before explaining the present invention in detail , it is to be understood that the invention is not limited in application to the details of construction and arrangement of the parts illustrated in the accompanying drawings , since the invention is capable of other embodiments and of being practiced or carried out in various ways to produce elements for other end uses . also , it is to be understood that the phraseology employed herein is for the purpose of description and not of limitation . while the apparatus of the invention has particular utility in the processing of glass for forming fibers or filaments , it is to be understood that the apparatus may be employed for producing fibers from other materials . referring to the drawings in detail , fig1 illustrates a fiber forming operation . mineral material , such as glass , is maintained in a molten condition in bushing or stream feeder assembly 10 from which a plurality of streams of material is emitted from orificed tips or projections 22 depending from the bushing floor . bushings which do not have but tips have an orificed bottom wall can also be used . the streams of glass form cones 24 at the discharge end of the orificed projections . glass fibers 26 are attenuated from the cones of molten glass . the fibers are coated by size applicator 40 and gathered into a strand by gathering shoe 44 . the strand is then collected by winder assembly 50 . the strand is reciprocated by traverse 58 for collection on the winder collect 52 . to control the glass fiber forming environment , blower means 30 is provided . it is also within the scope of the present inventon to use conventional fin shield glass fiber forming environment control apparatus rather than the blower apparatus shown . the bushing assembly of fig1 is shown in greater detail in fig2 through 4 . the bushing chamber comprises a bottom wall 12 , upwardly extending end walls 32 and upwardly extending sidewalls 14 . the end walls have electrical terminals 34 extending therefrom . the sidewalls each have an outwardly extending flange 16 at the upper edge thereof . the bushing bottom wall , end walls , sidewalls , and flanges are constructed of an electically conductive metal such as a platinum / rhodium alloy . the bushing is provided with means for establishing a desired electrical current flow pattern through the flange to establish the electrical current flow pattern of the bottom wall and sidewalls . as shown , the addition of material to the flange modifies the current flow distribution such that relatively more current flows through the corner regions and relatively less current flows through the central region of the bottom wall . by such modification the heat pattern of the bottom wall is controlled to that desired . fig2 shows electrically conductive material 18 that has been added to only a portion of each flange 16 to lower the electrical resistance of said portion . in this embodiment , the material is added only to the outer area of each flange along the central region of the length of said flange . the shape of the ends of the material is designed to avoid hot spots . a tapered shape as shown can be used . as can be seen in fig4 the material 18 is positioned on the bottom surface of the flange although it could be on the upper surface or made an integral part thereof . adjacent the bottom surface of the material and the flange is cooling means 20 . as shown , the cooling means can be a water cooled tube which conveys excess heat away from the outer edges of the flange to prevent glass from leaking from the bushing during operation . because of the increased flow of current through the flange with the added material , it is necessary to supply slightly more current to this bushing than to a prior art bushing to maintain generally the same bottom plate temperature . this additional current can result in excess heating of the flange , and in particular , of the material added to the flange . the cooling means removes any excess heat from the flange and material so that such heat does not adversely affect the bottom wall heat pattern by conduction of heat from the flange and material through the refractory material surrounding the bushing to the sidewalls and bottom wall . fig5 illustrates an electrical current flow pattern in a prior art bushing . the current flows from terminal 34 of end wall 32 through bottom wall 12 , sidewalls 14 and flanges 16 to the terminal at the other end of the bushing . the current flow in the corner region of the prior art bushing bottom wall and in the end regions of the sidewalls at the end wall region is small . since the current flow is small , the heat generated in these areas will also be less than that in other areas of the bushing . this can result in cooler areas in the bushing , and thus , poor bushing performance . cooler areas in a bushing can also result in production interruptions . fig6 illustrates an electrical current flow pattern in a bushing resulting from use of the present invention . the current flows from terminal 34 of end wall 32 through bottom wall 12 , sidewalls 14 and flanges 16 to the terminal at the other end wall of the bushing . the current flow illustrated in fig6 is quite different from that shown in fig5 . this difference in current flow is due to the conductive material 18 added to a portion of each side wall flange . material 18 reduces the electrical resistance at the center portion of the outside of the flange , and thus , additional current flows from the terminal through the corner regions of the bottom wall and the end regions of the sidewalls . this increased current flow results in improved bushing heat patterns . specific design dimensions of the material will depend upon the size and shape of the particular bushing . for example , the height of the sidewalls , the length and width of the flanges and the thickness of various portions of the bushings must be considered when specifying the material to be added to the flange . it is , of course , within the scope of the invention that the material can be added as an integral part of the flange during construction of the bushing . the following is a specific example of a bushing according to the invention . the bushing is generally of the same configuration as shown in fig1 - 4 . the flange along the length of the bushing is about 43 centimeters in length and about 3 centimeters in width . the sidewalls and flanges are both about 0 . 05 centimeters in thickness . the material added to the center , outside region of the bottom of the flange is shaped as shown in fig2 . the ends of the material are tapered to avoid hot spots during operation . the material is about 30 centimeters in length at its longest portion and about 18 centimeters in length at its shortest portion . the material is about 1 centimeter in width and has a thickness of about 0 . 06 centimeter . with such a construction the bushing has an electrical current flow distribution is shown in fig6 . it should be noted that the added material does not extend the length of the flange . if the material extended the length of the flange , or if the flange were merely widened , or if the flange were merely thickened uniformly , the current flow pattern would not be as shown in fig6 . having described the invention in detail , it will be understood that such specifications are given for the sake of explanation . various modifications and substitutions other than those cited may be made without departing from the scope of the invention as defined in the following claims . the present invention would be useful in the mineral fiber forming art and , in particular , in the glass fiber forming art .