"At this period," continued the learned Captain, "an atmosphere surrounded her. The waters, shut in by this gaseous envelope, could no longer evaporate. Under the combined influences of air, water, light, and solar heat as well as internal heat, vegetation began to overspread the continents by this time ready to receive it, and most undoubtedly--I mean--a--incontestably--it was at this epoch that _life_ manifested itself on the lunar surface. I say _incontestably_ advisedly, for Nature never exhausts herself in producing useless things, and therefore a world, so wonderfully inhabitable, _must_ of necessity have had inhabitants." "I like _of necessity_ too," said Ardan, who could never keep still; "I always did, when I felt my arguments to be what you call a little shaky." "But, my dear Captain," here observed Barbican, "have you taken into consideration some of the peculiarities of our Satellite which are decidedly opposed to the development of vegetable and animal existence? Those nights and days, for instance, 354 hours long?" "I have considered them all," answered the brave Captain. "Days and nights of such an enormous length would at the present time, I grant, give rise to variations in temperature altogether intolerable to any ordinary organization. But things were quite different in the era alluded to. At that time, the atmosphere enveloped the Moon in a gaseous mantle, and the vapors took the shape of clouds. By the screen thus formed by the hand of nature, the heat of the solar rays was tempered and the nocturnal radiation retarded. Light too, as well as heat, could be modified, tempered, and _genialized_ if I may use the expression, by the air. This produced a healthy counterpoise of forces, which, now that the atmosphere has completely disappeared, of course exists no longer. Besides--friend Ardan, you will excuse me for telling you something new, something that will surprise you--" --"Surprise me, my dear boy, fire away surprising me!" cried Ardan. "I like dearly to be surprised. All I regret is that you scientists have surprised me so much already that I shall never have a good, hearty, genuine surprise again!" --"I am most firmly convinced," continued the Captain, hardly waiting for Ardan to finish, "that, at the period of the Moon's occupancy by living creatures, her days and nights were by no means 354 hours long." "Well! if anything could surprise me," said Ardan quickly, "such an assertion as that most certainly would. On what does the honorable gentleman base his _most firm conviction_?"