Instantly those dull-glass screens were alive with light, and it was as though we were gazing forth from the very tip of the power-tower out over our gathered mass of cities. North and east and south and west, from all the screens about us the views were alike, of a tremendous mass of clustered metal towers that encircled New York. Below us was the screen, above which our metal seats were suspended on supports. It seemed a trap-door through which we were gazing down toward the green plains far beneath; though in reality all the city's massive base lay between us and that view. So intensely realistic was the scene that lay about us that we all but forgot the great circular room in which we really were, and seemed suspended high in air above the great mass of our gathered air-cities. "The enemy armadas," said Yarnall, his voice low, "will be in sight within fifteen minutes." For upon the map the two masses of red circles were rushing on from east and west, and seemed now almost upon the mass of circles that was our own great fleet of cities. Looking out over those cities, through the periscopic screens about us, we could see the forts raising their great guns to firing range. I realized, as I saw it, that the battle now ready to start would mean annihilation to half the world. This was indeed Armageddon, when on earth itself was left no human being at peace; when every nation was rushing through the air toward this last conflict! Now, however, Yarnall touched another control, and from the electrostatic tower's tip, high above us flashed great signals of brilliant lights that were taken up and repeated from all the power-towers of all the hundred cities that ringed us round. And, as those signals flashed, the great crowds that filled the streets of the air-cities were suddenly flowing out of those streets into the cities' towers; until within a few moments none were visible in all the streets and plazas, save those black-uniformed men who stood ready at the great heat-guns of our batteries. And those crowds went quietly, despite their tense excitement, because they knew that they were being ordered inside for their greater protection. There was no refuge upon the earth's surface far beneath, for them; when the destructive powers of all the world were battling above it in the air.