William Herschel discovered NGC 4521 = H II-849 = h1326 on 20 Mar 1790 (sweep 954) and logged "pB, vS, lE, SN." JH recorded "pB; pmE; pgbM; 20" long, 12" broad; a * 9m near. His description matches NGC 4521, but his position is 20' too far south. Because of the discrepancy with his father's position, JH listed it as a "Nova". In the NGC notes, Dreyer notes that "h1326 = II 848, but h's P.D. Is wrong; d'Arrest's adopted".

See notes for NGC 4512 = h1321, which may be identical to NGC 4521.

400/500mm - 17.5" (4/15/93): moderately bright and large, edge-on 4:1 NNW-SSE, very bright core, faint stellar nucleus, very thin tapering extensions. Located 2.0' SSE of a mag 10 star. A mag 15 star is just 30" E of the southern extension. NGC 4481 lies 20' WNW. UGC 7700 = (R)NGC 4512 located 4' SW was not seen.

600/800mm - 24" (5/30/16): at 225x; moderately bright and large, edge-on 4:1 NNW-SSE, 1.2'x0.3', sharply concentrated with a very small bright core. A mag 11 star is 2' NNW and a mag 15.2 star is 1.4' SSE. Forms a pair with much fainter UGC 7700 4' SSW. Brightest in a group including NGC 4510 19' NNW and NGC 4545 27' SSE. UGC 7700 (misidentified in all modern catalogues and most online sources as NGC 4512) appeared very faint, fairly small, 24" diameter (only the central region seen), very low even surface brightness.

Notes by Steve Gottlieb