Five circular skylights, with colors purple, teal, green, aqua and orange, cast moving spots of light on to the floor of the main library room. The orange skylight is used for the dial, while the others are decorative. Each day at solar noon, when the sun is highest in the sky and is due south, the orange spot of sunlight aligns exactly with a north-south meridian line marked on the carpeting. The spot’s position on the line varies with the seasons as the sun moves north and south through the sky. Circles are marked for the spot positions on (a) the summer solstice (about 21 June), (b) the equinoxes (about 20 March and 23 September), and (c) 12 August, the opening day for the new library in 2006.
A small brochure about the dial is available from the librarians.