About the Library

Dome

Soaring over 40 metres above the floor, the dome is one of the most arresting features of the Main Library.

At the core of the dome’s design is its iron frame, a prefabricated structure that was ordered from England. It consisted of 32 iron ribs with a plaster infill. The circular space that its diameter encompasses was a span unprecedented in Canada when the Library opened in 1876.

While the Main Library escaped the 1916 fire that destroyed the rest of Centre Block, its dome was at the heart of a fire in 1952. The flames were contained to the dome, but the Library suffered heavy water damage. During the four years of renovations that followed, the dome was totally rebuilt using moulded plaster, as in the original. It was crowned with a replica of the lantern, the raised structure with its chrysanthemum-like pattern that sits atop the dome, overarching the immense, open space.

The dome spans the Library’s reading room. Supporting it structurally are 16 exterior flying buttresses which counteract the lateral thrust of the dome upon the walls. Inside, pairs of diagonal ribs, which fan out from marble columns to create a patterned web around the upper portion of the dome, provide further reinforcement.

The Library dome was once again renovated as part of a full restoration of the Library from 2002 to 2006. The gold leaf, which caps the dome’s lantern, was returned to its original shine, while the ribs radiating from it were painted a hue of blue characteristic of Victorian times, bringing it back to its distinctive appearance of 1876.

Details

• The dome’s iron frame was the first of its kind in Canada.
• The interior of the dome is made of wood lath covered with lime plaster.
• The windows of the dome allow natural light into the reading room.
• During the renovation of the early 2000s, the wrought-iron trusses of the dome were cross-braced against possible seismic activity. Earthquakes have since shaken the dome, without damaging it.