I recorded it once nearly 30 years ago with a 17.5-inch in the California Sierras (elevation 7050 ft):
“Extremely faint, very small, round, low even surface brightness. A mag 14 star is 1′ SE. Located 5′ WSW of two mag 10/11.5 stars.”
William’s Herschel’s description is interesting (his 18.7-inch speculum reflector, equivalent with at most a modern 15-inch):
“Extremely faint, 240x left a doubt, though it rather confirmed it. I perceived it in counting a field, otherwise I should never have suspected it.” “Counting a field” refers to taking a star count or “star gauge” of the eyepiece field. He performed these all over the sky.
