"By filling the vestibule as full as possible," said Bearwarden, "and so displacing most of its air, we shall be able to open the outside door oftener without danger of rarefaction."
The things they had discharged flew off with considerable speed and were soon out of sight; but it was not necessary for them to move fast, provided they moved at all, for, the resistance being nil, they would be sure to go beyond the range of vision, provided enough time was allowed, even if the Callisto's speed was not being increased by apergy, in which case articles outside and not affected would be quickly left behind.
The earth, which at first had filled nearly half their sky, was rapidly growing smaller. Being almost between themselves and the sun, it looked like a crescent moon; and when it was only about twenty times the size of the moon they calculated they must have come nearly two hundred thousand miles. The moon was now on what a sailor would call the starboard bow--i. e., to the right and ahead. Being a little more than three quarters full, and only about fifty thousand miles off, it presented a splendid sight, brilliant as polished silver, and about twenty-five times as large as they had ever before seen it with the unaided eye.
It was just ten hours since they had started, and at that moment 9 A. M. in New York; but, though it was night there, the Callisto was bathed in a flood of sunlight such as never shines on earth. The only night they would have was on the side of the Callisto turned away from the sun, unless they passed through some shadow, which they intended to avoid on account of the danger of colliding with a meteor in the dark. The moon and the Callisto were moving on converging lines, the curve on which they had entered having swung them to the side nearest the earth; but they saw that their own tremendous and increasing speed would carry them in front of the moon in its nearly circular orbit. Wishing to change the direction of their flight by the moon's attraction, they shut off the power driving them from the earth, whereupon the Callisto turned its heavy base towards the moon. They were already moving at such speed that their momentum alone would carry them hundreds of thousands of miles into space, and were then almost abreast of the earth's satellite, which was but a few thousand miles away. The spectacle was magnificent. As they looked at it through their field glasses or with the unaided eye, the great cracks and craters showed with the utmost clearness, sweeping past them almost as the landscape flies past a railway train. There was something awe-inspiring in the vast antiquity of that furrowed lunar surface, by far the oldest thing that mortal eye can see, since, while observing the ceaseless political or geological changes on earth, the face of this dead satellite, on account of the absence of air and water and consequent erosion, has remained unchanged for bygone ages, as it doubtless will for many more.
They closely watched the Callisto's course. At first it did not seem to deflect from a straight line, and they stood ready to turn on the apergetic force again, when the car very slowly began to show the effect of the moon's near pull; but not till they had so far passed it that the dark side was towards them were they heading straight for Jupiter. Then they again turned on full power and got a send-off shove on the moon and earth combined, which increased their speed so rapidly that they felt they could soon shut off the current altogether and save their supply.
"We must be ready to watch the signals from the arctic circle," said Bearwarden. "At midnight, if the calculations are finished, the result will be flashed by the searchlight." It was then ten minutes to twelve, and the earth was already over four hundred thousand miles away. Focusing their glasses upon the region near the north pole, which, being turned from the sun, was towards them and in darkness, they waited.
"In this blaze of sunlight," said Cortlandt, "I am afraid we can see nothing."
Fortunately, at this moment the Callisto entered the moon's tapering shadow.
"This," said Ayrault, "is good luck. We could of course have gone into the shadow; but to change our course would have delayed us, and we might have lost part of the chance of increasing our speed."
"There will be no danger from meteors or sub-satellites here," said Bearwarden, "for anything revolving about the moon at this distance would be caught by the earth."