Collection consists namely of prints, portraits and photographs of mathematicians collected by Dennis. Notable historic figures in mathematics are represented. Several published portfolios, including editions of David Eugene Smith's Portraits of Eminent Mathematicians, containing prints and biographical information on the mathematicians are also included. Plates appear to often come from published works and in some cases include portions of text from the book from which they were removed. Also a panoramic photograph by Fenner showing the attendees of the 1946 annual meetings of the American Mathematical Society, Institute of Mathematical Statistics, and Mathematical Association of America at Cornell University, photographed in front of Barton Hall.