[PB.26L]                                                              [PB.26]								26
                                                                      
[Porta della Carta]                                                   	Tracery of Porta della Carta
                                                                      
[diagram] A  B  C                                                     			It is evidently derived from
                                                                      			a common 4 foil tracery
                                                                      			       only the cusp hollow
[diagram] D                                                           			         chamfered.
                                                                      [diagrams] A  B  C	     Its sub- divisions
                                                                      			   are shown by the
                                                                      			    rough figure opposite
                                                                      of which however the little shaded
                                                                           bit has was carefully worked. to show how
                                                                      rigorously the Italians adhered to their awkward
                                                                      system of considering the tracery perfect in
                                                                      int  itself and cutting in upon it by
                                                                      the arch line.  Thus . in this porta della Carta
                                                                      it will be well to draw the set of circles on
                                                                      on each side. and to give a large figure filled
                                                                      with the inner traceries . and then cut clean
                                                                      through it by the line of arch. as at D opposite
                                                                      So rigorously is this done that the commence
                                                                      ment of the parting of the trefoil 4 foil roll
                                                                      B. into its two forks is seen at x. and then
                                                                      suddenly stopped by the archivolts
                                                                      thus
                                                                      
                                                                      	[diagram]

[Version 0.05: May 2008]