e
right and the western hemisphere on the left. It is the moon's western
edge that catches the first sunlight when "new moon" begins, and, as the
phase increases, passing into "first quarter" and from that to "full
moon," the illumination sweeps across the disk from west to east.

[Illustration: LUNAR CHART NO. 1, NORTHWEST QUARTER.]

The narrow sickle of the new moon, hanging above the sunset, is a
charming telescopic sight. Use a low power, and observe the contrast
between the bright, smooth round of the sunward edge, which has almost
the polish of a golden rim, and the irregular and delicately shaded
inner curve, where the adjacent mountains and plains picturesquely
reflect or subdue the sunshine. While the crescent grows broader new
objects are continually coming into view as the sun rises upon them,
until at length one of the most conspicuous and remarkable of the lunar
"seas," the _Mare Crisium_, or Sea of Crises, lies fully displayed amid
its encircling peaks, precipices, and craters. The _Mare Crisium_ is all
in the sunlight between the third and fourth day after "new moon." It is
about 350 by 280 miles in extent, and if ever filled with water must
have been a very deep sea, since its arid bed lies at a great but not
precisely ascertained depth below the general level of the moon. There
are a few small craters on the floor of the _Mare Crisium_, the largest
bearing the name of Picard, and its borders are rugged with mountains.
On the southwestern side is a lofty promontory, 11,000 feet in height,
called Cape Agarum. At the middle of the eastern side a kind of bay
opens deep in the mountains, whose range here becomes very narrow.
Southeast of this bay lies a conspicuous bright point, the crater
mountain Proclus, on which the sun has fully risen in the fourth day of
the moon, and which reflects the light with extraordinary liveliness.
Adjoining Proclus on the east and south is a curious, lozenge-shaped
flat, broken with short, low ridges, and possessing a most peculiar
light-brown tint, easily distinguished from the general color tone of
the lunar landscapes. It would be interesting to know what was passing
in the mind of the old astronomer who named this singular region _Palus
Somnii_. It is not the only spot on the moon which has been called a
"marsh," and to which an unexplained connection with dreams has been
ascribed.

Nearly on the same meridian with Proclus, at a distance of about a
hundred miles northwa