hen changes its course as
abruptly to the N.W. again for 3 or 4 miles, once more turns to the S.W.,
and, as a much coarser chasm, maintains this direction for about 20
miles, till it reaches the S.E. edge of a great mountain plateau N. of
Aristarchus, when it swerves slightly towards the S., becoming wider and
wider, up to a place a few miles N. of Herodotus, where it expands into a
broad valley; and then, somewhat suddenly contracting in width, and
becoming less coarse, enters the ring-plain through a gap in the N. wall,
as before mentioned. I always find that portion of the valley in the
neighbourhood of Herodotus more or less indistinct, though it is broad
and deep. This part of it, unless it is observed at a late stage of
sunrise, is obscured by the shadow of the mountains on the border of the
plateau. Gruithuisen suspected a cleft crossing the region embraced by
the serpentine valley, forming a connection between its coarse southern
extremity and the long straight section. This has been often searched
for, but never found. It may exist, nevertheless, for in many instances
Gruithuisen's discoveries, though for a long time discredited, have been
confirmed. The mountain plateau N. of Aristarchus deserves careful
scrutiny, as it abounds in detail and includes many short clefts.

HARBINGER, MOUNTAINS.--A remarkable group of moderate height, mostly
extending from the N.W. towards Aristarchus. They include a large
incomplete walled-plain about 30 miles in diameter, defined on the W. by
a lofty border, forming part of a mountain chain, and open to the south.
This curious formation has many depressions in connection with its N.W.
edge. On the N. of it there is a crater-row and a very peculiar zig-zag
cleft. The region should be observed when the E. longitude of the morning
terminator is about 45 deg.

SCHIAPARELLI.--A conspicuous formation, about 16 miles in diameter,
between Herodotus and the N.E. limb, with a border rising nearly 2000
feet above the Mare, and about 1000 more above the floor, on which
Schmidt shows a central hill.

WOLLASTON.--A small bright crater on the Mare N. of the Harbinger
Mountains, surpassed in interest by a remarkable formation a few miles S.
of it, Wollaston B, an object of about the same size, but which is
associated with a much larger enclosure, resembling a walled-plain, lying
on the N. side of it. This formation has a lofty border on the W.,
surmounted by two small craters. The wall is low