William Herschel discovered NGC 4818 = H II-549 = h1484 = h3445 on 3 Mar 1786 (sweep 536) and recorded "pB, vL, lbM, iF." JH logged from Slough "pB; pL; lE in meridian; vgbM." and from the Cape of Good Hope, "B; L; mE in meridian; gpmbM; 3' length."

400/500mm - 17.5" (5/17/90): fairly bright, fairly large, very elongated 4:1 N-S, broad concentration. A mag 13 star is just off the south edge and a fainter mag 14 star is 1.4' E of center. A double star lies 5' SW (mag 11/13 at 19" separation). A mag 10 star lies 6.5' WNW.

Notes by Steve Gottlieb