but
continuous border, except on the S., where two large ring-plains have
encroached upon it, and a third, N. of a line joining their centres,
occupies no inconsiderable portion of the floor. Heinsius is nearly 50
miles across, and the border on the W., is nearly 9000 feet above the
interior, which includes, at least, three small craters. The walls of the
intrusive ring-plains have craters on their summits; the more westerly
has two on the W., and its companion, one on the S.W. The ring-plain on
the floor has a crater on its E. wall. Schmidt shows a small crater
between the ring-plains on the S. border.

SAUSSURE.--A ring-plain W. of Tycho, 28 miles in diameter, with bright
lofty terraced walls and a somewhat dark interior, on which there is a
crater, W. of the centre, and some crater-pits. There are several large
depressions on the S.W. wall. It is surrounded by formations which,
though nearly as prominent as itself, have not, with the exception of
Pictet on the E., and one on the N.W., called Huggins by Schmidt,
received distinctive names. The region W. of Saussure abounds in
craterlets, some of which are of the minutest type. One of the Tycho
streaks is manifestly deflected from its course by this formation, and
another is faintly traceable on the floor.

PICTET.--A walled-plain of irregular shape, about 30 miles across,
between Saussure and Tycho, with a border broken on the S. by a large
conspicuous ring-plain, which is at least 10 miles in diameter, and,
according to Schmidt, has a central mountain. Schmidt draws the S.E.
border of Pictet as broken by ridges extending on to the floor. He also
shows several craters and minor elevations thereon.

TYCHO.--As the centre from which the principal bright ray-system of the
moon radiates, and the most conspicuous object in the southern
hemisphere, this noble ring-plain may justly claim the pre-eminent title
of "the Metropolitan crater." It is more than 54 miles in diameter, and
its massive border, everywhere traversed by terraces and variegated by
depressions within and without, is surmounted by peaks rising both on the
E. and W. to a height of about 17,000 feet above the bright interior, on
which stands a magnificent central mountain at least 5000 feet in
altitude. Were it not somewhat foreshortened, Tycho would be seen to
deviate considerably from what is deemed to be the normal shape. On the
S. and W. especially, the wall approximates to the linear type, no signs
of