As the time passed the Earth appeared smaller and smaller. Its farther edge, still obscuring a slice of the sun, produced much the same effect as a partial eclipse of the sun by the moon when seen from the Earth. The physical features of the Earth were no longer visible against the glare of the sun. It simply looked like a black disk, slightly larger than the moon. About this time their self-invited companion seemed a good deal perplexed over something. He stood shifting his weight from one foot to the other with a look of comical mystification on his ruddy countenance. “What’s the matter, old man?” asked Robert, much amused at Taggert’s curious antics. “Cootie?” “Something wrong here,” giving a little hop. “I’ll admit you show symptoms of it, young man,” remarked the professor, dryly. “Feel kind of lightish. Maybe I’m going to become an angel when we get a little higher,” went on the redhead, still engrossed in his private calculations. “Come to think about it,” said Robert, standing up, “I feel somewhat that way myself. It must be contagious.” They both looked toward Professor Palmer keenly, as if expecting him to show similar symptoms. The professor laughed long and heartily, until the pair became convinced that there was something wrong with him, too. “Well, boys, it’s this way,” he said at last; “the farther away from the Earth we get, the weaker its attraction for us becomes. Of course you feel lighter--you _are_ lighter--and that’s not all. Before we reach Mars, we shall all weigh nothing. We’ll be floating around in here like toy balloons.” “That’s a fact,” said Robert after a moment’s reflection. “But I hadn’t thought of it until now.” “Well, you fellows can swim around like goldfish if you want, but I’m going to find an anchor,” declared Taggert, looking round for a likely object of promising bulk and solidity. “No use,” replied Professor Palmer. “When you float, everything else that is loose floats, too.” Taggert scratched his red head thoughtfully. “All right, then,” he said finally, in mock despair, “float it is; we’ll all play tag.” A little while later the sun appeared unobstructed. The Earth had shrunk so small this time that it could no longer be seen on account of its close proximity to the sun. Well beyond it the moon hung serenely, though considerably reduced in size. Seen from this angle it was now nearer half than full. Oddly enough, in all directions the heavens presented the same appearance as when seen from the Earth at night, though the sun shone brightly upon the _Sphere_. “But why?” Taggert wanted to know, looking in perplexity toward the blazing sun and then at the stars twinkling in cold, brilliant splendor.