Now, as we sat tensely there, I had turned, nodded to Whitely, and he had thrown open the switches before him that controlled the great generators, their throbbing suddenly sounding behind us as they went into operation, generating the force-vibrations that in a moment would be released backward from our flier as mighty force-rays. As Whitely moved the switches, the throb of the generators died to a thin hum, then rose to a tremendous drone, and then slowly sank to a smooth throbbing beat at which he rested the switches. And now Marlin, beside me, was calling out to us the divisions of the specially-designed telescope's field, as Neptune passed across them to the zero mark at which we would hurtle outward. "--45--40--35--30--" As his steady voice sounded periodically beside me I sat as though a poised statue, my hand upon that lever among the six lever-switches before me that would send the power of our throbbing generators stabbing out with colossal force from the flier's ray-opening behind us, that would send that flier hurtling outward. "--25--20--15--." As the calm voice of Marlin broke the silence beside me I felt my heart racing with excitement, saw that Randall, and even Whitely, beside me, had hunched tensely forward as the moment approached. I glanced out a moment through the flier's windows, seeing in a blurred impression the breathless, watching crowds, the brilliant lights. "--10--5--_zero_!" And as that last word sounded I threw open in one swift motion the lever-switch in my grasp! The next instant there was a colossal roaring about us, we seemed pressed down in our chairs with titanic, crushing force, and saw crowds and lights and great buildings vanishing from about our flier with lightning-like swiftness as a great pale ray of light, of colossal force, stabbed down and backward from the flier's ray-opening behind us! In a split-second all about us was blackness and then the great roaring sound about us had ceased, marking our passage out past the limits of Earth's atmosphere! Now through the windows before and about us, as we clung there, we saw the heavens around us brilliant with the fierce light of undimmed hosts of stars, while as our great flier reeled on at mounting speed into the great gulf, we saw behind and beneath us a great gray cloudy ball that was each moment contracting in size. Earth was receding and diminishing behind us as we flashed out through the void toward distant Neptune, to save that Earth from doom! [Illustration: _We sat again in our chairs before the control-panel, Whitely to my left, gazing through the big window before us ... soaring past the limits of Earth's atmosphere._] CHAPTER IV Through Planetary Perils "Mars ahead and to the left--we ought to pass it in three more hours!" At my words Marlin nodded. "We won't be bothered much by the pull of Mars," he said.