An arch is an opening or frame that is either load-bearing or decorative. A true brick or masonry arch is a composite structure, whose wedge-shaped constructional blocks are disposed radially and held together in compression. A blind arch refers to an arch which is filled in. Blind arches are frequently used for decoration on the external walls of buildings.
The two Carnegie Libriaries in the Waterloo Region which used arches were the Waterloo and Berlin (Kitchener) Library. These two libraries were the largest in the regions and recieved the largest grants.