Abstract: The electric incandescent lamp according to the invention has an annular mirror coating on a hemispherical portion of its lamp envelope and a filament arranged zigzagwise between supporting points which are located on the surface of an imaginary cone. The filament is situated outside the part of the lamp vessel provided with the mirror coating. The lamp is particularly suitable for use as a traffic signal lamp and produces together with an external paraboloidal reflector a light beam of high luminous intensity at the center and in directions enclosing a small angle with the axis of the beam, as a result of which the lamp may be designed for a comparatively low power.