before boutique tours and climbing gyms, speleology was a discipline for eccentrics. The first time the astronomers saw an interior the size of the galleries in Lombrives it was in the Hall of Machines at the 1889 World’s Fair in Paris.
The Hall of Machines was a long iron-and-glass pavilion, with a vaulted ceiling like a Gothic cathedral’s, except that the trusses that supported those vaults started high up their supporting pillars, which, close to the ground, seemed eerily light and insubstantial. It was therefore impossible to figure out the exact scale and weight of the building. It was the largest enclosed space on Earth at the time, and like Lombrives it seemed bigger and more capacious than the world outside.
The Hall of Machines was a new development in iron construction, but the astronomers have grown up with the technique and are probably familiar, at least in concept, with the vertiginous awe that iron-and-glass buildings provoked in people. In 1851 Lothar Bucher, a future lackey of Otto von Bismarck, visited the Crystal Palace in London and wrote this about the iron lattice that held it up: “We see a delicate network of lines without any clue by means of which we might judge their distance from the eye or their real size…It is sober economy of language if I call the spectacle incomparable and fairylike. It is a Midsummer Night’s Dream seen in the clear light of the day.”
Massive buildings out of all human scale are not new. What is new, in the astronomers’ day, is the lack of any attempt to relate them to the human scale. The transgenerational train of architects who built St. Peter’s Basilica were all very careful to relate its maddening scale to the size of observers’ bodies: the statues built along the nave and around the choir are all slightly larger than life-size, and twin statues located directly above each of them are three times that size. The building slowly massages the viewer’s eye until it’s ready to conceive of the divine. Nothing of the sort in the Hall of Machines, which has stripped away all those statues of saints and allegories and revealed the building’s skeleton, as mute and inhuman as the limestone walls of Lombrives.
Stripping the crinolines and hoopskirts from the building. About the time of the 1889 World’s Fair, the German art critic Max Liebermann wrote about Edgar Degas that “he seems…to see the nascent prostitute in the young dancer”. That’s to say that Degas saw primarily artifice, not beauty, when he went to the ballet: straining cablelike muscles and bright synthetic makeup, and above all a pneumatic pantomime of lust, instead of the grace and elegance that sent other critics into rhapsody. He painted these things as impassively as he could, in a cold, heartless frame that he inherited from photography and Japanese prints. Degas’s point is that the body’s systems do not look at all “human” when you examine them closely. Years later the architecture critic Sigfried Giedion will identify this point of view with the one that created the Hall of Machines.
People had been scared of revealing the flesh of the building for years. The architect Henri Labrouste designed a massive glass-and-iron wall for the Bibliotheque Nationale de France, but in the completed building it is covered with a literal curtain, like a woman in a cartoon throwing clothes up over a dressing screen. All through the history of glass-and-iron construction you can see decoration frothing at the mouth in an attempt to cover it up. Volutes, allegorical statues, frescoes, plush carpets—distractions creep over every surface. But the metallic skeleton is always there.
In its earliest stages, before the department stores and train stations, before the Hall of Machines, large enough to generate its own weather, this metallic skeleton covered greenhouses. In the 1830s, Charles Rohault de Fleury built greenhouses in the Jardin des Plantes, with wrought-iron cages supporting glass roofs so that plants could bloom underneath them year-round in circumvention of the natural order of the seasons. The novelty of this approach was such that they were called the “Gardens of Glass”. Joseph Paxton, the architect of the Crystal Palace, was also a gardener, “more accustomed to work with plants than with iron”.
Pierre Fontaine’s Galerie d’Orleans, a wing of the Palais Royal, was completed in 1831, when anyone over 50—the astronomers’ grandparents—could still tell you about life under Louis XVI. Its severe Doric columns are like ghosts from that world, but above the architrave those columns bloomed into an iron-and-glass roof. Giedion writes that the roof’s diffuse glow created “an impression of freedom and openness, as though one were out-of-doors yet shielded from the elements.”
An impression of freedom and openness.
And here the astronomers are: in a mushroom garden on the moon.