 From 1922 to 1946 he was the director of Princeton University's art museum.Mather was an editorial writer for the New York "Evening Post" and assistant editor of the "Nation"" (1901–1906) and art critic for the "Post" (1905–1906; 1910–1911); from 1904 to 1906 was American editor of the "Burlington Magazine"; contributed frequently, chiefly on art subjects, to the "Nation", the "Burlington Magazine", "Art and Progress", and other periodicals.He became editor of "Art Studies" in 1923.