The PH 3/2 Glass Table Lamp from Louis Poulsen is a design steeped in the actual science of light. It is based on the principal of the reflective three-shade system, developed in the 1920's by Poul Henningsen. Structured to direct the majority of light downward, an eventual shade shift from metal to glass extended the range of illumination. Three-layered handblown glass shades are sandblasted on the underside, providing soft and even distribution of light.