"The second reason is that we must not let the outer cold, which is excessive, penetrate the projectile or we shall be frozen to death.""But the sun?"
"The sun warms our projectile, which absorbs its rays; but it does not warm the vacuum in which we are floating at this moment.
Where there is no air, there is no more heat than diffused light;and the same with darkness; it is cold where the sun's rays do not strike direct. This temperature is only the temperature produced by the radiation of the stars; that is to say, what the terrestrial globe would undergo if the sun disappeared one day.""Which is not to be feared," replied Nicholl.
"Who knows?" said Michel Ardan. "But, in admitting that the sun does not go out, might it not happen that the earth might move away from it?""There!" said Barbicane, "there is Michel with his ideas.""And," continued Michel, "do we not know that in 1861 the earth passed through the tail of a comet? Or let us suppose a comet whose power of attraction is greater than that of the sun.
The terrestrial orbit will bend toward the wandering star, and the earth, becoming its satellite, will be drawn such a distance that the rays of the sun will have no action on its surface.""That _might_ happen, indeed," replied Barbicane, "but the consequences of such a displacement need not be so formidable as you suppose.""And why not?"
"Because the heat and cold would be equalized on our globe.
It has been calculated that, had our earth been carried along in its course by the comet of 1861, at its perihelion, that is, its nearest approach to the sun, it would have undergone a heat 28,000 times greater than that of summer. But this heat, which is sufficient to evaporate the waters, would have formed a thick ring of cloud, which would have modified that excessive temperature; hence the compensation between the cold of the aphelion and the heat of the perihelion.""At how many degrees," asked Nicholl, "is the temperature of the planetary spaces estimated?""Formerly," replied Barbicane, "it was greatly exagerated; but now, after the calculations of Fourier, of the French Academy of Science, it is not supposed to exceed 60@ Centigrade below zero.""Pooh!" said Michel, "that's nothing!"
"It is very much," replied Barbicane; "the temperature which was observed in the polar regions, at Melville Island and Fort Reliance, that is 76@ Fahrenheit below zero.""If I mistake not," said Nicholl, "M. Pouillet, another savant, estimates the temperature of space at 250@ Fahrenheit below zero.
We shall, however, be able to verify these calculations for ourselves.""Not at present; because the solar rays, beating directly upon our thermometer, would give, on the contrary, a very high temperature. But, when we arrive in the moon, during its fifteen days of night at either face, we shall have leisure to make the experiment, for our satellite lies in a vacuum.""What do you mean by a vacuum?" asked Michel. "Is it perfectly such?""It is absolutely void of air."
"And is the air replaced by nothing whatever?""By the ether only," replied Barbicane.
"And pray what is the ether?"
"The ether, my friend, is an agglomeration of imponderable atoms, which, relatively to their dimensions, are as far removed from each other as the celestial bodies are in space. It is these atoms which, by their vibratory motion, produce both light and heat in the universe."They now proceeded to the burial of Satellite. They had merely to drop him into space, in the same way that sailors drop a body into the sea; but, as President Barbicane suggested, they must act quickly, so as to lose as little as possible of that air whose elasticity would rapidly have spread it into space.
The bolts of the right scuttle, the opening of which measured about twelve inches across, were carefully drawn, while Michel, quite grieved, prepared to launch his dog into space. The glass, raised by a powerful lever, which enabled it to overcome the pressure of the inside air on the walls of the projectile, turned rapidly on its hinges, and Satellite was thrown out.
Scarcely a particle of air could have escaped, and the operation was so successful that later on Barbicane did not fear to dispose of the rubbish which encumbered the car.