NGC 684 is a spiral galaxy approximately 135 million light-years away from Earth in the constellation of Triangulum. It was discovered by William Herschel on October 26, 1786. Edward Swift, Lewis' son, found this galaxy again on 18 Jan 1890 while "searching for Swift's Comet." and it was reported as a new object in list IX-6.

400/500mm - 17.5" (12/8/90): fairly faint, fairly small, edge-on 4:1 E-W, even concentration, small bright core, stellar nucleus. Located 32' NE of NGC 672 in a group.

600/800mm - 24" (12/28/13): fairly bright, beautiful edge-on 7:1 E-W, 1.8'x0.25', sharply concentrated with a very small, very bright core and a faint stellar nucleus.