William Herschel discovered NGC 3510 = H II-365 = h813 on 11 Apr 1785 (sweep 396) and noted "F, mE, about 1 1/2' long but very narrow. On 24 Dec 1827 (sweep 115), John Herschel wrote, "pB; mE; nearly in meridian; bM." The assistants at Birr Castle made a total of 5 observations. For example, R.J. Mitchell, observing on 1 Mar 1854, noted "Query, an oval shaped spiral; major axis n-s."

300/350mm - 13.1" (3/24/84): faint, edge-on streak 4:1 NNW-SSE. Located 7.6' ESE of mag 7.3 SAO 81642 which interferes with viewing.

Notes by Steve Gottlieb