"Straight as an arrow!" added Ardan.
"Running through lofty mountains!" cried M'Nicholl.
"Cut through with a pair of saws and scooped out with a chisel!" cried Ardan.
"See the shadows of those peaks!" cried M'Nicholl catching fire at the sight. "Black, long, and sharp as if cast by cathedral spires!"
"Oh! ye crags and peaks!" burst forth Ardan; "how I should like to catch even a faint echo of the chorus you could chant, if a wild storm roared over your beetling summits! The pine forests of Norwegian mountains howling in midwinter would not be an accordeon in comparison!"
"Wonderful instance of subsidence on a grand scale!" exclaimed the Captain, hastily relapsing into science.
"Not at all!" cried the Frenchman, still true to his colors; "no subsidence there! A comet simply came too close and left its mark as it flew past."
"Fanciful exclamations, dear friends," observed Barbican; "but I'm not surprised at your excitement. Yonder is the famous Valley of the Alps, a standing enigma to all selenographers. How it could have been formed, no one can tell. Even wilder guesses than yours, Ardan, have been hazarded on the subject. All we can state positively at present regarding this wonderful formation, is what I have just recorded in my note-book: the Valley of the Alps is about 5 mile wide and 70 or 80 long: it is remarkably flat and free from debris, though the mountains on each side rise like walls to the height of at least 10,000 feet.—Over the whole surface of our Earth I know of no natural phenomenon that can be at all compared with it."
"Another wonder almost in front of us!" cried Ardan. "I see a vast lake black as pitch and round as a crater; it is surrounded by such lofty mountains that their shadows reach clear across, rendering the interior quite invisible!"
"That's Plato;" said M'Nicholl; "I know it well; it's the darkest spot on the Moon: many a night I gazed at it from my little observatory in Broad Street, Philadelphia."