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.