From The New York Times, 29 Jun 1939: Prof. Harry Barnum. Mathematics Head of Robert College in Istanbul. Word was received here last night by the Near East College Association of the death yesterday in Istanbul, Turkey, of Professor Harry Huntington Barnum, head of the mathematics department of Robert College there. He was born sixty-one years ago in Van, Turkey. On graduating from Amherst in 1900 he became an instructor in mathematics at Robert College, where he remained except for a few years of graduate study in this country. He is survived by his widow, the former Anne Alvord of Danbury, Conn., and three daughters, Helen Barnum, an English instructor at the Woman's College of Istanbul, and Eleanor and Ruth Barnum, who are connected with Robert College.
From: Burials in the American Section of the Protestant Cemetery, Ferikoy-Istanbul Turkey: Researched and Compiled by Barbara Dobbins Title. Barnum, Henry Huntington, Math professor, son of Missionaries Henry & Helen Barnum; b 24 Dec 1877/78, d 28 Jun 1939, Istanbul. Wife: Anne A. Barnum.
He is listed as a passenger in 1913 on a voyage from Liverpool to New York.