ones on the detailed drawing of the Reims elevations on the facing page, folio 31 verso). Geometrical tracery 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. Geometrical tracery is identified by the circular openings at the head of the arch of the window. A common composition is three lights beneath two circles and a third at the point of the arch; such an example can be seen along the aisle at Lincoln Cathedral Also at Lincoln Cathedral, the east window is an expanded version of this idea with two interior arches, a total of eight lower lights, four small circular lights topped with two larger circles to fill out the interior arches, and finally above all one large circular shape filled with seven smaller circular lights. Geometrical tracery, in its early stages, had a rule of equilateral law, where the tracery design follows the shape of the arch in an equilateral manner. Additional decorative elements can be implemented, such as foliation or the "spherical triangle". The use of spherical triangles is a later adaption and likely reflects religious significance. Curvilinear (flowing) tracery Second Pointed (14th century) saw Intersecting tracery elaborated with ogees, creating a complex reticular (net-like) design known as Reticulated tracery. Second Pointed architecture deployed tracery in highly decorated fashion known as Curvilinear and Flowing (Undulating). These types of bar tracery were developed further throughout Europe in the 15th century into the Flamboyant style, named for the characteristic flame-shaped spaces between the tracery bars. These shapes are known as daggers, fish-bladders, or mouchettes. Starting in the late 13th century and at the beginning of the 14th century, tracery took on more fluid characteristics. A common shape used in curvilinear