"On again, then," replied Ardan; "Herschel, in 1787, observed a great number of luminous points on the moon's surface, did he not?" "Yes! but without offering any solution of them. Herschel himself never inferred from them the necessity of a lunar atmosphere. And I may add that Bœer and Moedler, the two great authorities upon the moon, are quite agreed as to the entire absence of air on its surface." A movement was here manifest among the assemblage, who appeared to be growing excited by the arguments of this singular personage. "Let us proceed," replied Ardan, with perfect coolness, "and come to one important fact. A skilful French astronomer, M. Laussedat, in watching the eclipse of July 18, 1860, proved that the horns of the solar crescent were _rounded and truncated._ Now, this appearance could only have been produced by a deviation of the solar rays in traversing the atmosphere of the moon. There is no other possible explanation of the fact." "But is this established as a fact?" "Absolutely certain!" A counter-movement here took place in favour of the hero of the meeting, whose opponent was now reduced to silence. Ardan resumed the conversation; and without exhibiting any exultation at the advantage he had gained, simply said,— "You see, then, my dear sir, we must not pronounce with absolute positiveness against the existence of an atmosphere in the moon. That atmosphere is, probably, of extreme rarity; nevertheless at the present day science generally admits that it exists." "Not in the mountains, at all events," returned the unknown, unwilling to give in. "No! but at the bottom of the valleys, and not exceeding a few hundred feet in height." "In any case you will do well to take every precaution, for the air will be terribly rarified." "My good sir, there will always be enough for a solitary individual; besides, once arrived up there, I shall do my best to economize, and not to breathe except on grand occasions!" A tremendous roar of laughter rang in the ears of the mysterious interlocutor, who glared fiercely round upon the assembly. "Then," continued Ardan, with a careless air, "since we are in accord regarding the presence of a certain atmosphere, we are forced to admit the presence of a certain quantity of water. This is a happy consequence for me. Moreover, my amiable contradictor, permit me to submit to you one further observation. We only know one side of the moon's disc; and if there is but little air on the face presented to us, it is possible that there is plenty on the one turned away from us." "And for what reason?" "Because the moon, under the action of the earth's attraction, has assumed the form of an egg, which we look at from the smaller end. Hence it follows, by Hausen's calculations, that its centre of gravity is situated in the other hemisphere. Hence it results that the great mass of air and water must have been drawn away to the other face of our satellite during the first days of its creation."