umber of
little craters and very low longitudinal mounds. Ten craters are shown in
Beer and Madler's map. Schmidt only draws fifteen, though in the text
accompanying his chart he says that he once counted fifty. In the
monograph published in the _Journal_ of the Liverpool Astronomical
Society (vol. v. part 8), forty-one are represented. They appear to be
rather more numerous on the S. half of the floor than elsewhere. Just
beyond the limits of the border on the N., is a bright crater with a much
larger obscure depression on the W. of it. The former is surrounded by a
multitude of minute craters and crater-cones, which are easily seen under
a low sun. Though almost every trace of Stadius disappears under a high
light, I have had little difficulty in seeing portions of the border and
some of the included details when the morning terminator had advanced as
far as the E. wall of Herodotus, and the site was traversed by
innumerable light streaks radiating from Copernicus. At this phase the
bright crater, just mentioned, on the N. edge of the border was tolerably
distinct.

COPERNICUS.--This is without question the grandest object, not only on
the second Quadrant, but on the whole visible superficies of the moon. It
undoubtedly owes its supremacy partly to its comparative isolation on the
surface of a vast plain, where there are no neighbouring formations to
vie with it in size and magnificence, but partly also to its favourable
position, which is such, that, though not central, is sufficiently
removed from the limb to allow all its manifold details to be critically
examined without much foreshortening. There are some other formations,
Langrenus and Petavius, for example, which, if they were equally well
situated, would probably be fully as striking; but, as we see it
Copernicus is _par excellence_ the monarch of the lunar ring-mountains.
Schmidt remarks that this incomparable object combines nearly all the
characteristics of the other ring-plains, and that careful study directed
to its unequalled beauties and magnificent form is of much more value
than that devoted to a hundred other objects of the same class. It is
fully 56 miles in diameter, and, though generally described as nearly
circular, exhibits very distinctly under high powers a polygonal outline,
approximating very closely to an equilateral hexagon. There are, however,
two sections of the crest of the border on the N.E. which are inflected
slightly towards the cen