To her consternation, she also floated upward and, still in a graceful sitting posture, sailed slowly up to the ceiling to Bennie's side. Burke shook with laughter. "Human Zeppelins, by thunder! How are you ever going to get down again?" Rhoda wrapped her skirts tightly around her ankles with one hand and waved to Burke with the other. "Why don't you come up and join us? It's fine!" Professor Hooker assumed an expression of great solemnity. "Action and reaction--to use the words of one I. Newton--are equal and opposite in their effects," he declaimed, giving Rhoda a slight push to one side, which caused them to drift apart until they bumped lightly against the opposite walls of the room. "Isn't this great? If we'd only brought along some balls and cues, we could play billiards in three dimensions." Burke had thrust his face close to the deadlight and was peering down into the abyss of space that yawned below. "By George," he cried, "you're missing something! Better come down here and take a look." "But how shall I _get_ down?" gasped Rhoda, in great embarrassment. "What on earth shall I do!" "Not what you do on earth," grinned Bennie. "Grab a life-line and pull yourself down. We're in the center of the universe--so to speak." Together they slowly drew themselves back to the chart-table by means of the clothes-lines and then to the deadlight. The glare from the tractor had now entirely disappeared, and the Ring swam in the Stygian darkness of space. Their first impression was that the earth had vanished. In its place was a vast black firmament crowded with millions of blazing worlds. Though the great orb of the moon was full, and shone like a sun through the pure ether above their heads, the lunar light, undiluted and undimmed by the earth's atmosphere, diminished in no way the brilliancy of the stars. It was a new and marvelous effect--the black-velvet robe of night studded with incandescent and apparently motionless orbs, which gleamed like resplendent meteors in countless myriads on every side, but with a calm and absolutely steady light. Then, as they looked, they saw, just below them, what appeared to be a vast black hole in the darkness, covering perhaps one-tenth of the sky, within which not a single star could be seen. "Put out the lights," directed Bennie, rubbing off with his handkerchief the condensation, due to the intense cold of interplanetary space, which had formed on the inside of the deadlight. And now, as their eyes grew accustomed to the darkness, they saw that the great circle in the galaxy of stars was not quite black but shone with a pale-gray, ashen phosphorescence, through which they could eventually discern the outlines of the continents of North and South America. This huge circular disk, which blotted out so much of the night below them, was naught but the dark side of the earth illumined by the light of the moon alone.