ns, for example added for the heating up process.FIG. 1 shows a section of a cross section through a furnace volume; the hydrostatic pressure which is applied by the glass melt (9) to the side wall of the melting end (5) via the bridge wall (11) with the resting elements (11a) on the pressure element, which is in this case implemented as leading screw (13), is transmitted via a guide thread of the