William Herschel discovered NGC 3394 = H II-872 = h764 on 3 Apr 1791 (sweep 1004), along with III-881 = NGC 3392. He recorded "F, cL, iR" and his relative offsets (21 sec in RA and 2' in dec) matches the pair.

John Herschel placed h764 = NGC 3394 24 seconds of RA east of h763 = NGC 3392, instead of 24 seconds of RA west. This caused the NGC RA to be 44 seconds east of the true position of NGC 3394.

400/500mm - 17.5" (4/6/91): fairly faint, moderately large, diffuse, slightly elongated, low surface brightness. Forms a pair with NGC 3392 4' NE.

Notes by Steve Gottlieb