This internationally known rare book library contains more than 400,000 books, more than seven million manuscripts and 100,000 pieces of sheet music. Exhibits vary throughout the year. On permanent exhibit is the Gutenberg Bible (printed before 1456) and John James Audubon's "Birds of America" prints. Exhibit hall hours are Monday - Friday, 9 am - 6 pm and Saturday, 9 am - 1 pm. Public tours are available every Friday at 2 pm or by appointment. Admission is free.