Abstract: A high pressure sodium lamp includes discharge vessel (20) which is enclosed with intervening space (1) by an outer bulb (10), which space contains a gas-fill with at least 70 mol. % nitrogen gas. Electrodes (30a, 30b) are positioned in the discharge vessel (20) and are each connected to a current supply conductor (40a, 40b) which issues from the discharge vessel (20) at a respective end (21a, 21b) thereof. The discharge vessel (20) has between the electrodes (30a, 30b) a central portion (22) with length L and volume V. The discharge vessel (20) contains an amalgam containing a weight m.sub.Hg of mercury and a weight m.sub.Na r. of sodium, whereby the following relations are fulfilled: ##EQU1## in which m.sub.Hg and m.sub.Na are expressed in mg, and L and V are expressed in cm and cm.sup.3, respectively.

Abstract: Tools for the handling and shaping of glass, such as dies, moulds, shears. Sticking of the glass to the tool is prevented by the presence, at the tool surface, of a layer which has a low intrinsic strength with respect to the glass. This layer may be present as such or may be produced after oxidation. A number of possible materials are: boron carbide, Ni-Cr-B-alloys, tantalum boride.