The Wagner Free Institute of Science developed plans for a historically compatible lighting system and electrical upgrade for its three-story, 19th-century exhibition hall, which houses an extraordinary collection of natural history specimens, including mounted birds and mammals, fossils, dinosaur bones, and the first American saber-toothed tiger. Fluorescent fixtures badly compromise the historic integrity, aesthetics, and visibility in the hall, which constitutes the National Historic Landmark's most important public space. The project team included lighting designers with expertise in illumination for historic sites and museums, as well as an electrical engineer, an historic preservation architect, and a collections conservator. The new electrical systems will be sustainable and will minimize heat and light impact on collections. The introduction of professional museum lighting to the exhibition hall will serve to transform the visitor experience and will support new technologies that the present system cannot (including sound), providing new interpretive possibilities for the organization.