FOUCAULT.—­A bright deep ring-plain, about 10 miles in diameter, lying E. of the mountains fringing the Sinus Iridum, between Bianchini and Harpalus.  A very lofty peak rises near its N. border, and, according to Neison, it has a distinct central mountain, though neither Madler or Schmidt show any detail within.

HARPALUS.—­A conspicuous ring-plain, about 14 miles in diameter, on the N.E. of the last, with a floor sinking 13,000 feet below the surrounding surface.  As the cubic contents of the border and glacis are quite inadequate to account for it, we may ask, what has become of the material which presumably once filled this vast depression?  Harpalus has a bright central mountain.

SOUTH.—­On the W. and S., the boundaries of this extensive enclosure are merely indicated by ridges, which nowhere attain the dignity of a wall.  On the N., the edge of a tableland intersected by a number of valleys define its limits, and on the E. a border forming also the W. side of Babbage.  The interior is traversed by a number of longitudinal hills, and includes two bright little heights, drawn by Schmidt as craters.

BABBAGE.—­A still larger enclosed area, adjoining South on the E., and containing a considerable ring-plain near its W. border.  It is a fine telescopic object at sunrise, the interior being crossed by a number of transverse markings representing ridges.  These are very similar in character (but much coarser) to those found on the floor of J.F.W.  Herschel.  The curious detail on the E. wall is also worth examination at this phase.

ROBINSON.—­A bright and very deep little ring-plain, about 12 miles in diameter, on a plateau N. of South.  Schmidt shows a crater on the W. border, and two others at the foot of the N. and E. borders respectively.

ANAXIMANDER.—­A fine but much foreshortened ring-plain, 39 miles in diameter, abutting on the E. side of J.F.W.  Herschel.  It has a large crater on its W. border, which is common to the two formations, and a very prominent crater, both on the S. and N. The barrier on the S.W. rises to a height of nearly 10,000 feet.  Schmidt shows a crater and other details on the floor.

EAST LONGITUDE 60 deg.  TO 90 deg.

LOHRMANN.—­This ring-plain, with Hevel and Cavalerius on the N. of it, is a member of a linear group, which, but for its propinquity to the limb, would be one of the most imposing on the moon’s surface.  Lohrmann, about 28 miles in diameter, is surrounded by a bright wall, which, to all appearance, is devoid of detail.  Two prominent ridges, with a fine intervening valley, connect it with the N. end of Grimaldi.  It has a large but not conspicuous central mountain.  On the rugged surface, between the ring-plain and the E. edge of the Oceanus Procellarum, lies a very interesting group of crossed clefts, some of which run from N.E. to S.W., and others from N.W. to S.E.  Three of the latter proceed from different points in a coarse valley extending from W. to E.,