1911 Encyclopædia Britannica/Camber

CAMBER (derived through the Fr. from Lat. camera, vault), in architecture, the upward curvature given to a beam and provided for the depression or sagging, which it is liable to, before it has settled down to its bearings. A “camber arch” is a slight rise given to the straight-arch to correct an apparent sinking in the centre (see Arch).