line under a moderately high sun. It is interesting to follow the
course of the principal cleft across the plain, and to note its progress
through the ridges and mountain groups it encounters. In the great Lick
telescope it is seen to traverse some old crater-rings which have not
been revealed in smaller instruments. About midway between Ariadaeus and
Silberschlag it exhibits a duplication for a short distance, first
detected by Webb.

DE MORGAN.--A brilliant little crater, 4 miles in diameter, on the plain
S. of the Ariadaeus cleft.

CAYLEY.--A very deep bright crater, with a dark interior, N. of the last,
and more than double its diameter. There is a second crater between this
and the cleft.

WHEWELL.--Another bright little ring, about 3 miles in diameter, some
distance to the E. of De Morgan and Cayley.

SOSIGENES.--A small circular ring-plain, 14 miles in diameter, with
narrow walls, a central mountain, and a minute crater outside the wall on
the E.; situated on the E. side of the Mare Tranquilitatis, W. of Julius
Caesar. There is another crater, about half its diameter, on the S.,
connected with it by a low mound. This has a still smaller crater on the
W. of it.

JULIUS CAESAR.--A large incomplete formation of irregular shape. The wall
on the E. is much terraced, and forms a flat "S" curve. The summit ridge
is especially bright, and has a conspicuous little crater upon it. On
the W. is a number of narrow longitudinal valleys trending from N. to S.,
included by a wide valley which constitutes the boundary on this side.
The border on the S. consists of a number of low rounded banks, those
immediately E. of Sosigenes being traversed by several shallow valleys,
which look as if they had been shaped by alluvial action. There is a
brilliant little hill at the end of one of these valleys, a few miles E.
of Sosigenes. The floor of Julius Caesar is uneven in tone, becoming
gradually duskier from S. to N., the northern end ranking among the
darkest areas on the lunar surface. There are at least three large
circular swellings in the interior. A long low mound, with two or three
depressions upon it, bounds the wide valley on the E. side.

GODIN.--A square-shaped ring-plain, 28 miles in diameter, with rounded
corners. The bright rampart is everywhere lofty, except on the S., is
much terraced, and includes a central mountain. On the S. a curious
trumpet-shaped valley, extending some distance towards the S.W., and
bounded