fficult to detect under a high sun, Madler's dictum that "the full
moon knows no Maginus" is not strictly true.

STREET.--A walled-plain between Tycho and Maginus, about 28 miles in
diameter, with a border of moderate height, broken by depressions on the
N. There are some small craters and ridges within; but the surrounding
region, with its almost endless variety of abnormally shaped formations,
is far more worthy of the observer's attention.

DELUC.--The largest and most prominent member of a curious group of ring-
plains on the S.W. of Maginus. It is about 28 miles in diameter, and is
encircled by a wall some 7000 feet above the interior, which includes a
crater. A large ring with a central mountain encroaches on the N. wall,
and a smaller object of the same class on the S. wall.

CLAVIUS.--There are few lunar observers who have not devoted more or less
attention to this beautiful formation, one of the most striking of
telescopic objects. However familiar we may consider ourselves to be with
its features, there is always something fresh to note and to admire as
often as we examine its apparently inexhaustible details. It is 142 miles
from side to side, and includes an area of at least 16,000 square miles
within its irregular circumvallation, which is only comparatively
slightly elevated above the bright plateau on the W., though it stands at
least 12,000 feet above the depressed floor. At a point on the S.W. a
peak rises nearly 17,000 feet above the interior, while on the E. the
cliffs are almost as lofty. There are two remarkable ring-plains, each
about 25 miles in diameter, associated, one with the N., and the other
with the S. wall, the floors of both abounding in detail. The latter,
however, is the most noteworthy on account of the curious corrugations
visible soon after sunrise on the outer N. slope of its wall, resembling
the ribbed flanks of some of the Java volcanoes. There are five large
craters on the floor of Clavius, following a curve convex to the N., and
diminishing in size from W. to E. The most westerly stands nearly midway
between the two large ring-plains on the walls, the second (about two-
thirds its area) is associated with a complex group of hills and smaller
craters. Both these objects have central mountains. In addition to this
prominent chain, there are innumerable craters of a smaller type on the
floor, but they are more plentiful on the S. half than elsewhere. On the
S.E. wall are three ver