THE MOOH. 
613 
in which the flat floor is dotted with numerous pits or covered 
with broken fragments of rock. Occasionally a regularly- 
formed and unusually symmetrical circular formation makes 
its appearance ; the exterior surface of the wall bristling 
with terraces rising gradually from the plane_, the interior one 
much more steep_, and instead of a flat floor^, the inner space 
is concave or cup-shaped, with a solitary peak rising in the 
centre. Solitary peaks rise from the level plains and cast 
then* long", narrow shadows athwart the smooth surface ; their 
great heightds seen from the distance between the summit, 
when first illuminated by the sunlight, and the illuminated 
continent. Vast planes of a dusky tint, which were long 
mistaken for seas, become visible, but it will be seen that 
they are not perfectly level, but covered with ripples, pits, 
and projections. Circular wells, in which there is no sur- 
rounding wall, dip below the plain, and are met with even in 
the interior of the circular mountains and on the tops of its 
walls. From some of the mountains great streams of a 
brilliant white radiate in all directions, and can be traced for 
hundreds of miles. We see, again, great fissures, almost 
perfectly straight and of great length, although very narrow, 
which appear like the cracks in moist clayey soil when dried 
by the sun. This heap of fissures, cWerns, plains, bright 
radiations, “ ring mountains (whether cup-shaped or with 
flat floors), great chains of immense height, fearful Matter- 
horns, and solitary peaks, are scattered in the greatest dis- 
order, and met with at every phase of the moon. There is 
no sign of life or motion — no clouds floating over the lunar 
surface, and the latter might be mistaken for the locality 
between Dan and Beersheba. 
The so-called seas are of immense size, and indeed the 
only separate formations which can be seen with the naked 
eye, when they appear - as dusky spots. They are mostly of 
a circular shape, and on this account are supposed to have 
some connection with the other annular formations of the 
moon. Twenty-one of those have been counted, which have 
received, among others, the fanciful appellations of the Seas 
of Clouds, Fertility, Sleep, Dreams, &c. The Mare Serenitatlsj 
situated in the north-western part of the moon, is one of the 
largest, and is connected with the other great plains, the 
Mare TranquilUtatis and the Mare Foecunditatis , the three being- 
in nearly a straight line, and occupying a very considerable 
portion of the western part of the moon. It is calculated that 
the surface of the Mare Serenitatis is about the area of the 
British islands, and its diameter between four and five 
hundred miles. The Oceanus Frocellarum, in the opposite 
quadrant, is that which is most apparent when the moon is 
