AMPHIBIOUS UNORTHODOXY: The Spencer-Larsen S.L.-12C, which has a four-cylinder Menasco in the hull driving a pusher propeller through gear transmission. Two main wheels of the tricycle undercarriage are mounted in the tails of the floats and retract with the floats. Constiuction is mainly of wood. Data are: span, 40ft.; wing area 164 sq. ft.; weight empty, 1,600 lb.; and gross weight, 2,200 lb.