A bow window or compass window is a curved bay window. Bow windows are designed to create space by projecting beyond the exterior wall of a building, and to provide a wider view of the garden or street outside and typically combine four or more casement windows, which join together to form an arch, differentiating itself from the more common bay window which typically features 3 casement windows.
Bow windows first appeared in the eighteenth century in the United Kingdom, (and in the Federal period in the United States).
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