On Rukl's chart 36, Rima and Rupes Cauchy make a striking pair of
parallel slashes flanking their namesake crater in Mare Tranquilitatus;
and in the photo appendix he shows a photo of this area, equally striking.
I tried for many months to get a glimpse of the "hyperbolas".
At 4/15/98 12:30am PDT, with the area in sunset and the terminator
passing through the prominent Macrobius, Rupes Cauchy stood out as a
bright line (just as Rukl says: it casts a shadow at sunrise, but appears
bright at sunset), but I was unable to see any trace of Rima Cauchy.
Finally, on 3/21/99 at 7:30pm PST, I got a good view of both of them.
The rille was still quite a bit less prominent than the wall, but the
pair was eyecatching and obvious in a 6" Newtonian.
The strong impression they give is that the area between the hyperbolas
is a plateau, raised compared to the area outside; I was unable to shake
this impression although I don't believe it to be true.