little ringed one called Guy Lussac, the breadth of which
measured twelve miles.
Toward the south, the plain was very flat, without one
elevation, without one projection. Toward the north, on the
contrary, till where it was bounded by the “Sea of Storms,” it
resembled a liquid surface agitated by a storm, of which the
hills and hollows formed a succession of waves suddenly congealed.
Over the whole of this, and in all directions, lay the luminous
lines, all converging to the summit of Copernicus.
The travelers discussed the origin of these strange rays; but they
could not determine their nature any more than terrestrial observers.
“But why,” said Nicholl, “should not these rays be simply spurs
of mountains which reflect more vividly the light of the sun?”
“No,” replied Barbicane; “if it was so, under certain conditions
of the moon, these ridges would cast shadows, and they do not
cast any.”
And indeed, these rays only appeared when the orb of day was in
opposition to the moon, and disappeared as soon as its rays
became oblique.
“But how have they endeavored to explain these lines of light?”
asked Michel; “for I cannot believe that savants would ever be
stranded for want of an explanation.”
“Yes,” replied Barbicane; “Herschel has put forward an opinion,
but he did not venture to affirm it.”
“Never mind. What was the opinion?”
“He thought that these rays might be streams of cooled lava
which shone when the sun beat straight upon them. It may be so;
but nothing can be less certain. Besides, if we pass nearer to
Tycho, we shall be in a better position to find out the cause of
this radiation.”
“Do you know, my friends, what that plain, seen from the height
we are at, resembles?” said Michel.
“No,” replied Nicholl.
“Very well; with all those pieces of lava lengthened like rockets,
it resembles an immense game of spelikans thrown pellmell.
There wants but the hook to pull them out one by one.”
“Do be serious,” said Barbicane.
“Well, let us be serious,” replied Michel quietly; “and instead
of spelikans, let us put bones. This plain, would then be
nothing but an immense cemetery, on which would repose the
mortal remains of thousands of extinct generations. Do you
prefer that high-flown comparison?”
“One is as good as the other,” retorted Barbicane.
“My word, you are difficult to please,” answered Michel.
“My worthy friend,” continued the matter-of-fact Barbicane, “it
matters but little what it _resembles_, when we do not know what
it _is_.”
“Well answered,” exclaimed Michel. “That will teach me to
reason with savants.”
But the projectile continued to advance with almost uniform
speed around the lunar disc. The travelers, we may easily
imagine, did not dream of taking a moment’s rest. Every minute
changed the landscape which fled from beneath their gaze.
About half past one o’clock in the morning, they caught a glimpse
of the tops of another mountain. Barbicane, consulting his map,
recognized Eratosthenes.
It was a ringed mountain nine thousand feet high, and one of
those circles so numerous on this satellite. With regard to
this, Barbicane related Kepler’s singular opinion on the
formation of circles. According to that celebrated
mathematician, these crater-like cavities had been dug by the
hand of man.
“For what purpose?” asked Nicholl.
“For a very natural one,” replied Barbicane. “The Selenites
might have undertaken these immense works and dug these enormous
holes for a refuge and shield from the solar rays which beat
upon them during fifteen consecutive days.”
“The Selenites are not fools,” said Michel.
“A singular idea,” replied Nicholl; “but it is probable that
Kepler did not know the true dimensions of these circles, for
the digging of them would have been the work of giants quite
impossible for the Selenites.”
“Why? if weight on the moon’s surface is six times less than on
the earth?” said Michel.
“But if the Selenites are six times smaller?” retorted Nicholl.
“And if there are _no_ Selenites?” added Barbicane.
This put an end to the discussion.
Soon Eratosthenes disappeared under the horizon without the
projectile being sufficiently near to allow close observation.
This mountain separated the Apennines from the Carpathians. In the