A display lamp includes an electric light bulb disposed within a cylinder supported in a substantially vertical orientation. A light-transmitting container of water or other light-transmitting liquid is supported on the top of the cylinder. A dispenser of liquid is disposed above the container for dropping droplets of liquid onto the surface of the liquid in the container for disturbing it. The light shines through the vessel and the liquid and its disturbed surface and onto an associated display surface, such as an adjacent wall or ceiling, for producing thereon a visual wave pattern which moves in accordance with the disturbance of the liquid surface.