LONDON.- As it did 20 years ago with the introduction of a new balanced warm and cool tungsten illumination, the National Gallery, London, is once again proving itself a leader in the area of lighting systems for galleries. Over the next two years, LED (Light Emitting Diode) lighting will be installed throughout the Gallery, which will significantly reduce its carbon emissions and improve the quality of light in the picture galleries. The Gallery is the first institution in the world to use these lights in conjunction with a system that automatically adjusts external roof light blinds according to the amount and angle of sunlight. This ensures that only diffused light is present in the galleries through UV-filtered roof light glazing. The new LED lighting system will slowly augment the natural light as needed, as opposed to the old system that can be distracting to visitors by going on and off abruptly. This is poss