"I have a pleasant surprise for you," he told them in his musical baritone. "Our planetary conference would wish for me to give you a most pleasant impression of Jupiter, so that interplanetary relations may be resumed under the best possible conditions. For that reason I am going to land you on a satellite that I'll wager will be a revelation to you. It is the goal and object of every one of our people. But it is costly and only a small portion of our population can be accommodated at a time. You may judge the kind of place it is by the name the public has given it: 'The Pleasure Bubble.' Come to the astrogator's cabin now; I'll show it to you."
They followed Musters to a compartment in the rounded bow of the great ship, stared out of a quartz port between opened shutters.
They saw Jupiter, immense, formidable, a mass of turbulent vapors, a depressingly drab scene. Suddenly Lents exclaimed, incredulous;
"Look! A satellite! There is no satellite this close to Jupiter! It's mathematically impossible!"
Musters laughed jovially. "It's there, isn't it? That's Jupiter's tenth satellite—The Bubble. It is less than 100,000 miles from the vapor envelope and has to travel so fast that its period is less than 8 hours. It was built by the First Race and set on its orbit so that our people would have a place where they could enjoy the sun, which is never seen from Jupiter's surface."
"It is a bubble!" Kass remarked, after an absorbed study of the satellite. It was racing just beneath them, at a dizzy speed, like a bubble blown before the wind. The ship followed the satellite, drawing closer, so that it grew in size and beauty.
Lents was mentally calculating the rupturing pressure exerted by the atmospheric pressure inside the crystalline ball. He stopped aghast at the thought of the tremendous strain.
"That crystalline material stands the strain easily," Musters assured them. "It will resist anything but a direct hit by a very large meteorite. As you can see now, the sphere, which is about a mile in diameter, is bi-sected by a plane surface, on which the city is built. In that little area you will see reproduced the choicest conditions of Earth." He turned earnest, hungry eyes on them:
"You don't know how lucky you people of Earth are!"