A method of reducing the volume of float bath atmosphere lost from an opening in the exit end of the float bath is described. The method comprises directing a first jet of fluid having a first jet velocity followed by a second jet velocity towards a plane a conveyance for a float glass ribbon. An obstruction in the path of the first jet of fluid causes the jet to change from the second to a third jet velocity. The obstruction may be a portion of a roller positioned outside the opening or a float glass ribbon that has been formed on a surface of molten metal contained in the float bath that has subsequently been transferred through the opening. A float bath having sealing means to reduce atmosphere loss from an exit of the float bath is also described, as is an assembly useful in carrying out the aforementioned methods.