The time went by in interminable conversations.  The talk was especially about the moon.  Each brought his contingent of particular knowledge.  Barbicane’s and Nicholl’s were always serious, Michel Ardan’s always fanciful.  The projectile, its situation and direction, the incidents that might arise, the precautions necessitated by its fall upon the moon, all this afforded inexhaustible material for conjecture.

Whilst breakfasting a question of Michel’s relative to the projectile provoked a rather curious answer from Barbicane, and one worthy of being recorded.

Michel, supposing the bullet to be suddenly stopped whilst still endowed with its formidable initial velocity, wished to know what the consequences would have been.

“But,” answered Barbicane, “I don’t see how the projectile could have been stopped.”

“But let us suppose it,” answered Nicholl.

“It is an impossible supposition,” replied the practical president, “unless the force of impulsion had failed.  But in that case its speed would have gradually decreased, and would not have stopped abruptly.”

“Admit that it had struck against some body in space.”

“What body?”

“The enormous meteor we met.”

“Then,” said Nicholl, “the projectile would have been broken into a thousand pieces, and we with it.”

“More than that,” answered Barbicane, “we should have been burnt alive.”

“Burnt!” exclaimed Michel.  “I regret it did not happen for us just to see.”

“And you would have seen with a vengeance,” answered Barbicane.  “It is now known that heat is only a modification of movement when water is heated—­that is to say, when heat is added to it—­that means the giving of movement to its particles.”

“That is an ingenious theory!” said Michel.

“And a correct one, my worthy friend, for it explains all the phenomena of caloric.  Heat is only molecular movement, a single oscillation of the particles of a body.  When the break is put on a train it stops.  But what becomes of the movement which animated it?  Why do they grease the axles of the wheels?  In order to prevent them catching fire from the movement lost by transformation.  Do you understand?”

“Admirably,” answered Michel.  “For example, when I have been running some time, and am covered with sweat, why am I forced to stop?  Simply because my movement has been transformed into heat.”

Barbicane could not help laughing at this repartie of Michel’s.  Then resuming his theory—­

“Thus,” said he, “in case of a collision, it would have happened to our projectile as it does to the metal cannon-ball after striking armour-plate; it would fall burning, because its movement had been transformed into heat.  In consequence, I affirm that if our bullet had struck against the asteroid, its speed, suddenly annihilated, would have produced heat enough to turn it immediately into vapour.”