George Johnstone Stoney, Lord Rosse's assistant, discovered NGC 1685 in January 1850. It was found while examining the NGC 1684 field and labeled as "Delta" on his sketch. The NGC position is 2.7' too far north, though the sketch makes the identification certain.

400/500mm - 17.5" (12/23/89): very faint, small, slightly elongated NW-SE, almost even surface brightness. A mag 14 star is off the SE edge 1.0' from center. NGC 1684 lies 9.5' S.

Notes by Steve Gottlieb