 Its collections, consisting of over half a million volumes and three kilometers of manuscript material, encompass the broad areas of literature, history, art, theology, philosophy, technology and the natural sciences, and include large collections of emblem books, writings of and works about John Milton, and authors' personal papers.From the founding of the University Library into the twentieth century, rare materials were housed within the main stacks.Significant early acquisitions, now housed in the Rare Book & Manuscript Library, include the Richard Aron collection on German pedagogy (20,000 items), acquired in 1913; the H. A. Rattermann collection of German-American literature (7,000 items), acquired in 1915; the James Collins collection of Irish literature (over 7.000 items), acquired in 1917; the Julius Doerner collection on theology, history, and literature (50,000 items), acquired in 1918; and the Antonio Cavagna collection of Italian books and manuscripts (45,000 items), acquired in 1921.