It seems I've been taken in by all this lunacy!

Better seeing tonight, for a brief period before some high clouds rolled in. The clouds are thin, and the moon is quite visible through them, but they have stirred up the air (or perhaps they are symptoms of stirred up air?) and now it's hard to see any fine detail. For 30 min or so between setup and cloud arrival, I was able to observe at around 200x to good effect.

I revisited J. Herschel, to see how it appeared under different lighting conditions. The dark valley reaching towards Anaximander, which yesterday I had taken to be a shadow effect, actually seems to exist! I see it as a neat cleft in the wall of J. Herschel, with the valley extending directly away from the center of that crater. It may end before the Anaximander ring-wall; I did not see a clear break there as I did at the Herschel end. There is no sign that the valley extends onto the floor of Herschel. The floor of the valley appears darker than the surrounding material. Wilkins (in _The Moon_, with Patrick Moore, 1961) drew a small crater on the wall of J. Herschel near the position of this "cleft"; perhaps that's what I'm seeing. In any case with 70mm this area appears to me very different than as mapped by Rukl(map 2).

Next I turned to Mons Rumker (Rukl 8), one of my favorite lunar sights - though it appears more interesting with larger scopes. Tonight all I was able to make out was a general lumpiness, and a pronounced dark spot southwest of center. With Rumker close to the terminator, I took this spot to be a low-rimmed, shadow filled crater at the limit of my resolution. But looking now in Rukl, I see he draws it as an indefinite, dark spot with no walls at all. Any other impressions of this feature?

Moving southward along the shores of Procellarum, just being touched by the lunar sunrise, I came Damoiseau (Rukl 39). This appears as an interesting set of concentric craters, almost like a bullseye. The rings are so neatly arranged that I doubt they could have been created by successive impacts. More likely the appearance is caused by an unusual circumstance of collapse or erosion of a single crater wall.

Nearby is the double crater Sirsalis. (Wilkins and Moore identify the westerly of these twins as Bertaud, but it seems that name didn't stick.) Rukl draws the westerly component (which he calls "A") as the lower and less defined of the two. Wilkins and Moore agree, putting the height of Sirsalis' walls at up to 10,000 feet and those of Bertaud (Rukl's "A") at only 3000 feet. Yet under observation near the terminator, Bertaud ("A") seems the more filled with light even in its more westerly position. My guess at an explanation is that Sirsalis' wall is much higher on the eastern side than the west. The high eastern wall blocks sunlight, keeping the crater floor and the inside slope of the western wall in shadow. The lower western wall of Sirsalis neither rises to catch the sunlight, nor casts much of a shadow upon Bertaud. Sound reasonable?

Signing off for a couple of days...clear skies to you all!