Music of Ireland
In 1851 he was elected a member of the Royal Irish Academy and, on the founding of the Catholic University of Ireland in 1854, he was appointed professor of Irish history and archaeology. He worked with George Petrie on the "Ancient Music of Ireland" (1855). In 1852, he and O'Donovan proposed the "Dictionary of the Irish Language", which was eventually begun by the Royal Irish Academy in 1913 and finally completed in 1976.