Final answer:
The question appears to refer to a historical event where a dome was reconstructed after an earthquake. The new design included structural enhancements to properly distribute weight and prevent future collapse. Separately, if referring to Montreal's Biosphère, its acrylic covering was destroyed in a fire in 1976.
Step-by-step explanation:
The cover of the partial dome in Montreal is not explicitly described in the provided references. However, the references do discuss various historical instances of dome destruction and reconstruction, such as the dome that was destroyed in the 558 CE earthquake. To rectify the structural issues, the architect redesigned the dome to be elevated by approximately six meters. This redesign included adding pendentives and ribs reminiscent of an umbrella's interior, which helped to distribute the weight across 40 windows, thus reducing the dome's overall weight. The newly completed dome stood at 55.6 meters high, with the weight of the dome correctly distributed on the walls, which continues to stand to this day. It is worth noting that the question may be referring to the Montreal Biosphère, which was originally the United States Pavilion during Expo 67. The Biosphère's acrylic dome covering burned in a fire in 1976, leaving only the steel lattice structure.