see the Home Craftsman 20 (March April) 1951 pp 45-46
[] Jeff Joslin, an official of the Old Woodworking Machines website (and advisory editor for my online History of the Amateur Woodworking Movement: "Coplanar" means "lying or occurring in the same plane; used for points, lines, or figures."
see discussion in the piece on the Evolution of the Tilting Arbor Saw