What was this radiating aureole?  What geological phenomenon had caused those ardent beams?  This question justly occupied Barbicane.  Under his eyes, in every direction, ran luminous furrows, with raised banks and concave middle, some ten miles, others more than twenty miles wide.  These shining trails ran in certain places at least 300 leagues from Tycho, and seemed to cover, especially towards the east, north-east, and north, half the southern hemisphere.  One of these furrows stretched as far as the amphitheatre of Neander, situated on the 40th meridian.  Another went rounding off through the Sea of Nectar and broke against the chain of the Pyrenees after a run of 400 leagues; others towards the west covered with a luminous network the Sea of Clouds and the Sea of Humours.

What was the origin of these shining rays running equally over plains and reliefs, however high?  They all started from a common centre, the crater of Tycho.  They emanated from it.

Herschel attributed their brilliant aspect to ancient streams of lava congealed by the cold, an opinion which has not been generally received.  Other astronomers have seen in these inexplicable rays a kind of moraines, ranges of erratic blocks thrown out at the epoch of the formation of Tycho.

“And why should it not be so?” asked Nicholl of Barbicane, who rejected these different opinions at the same time that he related them.

“Because the regularity of these luminous lines, and the violence necessary to send them to such a distance, are inexplicable.

“Par bleu!” replied Michel Ardan.  “I can easily explain to myself the origin of these rays.”

“Indeed,” said Barbicane.

“Yes,” resumed Michel.  “Why should they not be the cracks caused by the shock of a bullet or a stone upon a pane of glass?”

“Good,” replied Barbicane, smiling; “and what hand would be powerful enough to hurl the stone that would produce such a shock?”

“A hand is not necessary,” answered Michel, who would not give in; “and as to the stone, let us say it is a comet.”

“Ah! comets?” exclaimed Barbicane; “those much-abused comets!  My worthy Michel, your explanation is not bad, but your comet is not wanted.  The shock might have come from the interior of the planet.  A violent contraction of the lunar crust whilst cooling was enough to make that gigantic crack.”

“Contraction let it be—­something like a lunar colic,” answered Michel Ardan.

“Besides,” added Barbicane, “that is also the opinion of an English savant, Nasmyth, and it seems to me to explain the radiation of these mountains sufficiently.”

“That Nasmyth was no fool!” answered Michel.

The travellers, who could never weary of such a spectacle, long admired the splendours of Tycho.  Their projectile, bathed in that double irradiation of the sun and moon, must have appeared like a globe of fire.  They had, therefore, suddenly passed from considerable cold to intense heat.  Nature was thus preparing them to become Selenites.