As sub-librarian at the Bodleian Library, he was chief architect of the Summary Catalogue of its MSS, which was one of his two main achievements. The other was his three-volume catalogue of books printed in Oxford (1895–1931). Among his other publications was a bibliography of Henry Sacheverell (1884). In 1912, Madan became Bodley's librarian, and in 1914 he established the Bodleian Library Quarterly (1914). He was active in the Bibliographical Society and a founding member of the Oxford Bibliographical Society.
From The Oxford Companion to the Book in Oxford Reference.