"What for?" asked Nicholl.
"In order to preserve themselves from the ardour of the solar rays, which strike the moon during fifteen consecutive days."
"The Selenites were not fools!" said Michel.
"It was a singular idea!" answered Nicholl. "But it is probable that Kepler did not know the real dimensions of these circles, for digging them would have been giants' labour, impracticable for Selenites."
"Why so, if the weight on the surface of the moon is six times less than upon the surface of the earth?" said Michel.
"But if the Selenites are six times smaller?" replied Nicholl.
"And if there are no Selenites?" added Barbicane, which terminated the discussion.
Eratosthenes soon disappeared from the horizon without the projectile having been sufficiently near it to allow a rigorous observation. This mountain separated the Apennines from the Carpathians.
In lunar orography, several chains of mountains have been distinguished which are principally distributed over the northern hemisphere. Some, however, occupy certain portions of the southern hemisphere.
The following is a list of these different chains, with their latitudes and the height of their highest summits:—