“A fine sentence,” said Michel Ardan; “rather academical perhaps.”
“It follows,” resumed Barbicane, nowise put out, “that the visible face of the disc must be very agreeable to inhabit, as it is always lighted by the sun or the moon.”
“But,” said Nicholl, “this advantage must be quite compensated by the unbearable heat which this light must cause.”
“This inconvenience is the same under two faces, for the light reflected by the earth is evidently deprived of heat. However, this invisible face is still more deprived of heat than the visible face. I say that for you, Nicholl; Michel would probably not understand.”
“Thank you,” said Michel.
“In fact,” resumed Barbicane, “when the invisible face receives the solar light and heat the moon is new—that is to say, that she is in conjunction, that she is situated between the sun and the earth. She is then, on account of the situation which she occupies in opposition when she is full, nearer the sun by the double of her distance from the earth. Now this distance may be estimated at the two-hundredth part of that which separates the sun and the earth; or, in round numbers, at two hundred thousand leagues. Therefore this visible face is nearer the sun by two hundred thousand leagues when it receives his rays.”
“Quite right,” replied Nicholl.
“Whilst—” resumed Barbicane.
“Allow me,” said Michel, interrupting his grave companion.
“What do you want?”
“I want to go on with the explanation.”
“Why?”
“To prove that I have understood.”
“Go on, then,” said Barbicane, smiling.
“Whilst,” said Michel, imitating the tone and gestures of President Barbicane, “when the visible face of the moon is lighted by the sun the moon is full—that is to say, situated with regard to the earth the opposite to the sun. The distance which separates it from the radiant orb is then increased in round numbers by 200,000 leagues, and the heat which it receives must be rather less.”
“Well done!” exclaimed Barbicane. “Do you know, Michel, for an artist you are intelligent.”
“Yes,” answered Michel carelessly, “we are all intelligent on the Boulevard des Italiens.”
Barbicane shook hands gravely with his amiable companion, and went on enumerating the few advantages reserved to the inhabitants of the visible face.
Amongst others he quoted the observations of the sun’s eclipses, which can only be seen from one side of the lunar disc, because the moon must be in opposition before they can take place. These eclipses, caused by the interposition of the earth between the sun and the moon, may last two hours, during which, on account of the rays refracted by its atmosphere, the terrestrial globe can only appear like a black spot upon the sun.
“Then,” said Nicholl, “the invisible hemisphere is very ill-treated by Nature.”
“Yes,” answered Barbicane, “but not the whole of it. By a certain movement of liberation, a sort of balancing on its centre, the moon presents more than the half of her disc to the earth. She is like a pendulum, the centre of gravity of which is towards the terrestrial globe, and which oscillates regularly. Whence comes that oscillation? Because her movement of rotation on her axis is animated with uniform velocity, whilst her movement of translation, following an elliptical orb round the earth, is not. At the perigee the velocity of translation is greater, and the moon shows a certain portion of her western border. At her apogee the velocity of rotation is greater, and a morsel of her eastern border appears. It is a strip of about eight degrees, which appears sometimes on the west, sometimes on the east. The result is, therefore, that of a thousand parts the moon shows five hundred and sixty-nine.”
“No matter,” answered Michel; “if we ever become Selenites, we will inhabit the visible face. I like light.”
“Unless,” replied Nicholl, “the atmosphere should be condensed on the other side, as certain astronomers pretend.”
“That is a consideration,” answered Michel simply.
In the meantime breakfast was concluded, and the observers resumed their posts. They tried to see through the dark port-light by putting out all light in the projectile. But not one luminous atom penetrated the obscurity.
One inexplicable fact preoccupied Barbicane. How was it that though the projectile had been so near the moon, within a distance of twenty-five miles, it had not fallen upon her? If its speed had been enormous, he would have understood why it had not fallen. But with a relatively slight speed the resistance to lunar attraction could not be explained. Was the projectile under the influence of some strange force? Did some body maintain it in the ether? It was henceforth evident that it would not touch any point upon the moon. Where was it going? Was it going farther away from or nearer to the disc? Was it carried along in the gloom across infinitude? How were they to know, how calculate in the dark? All these questions made Barbicane anxious, but he could not solve them.
In fact, the invisible orb was there, perhaps, at a distance of some leagues only, but neither his companions nor he could any longer see it. If any noise was made on its surface they could not hear it. The air, that vehicle of transmission, was wanting to convey to them the groans of that moon which the Arabian legends make “a man already half-granite, but still palpitating.”
It will be agreed that it was enough to exasperate the most patient observers. It was precisely the unknown hemisphere that was hidden from their eyes. That face which a fortnight sooner or a fortnight later had been, or would be, splendidly lighted up by the solar rays, was then lost in absolute darkness. Where would the projectile be in another fortnight? Where would the hazards of attraction have taken it? Who
