The early phase of "Middle Pointed" style (late 13th century) is characterized by "Geometrical" tracery – simple bar-tracery forming patterns of foiled arches and circles interspersed with triangular lights. The mullions of "Geometrical" style typically had capitals with curved bars emerging from them. "Intersecting" bar-tracery (c.1300) deployed mullions without capitals which branched off equidistant to the window-head. The window-heads themselves were formed of equal curves forming a pointed arch and the tracery-bars were curved by drawing curves with differing radii from the same centres as the window-heads. The mullions were in consequence branched into Y-shaped designs further ornamented with cusps. The intersecting branches produced an array of lozenge-shaped lights in between numerous lancet arched lights."Y-tracery" was often employed in two-light windows c.1300.