If you have ever come to visit us here at Old City Hall, one thing you got to admire is the Old City Hall building. From its granite pillars to its square shaped dome, you have got to admire that French Second Empire style.
While admiring the building you might notice that the dome on top of the building is made of copper, not black slate, which does not match the French Second Empire style.
It turns out it used to be black slate. Then sometime in the 1920's, it changed from slate to copper.
However, there is no written record of this happening, but there is photographic evidence of the change. Without written record of the change we don't know why someone would want to change the historical integrity of building.