In employment of artificial lighting, art museums have regrettably suffered, during the past half century from accelerated obsolescence of light sources, lighting equipment. and of even more rapidly developing means and materials for installation. There is am increasing need for technically trained liaisom capable of developing further the communication betweem illuminating engineering and architecture. This is essential to coordinate systematically the lighting with overall cubic space allocation, proposed circulation of occupancy and viewing order of exhibits, together with climate control -- not only for visitor comfort but for the preservation of collections as well. If the artists' meaning is to remaim legible and to be seen at its best, it should be seen in the same illumination under which it was created. Except when their purposes called for some special lighting conditions, the creators of great paintings, historically used natural light either indoors or out. Lighting engineers cam at least supply the best available simulation of natural illumination which can be accepted under indoor conditions; with flexibility for glare-free presentation and for tonalities of special emphasis within natural limits (4000° to 7500° K), and the accenting of candle power as well. Flexibility of lighting so often cited as the chief requirement in art museums, means much more than convenient location of spot and flood lamps; it also means adj ustment to safe conditions of exposure and the interplay of diffuse and concentrated light as found in nature. -- AATA