Their domestic life, as Zaidie and Redgrave saw it while they were the guests of their host, was the perfection of simplicity and comfort, and their public life was characterised by a quiet but intense intellectuality which, as Zaidie had said, made them feel very much like children who had only just learnt to speak.
As they possessed magnificent telescopes, far surpassing any on Earth, their guests were able to survey, not only the Solar System, but the other systems far beyond its limits as no others of their kind had ever been able to do before. They did not look through or into the telescopes. The lens was turned upon the object, and this was thrown, enormously magnified, upon screens of what looked something like ground glass some fifty feet square. It was thus that they saw, not only the whole visible surface of Jupiter as he revolved above them and they about him, but also their native Earth, sometimes a pale silver disc or crescent close to the edge of the Sun, visible only in the morning and the evening of Jupiter, and at other times like a little black spot crossing the glowing surface.
But there was another development of the science of the Crystal Cities which interested them far more than this—for after all they could not only see the Worlds of Space for themselves, but circumnavigate them if they chose.
During their stay they were shown on these same screens the pictorial history of the world whose guests they were. These pictures, which they recognised as an immeasurable development of what is called the cinematograph process on Earth, extended through the whole gamut of the satellite's life. They formed, in fact, the means by which the children of Ganymede were taught the history of their world.
It was, of course, inevitable that the Astronef should prove an object of intense interest to their hosts. They had solved the problem of the Resolution of Forces, as Professor Rennick had done, and, as they were shown pictorially, a vessel had been made which embodied the principles of attraction and repulsion. It had risen from the surface of Ganymede, and then, possibly because its engines could not develop sufficient repulsive force, the tremendous pull of the giant planet had dragged it away. It had vanished through the cloud-belts towards the flaming surface beneath—and the experiment had never been repeated.
Here, however, was a vessel which had actually, as Redgrave had convinced his hosts by means of celestial maps and drawings of his own, left a planet close to the Sun, and safely crossed the tremendous gulf of six hundred and fifty million miles which separated Jupiter from the centre of the system. Moreover, he had twice proved her powers by taking his host and two of his newly-made friends, the chief astronomers of Ganymede, on a short trip across Space to Calisto and Europa, the second satellite of Jupiter, which, to their very grave interest, they found had already passed the stage in which Ganymede was, and had lapsed into the icy silence of death.
It was these two journeys which led to the last adventure of the Astronef in the Jovian System. Both Redgrave and Zaidie had determined, at whatever risk, to pass through the cloud-belts of Jupiter, and catch a glimpse, if only a glimpse, of a world in the making. Their host and the two astronomers, after a certain amount of quiet discussion, accepted their invitation to accompany them, and on the morning of the eighth day after their landing on Ganymede, the Astronef rose from the plain outside the Crystal City, and directed her course towards the centre of the vast disc of Jupiter.
She was followed by the telescopes of all the observatories until she vanished through the brilliant cloud-band, eighty-five thousand miles long and some five thousand miles broad, which stretched from east to west of the planet. At the same moment the voyagers lost sight of Ganymede and his sister satellites.
The temperature of the interior of the Astronef began to rise as soon as the upper cloud-belt was passed. Under this, spread out a vast field of brown-red cloud, rent here and there into holes and gaps like those storm-cavities in the atmosphere of the Sun, which are commonly known as sun-spots. This lower stratum of cloud appeared to be the scene of terrific storms, compared with which the fiercest earthly tempests were mere zephyrs.
After falling some five hundred miles further they found themselves surrounded by what seemed an ocean of fire, but still the internal temperature had only risen from seventy to ninety-five. The engines were well under control. Only about a fourth of the total R. Force was being developed, and the Astronef was dropping swiftly, but steadily.