in some embodiments as in the case of web surface portion 60 although fig3 shows a planar surface for purposes of illustration only extension surface portion 62 may be curved or planar or a combination thereof preferably extension surface portion 62 is substantially planar an outwardly directed normal 78 to extension surface 62 has a downwardly directed component by outwardly directed what is meant is a normal directed away from a vertical plane intersecting root 18 preferably and as best shown in fig6 angle u03b2 between surface normal 76 and surface normal 78 lying substantially in a vertical plane through both web surface portion 60 and extension surface portion 62 is preferably less than about 30 u00b0 but greater than about 15 u00b0 more preferably less than about 25 u00b0 but greater than about 20 u00b0 thus the flow of glass over web surface portion 60 u201c breaks u201d at line 74 and changes direction as it flows onto and over extension surface portion 62 this can be seen from fig5 where angle u03b2 represents the angular change in direction of the glass flow in the vertical plane containing surface normals 76 78 from the flow over web surface portion 60 represented by arrow 75 to the flow over extension surface portion 62 represented by arrow 77 to ensure that the sheet of flowing glass is formed substantially flat the inner edge 80 of web surface portion 60 forms a common line of intersection or draw line with the inner edge portion of an opposed web.