Montreal Biosphère

The US Information Agency wanted a pavilion that would out-argue the Soviet Union's own Expo 67 exhibit simply by being the most advanced structure on the site, and gave Fuller a budget and a deadline rather than a design brief. His answer scaled up a principle he had spent two decades refining: triangulate a sphere's surface into a doubled lattice of steel struts and the loads that would buckle a single dome member instead distribute themselves across thousands, letting the structure enclose twenty storeys of unobstructed volume on four slender legs. An outer skin of inflatable acrylic cushions, each with a motorized sunshade, was meant to let the building regulate its own interior climate automatically as the sun moved — genuinely experimental technology that never worked quite as promised even before a 1976 welding accident set the whole skin on fire during renovation work, burning it away entirely and leaving only the steel frame, which nobody removed. Canada bought the shell from the departing US government in 1990 and, after a decade of study, converted it into an environmental museum that opened in 1995; UNESCO and other bodies have repeatedly cited the bare structure, not the vanished skin, as one of the twentieth century's defining works of engineering.