to do, or see, that is more than usually interesting?" said Burgoyne.
"No. We shall remain on this satellite, and be carried round with it. It's not safe to approach any closer. If anything happens I will call you; my long sleep has left me quite fresh, so I shall take a number of photographs," replied the scientist, turning to his array of cameras.
Burgoyne and the Austrian were soon enfolded in their rugs. But Flint, always deeply interested in his master's work, watched and aided him with his cameras. From one of the windows they looked directly down on the heaving, gaseous surface of the monster planet; from another, the sun was visible, but appeared little more than a star of intense brilliancy amid a host of other lesser points of luminosity. As the satellite moved round its parent orb, Flint remarked in surprize that it always appeared in the same relative position to them.
"Should have thought it would have gone out of sight," said he, referring to the vast globe.
"But this moon is like our satellite," explained his master. "It always keeps the same hemisphere facing inward—it's a peculiarity moons have."
As the hours sped by they noted that though the huge planet shone with the dull light of its own fiery gases, yet it was markedly brighter where the sunlight fell upon it. It was new, crescent, half, and full, in turns.
Ten hours after their grounding Carscadden made a careful study of his registers and instruments, and afterward was busy for a little while with his pencil. Then he made the following announcement:
"Since we landed, Jupiter, as well as Mars and the earth, has moved and altered its relative position considerably. From here to our planet, in a direct line, is now nearly 700,000,000 miles. Our air supply, I find, will last the four of us just seventy-nine hours; that is using up the compressed stores and the reserve oxygen. That means that we shall have to travel at express speed, in spite of the risk; we have no margin of safety for possible emergencies at the end of our long journey. Your presence, Kobloth, is most inconvenient, not to say dangerous. Three would be able to exist in the Neutralia for over a hundred hours. If we can avoid the one danger that I fear, we need not use the ejector door for undesirable passengers." His voice was quite courteous, very grave, and yet hard as granite.
"And that one danger is?" asked Kobloth, whose face had grown gray and anxious.
"The danger of starting the Neutralia at a wrong angle. If we do not go absolutely straight to the earth we shall inevitably be drawn into the sun. And with so small a reserve of air we cannot afford to check our terrific pace in time to avert that fate," replied Carscadden quietly.
"When do we start?" inquired Burgoyne, who was impressed by their leader's quiet statement.
"In half an hour—if we can."
10. An Error of a Decimal
"What's to hinder us starting?" asked Flint, first voicing the surprize of the three listeners.
"Our path—I have just found that it will take us directly across the path of Jupiter's fourth satellite. In half an hour, when we must cross its path, it will be there, or very nearly so. At least it will be no more than .10513 of its diameter away from the point of intersection. I need not say that the margin is far too narrow for safety."
