John James Audubon's Birds of America appeared in 87 parts over a twelve year period (1827-38). It is known as a "double elephant folio" because of the enormous size of the paper on which it was printed and is considered one of nineteenth-century America's greatest works of art, natural history, and bookmaking. A permanent exhibition case displays one volume of Penn's six volume set of the Birds, a gift of Edwin H. Vare, Jr. in 1957-59. The page opening from the volume on display is changed on the second Wednesday of every month.