SYNOPSISIn this new lamp, the source of light is an ordinary domestic pearl bulb. In front of this is placed a bull's‐eye, which prevents the formation of an image of the pearl surface in the plane of the object and produces even illumination over the whole field of view. Since the illuminated surface of pearl glass is large, the whole of the aperture of any condenser is filled with light. The illumination is suitable for all objectives from 16 mm. (and more, if a low‐power substage condenser is used) to 2 mm., without change of bull's‐eye. Very exact setting of the direction of the beam of light is not necessary. It is claimed that this simple lamp gives the best possible illumination in all cases in which intensity of light is not the main consider