“What are we looking at now?” asked Michel.

“At the northern portion of the Sea of Clouds,” answered Barbicane.  “We are too far off to make out its nature.  Are those plains composed of dry sand, as the first astronomers believed?  Or are they only immense forests, according to the opinion of Mr. Waren de la Rue, who grants a very low but very dense atmosphere to the moon?  We shall find that out later on.  We will affirm nothing till we are quite certain.”

“This Sea of Clouds is rather doubtfully traced upon the maps.  It is supposed that this vast plain is strewn with blocks of lava vomited by the neighbouring volcanoes on its right side, Ptolemy, Purbach, and Arzachel.  The projectile was drawing sensibly nearer, and the summits which close in this sea on the north were distinctly visible.  In front rose a mountain shining gloriously, the top of which seemed drowned in the solar rays.”

“That mountain is—?” asked Michel.

“Copernicus,” answered Barbicane.

“Let us have a look at Copernicus,” said Michel.

This mountain, situated in north latitude 9 deg., and east longitude 20 deg., rises to a height of nearly 11,000 feet above the surface of the moon.  It is quite visible from the earth, and astronomers can study it with ease, especially during the phase between the last quarter and the new moon, because then shadows are thrown lengthways from east to west, and allow the altitudes to be taken.

Copernicus forms the most important radiating system in the southern hemisphere, according to Tycho Brahe.  It rises isolated like a gigantic lighthouse over that of the Sea of Clouds bordering on the Sea of Tempests, and it lights two oceans at once with its splendid rays.  Those long luminous trails, so dazzling at full moon, made a spectacle without an equal; they pass the boundary chains on the north, and stretch as far as the Sea of Rains.  At 1 a.m., terrestrial time, the projectile, like a balloon carried into space, hung over this superb mountain.

Barbicane could perfectly distinguish its chief features.  Copernicus is comprehended in the series of annular mountains of the first order in the division of the large amphitheatres.  Like the mountains of Kepler and Aristarchus, which overlook the Ocean of Tempests, it appears sometimes like a brilliant point through the pale light, and used to be taken for a volcano in activity.  But it is only an extinct volcano, like those on that side of the moon.  Its circumference presented a diameter of about twenty-two leagues.  The glasses showed traces of stratifications in it produced by successive eruptions, and its neighbourhood appeared strewn with volcanic remains, which were still seen in the crater.