Notes, facsimiles on tracing-paper, correspondence, offprints, and manuscripts pertaining to the history of mathematics, assembled by Boncompagni with the help of his research assistants Filippo Ricci, Alarico Carli, Gaetano Giordani, Andrea Tessier, and Lodi, from libraries in Venice, Florence, Bologna, Milan, Monaco, and elsewhere in Europe. Offprints are mainly by late-19th-century Italian mathematicians, scientists, and historians of science.