t shows, but far too prominently,
two straight ridges crossing each other on the S. side of the central
crater.

CASATUS.--A large walled-plain, about 50 miles in diameter, S.E. of
Blancanus, near the limb, remarkable for having one of the loftiest
ramparts of all known lunar objects; it rises at one peak on the S.W. to
the great height of 22,285 feet above the floor, while there are other
peaks nearly as high on the N. and S. The wall is broken on the E. by a
fine crater. There is also a crater on the N.W. side of the very
depressed floor, together with some craterlets.

KLAPROTH.--Casatus partially overlaps this still larger but less massive
formation on its S.E. flank. The walls of Klaproth are much lower and
very irregular and broken, especially on the W. There are some ridges on
the floor. The neighbouring region is covered with unnamed objects, large
and small.

EAST LONGITUDE 40 deg. TO 60 deg.

FLAMSTEED.--A bright ring-plain, 9 miles in diameter, in a barren region
in the Oceanus Procellarum, N.E. of Wichmann. It has a regular border
(broken at one place on the N. by a gap, which probably represents a
crater), rising to a height of about 1400 feet above the surrounding
plain. A great enclosure, 60 miles in diameter, lies on the N. of
Flamsteed. It is defined by low ridges which exhibit many breaks, though
under a high light the ring is apparently continuous. Within are several
small craters and two considerable hills, nearly central.

HERMANN.--A ring-plain, about 10 miles in diameter, in the Oceanus
Procellarum, W. of Lohrmann. It is associated with a group of long
ridges, running in a meridional direction and roughly parallel to the
coast-line.

LETRONNE.--A magnificent bay or inflexion in the coast-line of the
Oceanus Procellarum, N.N.E. of Gassendi, presenting an opening towards
the N. of nearly 50 miles, and bounded on the S. and S.W. by the lofty
Gassendi highlands. Its border on the W., about 3000 feet high, is
crowned with innumerable small depressions. The interior includes four
bright little mountains, nearly central (three of them forming a
triangle), a bright crater on the W. side, and several minor elevations
and ridges. On the plain N. of the bay, is a large bright crater, from
which a fine curved ridge runs to the central mountains. If Letronne is
observed under oblique illumination, the low mounds and ridges on the
Mare outside impress one with the idea that they represent the remain