Montreal Biosphere
The steel-framed sphere was covered with transparent acrylic panels. Unfortunately the system never worked properly. Instead valves were installed in the center of the acrylic panels for the pavilion to ventilate. The pavilion was originally designed to be dismantled. However, to cut cost, the metal tubes were welded and not bolted as proposed by Fuller. This made the structure impossible to dismantle. So after the fair ended, the US government donated its pavilion to the City of Montreal....