The American Philosophical Hall Library contains 350,000 volumes of periodicals, seven million manuscripts, about 150,000 photos and images and thousands of audiotapes. Among these books contain the first edition of Sir Isaac Newton’s Principia, Thomas Jefferson’s Notes on State of Virginia, Darwin’s Origin of Species, an elephant folio of Audubon’s Birds of North America and imprints of Benjamin Franklin. The manuscripts collection ranges from eighteenth-century natural history to the development of computers and medical sciences.