"All our American Federation air-cities," Macklin told me: "are massed together, hanging south of the Great Lakes. From Buenos Aires to Winnipeg, they've come." "You think, then, that the European and Asiatic Federation air-cities are going to make a simultaneous attack from both sides?" I shouted to him above the roaring of our flight. He nodded emphatically. "Undoubtedly. The Asiatic Federation cities are over the Pacific now, and are keeping in touch with the European ones by distance-phone to time their attack to coincide from east and west. They know our own cities have massed together, must know now that they've been equipped with the great new speed-tubes also; but they're coming on." "Two to one," I said: "Two hundred air-cities attacking our one hundred. God, what a battle it will be!" But now Hilliard had broken into our conversation, was pointing far ahead toward a dark, flat mass that stood out against the brilliant western sky, and toward which we were moving. The terrific speed at which we had been racing on for hours was decreasing now. Far beneath the land was still rolling back at great speed, long green plains now; since already we had flashed west over the Alleghanies. Then, as the dark mass westward grew steadily with our approach to it, other ships were driving suddenly beside our own, watchful patrols that drove down upon our hundred cruisers and swiftly challenged them. Macklin answered those challenges by the distance-phone, but for the moment I paid small attention to him, gazing forward with heart beating rapidly at the great mass that hung high in mid-air before us. For, as we drove closer toward that mass, it was becoming visible to our eyes as our goal, the hundred giant air-cities of the American Federation! The hundred mighty American Federation air-cities were clustered there miles above the green plains, in a great circular mass, with New York, most colossal of all of them, at the center! Cities that had long hung over North and South America from sea to sea, air-cities whose names were those of the long-vanished cities of the land, that once had dotted the surface of those continents. Boston and Los Angeles, Rio de Janeiro and Chicago, Mexico City and Quebec, Valparaiso and Miami--these and scores of others hung there in that great cluster. All the air-cities of the American Federation were gathered here about their air-capital of New York to withstand the tremendous attacks now closing in from east and west!