osed the
"Sea" on its northern boundary. Here a radiating mountain showed a
summit so dazzling with the reflection of the solar rays that Ardan
could not help crying out:

"It looks like one of the carbon points of an electric light projected
on a screen! What do you call it, Barbican?"

"_Copernicus_," replied the President. "Let us examine old
_Copernicus_!"

This grand crater is deservedly considered one of the greatest of the
lunar wonders. It lifts its giant ramparts to upwards of 12,000 feet
above the level of the lunar surface. Being quite visible from the Earth
and well situated for observation, it is a favorite object for
astronomical study; this is particularly the case during the phase
existing between Last Quarter and the New Moon, when its vast shadows,
projected boldly from the east towards the west, allow its prodigious
dimensions to be measured.

After _Tycho_, which is situated in the southern hemisphere,
_Copernicus_ forms the most important radiating mountain in the lunar
disc. It looms up, single and isolated, like a gigantic light-house, on
the peninsula separating _Mare Nubium_ from _Oceanus Procellarum_ on one
side and from _Mare Imbrium_ on the other; thus illuminating with its
splendid radiation three "Seas" at a time. The wonderful complexity of
its bright streaks diverging on all sides from its centre presented a
scene alike splendid and unique. These streaks, the travellers thought,
could be traced further north than in any other direction: they fancied
they could detect them even in the _Mare Imbrium_, but this of course
might be owing to the point from which they made their observations. At
one o'clock in the morning, the Projectile, flying through space, was
exactly over this magnificent mountain.

In spite of the brilliant sunlight that was blazing around them, the
travellers could easily recognize the peculiar features of _Copernicus_.
It belongs to those ring mountains of the first class called Circuses.
Like _Kepler_ and _Aristarchus_, who rule over _Oceanus Procellarum_,
_Copernicus_, when viewed through our telescopes, sometimes glistens so
brightly through the ashy light of the Moon that it has been frequently
taken for a volcano in full activity. Whatever it may have been once,
however, it is certainly nothing more now than, like all the other
mountains on the visible side of the Moon, an extinct volcano, only with
a crater of such exceeding grandeur and sublimity as to throw