In the libraries of the Yale Center for British Art and the Kimbell Art Museum, Louis I. Kahn created spaces and atmospheres that are particularly conducive to reading about and viewing art. In these rooms, natural light combines with sympathetic materials and forms a timeless dance with thought and contemplation. This paper focusses on the unique library carrels which form the physical bridge between light and dark, inside and outside, and constitute a microcosm of Kahn's thoughts about reading, libraries and museums.