J.L.E. Dreyer discovered NGC 4018 on 26 Apr 1878 in the last observation of the cluster from Birr Castle. He placed it roughly 12' in PA 37° from NGC 4009 and it is labeled "Kappa" on the constructed diagram. The actual separation is 10' in PA 37°, although NGC 4009 is a star. The note"mE np sf, 2 st S" pins down the identification as UGC 6966 = PGC 37699. The two stars are ~3' SSE and shown too close to the nebula on the sketch.

400/500mm - 17.5" (3/19/88): faint, fairly small, edge-on NW-SE. A pair of mag 13 stars at 25" separation is located 3' SSE. Member of the NGC 4007 group with NGC 4022 7' SE.

600/800mm - 24" (3/22/14): fairly faint to moderately bright, moderately large, very elongated 3:1 NNW-SSE, 1.2'x0.4', broad weak concentration. NGC 4022 lies 7' SE.

Notes by Steve Gottlieb