William Herschel discovered NGC 4236 = H V-51 = h1163 on 6 Apr 1793 (sweep 1036) and recorded "vF, mE, lbM, about 25' long, and losing itself imperceptibly, about 6 or 7' broad, from about 70° np to sf." His position, measured again on the next sweep, is accurate. John Herschel reported, "immensely large; vF; mE; vgbM; it fills more than a field, but is hardly distinguishable. Hazy." He incorrectly labeled his h1163 as H. V-17 in the Slough Catalogue.

300/350mm - 13.1" (5/27/84): faint, very large, very elongated NNW-SSE, weak concentration. In a field with five mag 8-9 stars.

400/500mm - 17.5" (3/29/89): faint, extremely large, edge-on 5:1 NNW-SSE. Appears as a ghostly streak about 20' length with only a broad, weak concentration! Best at low power due to size and low surface brightness.

Notes by Steve Gottlieb