I was now working on my plane with the keenest enthusiasm, for I now saw rapidly taking form such a ship as, I truly believe, might be built nowhere in the universe other than in Havatoo. Here I had at my disposal materials that only the chemists of Havatoo might produce, synthetic wood and steel and fabric that offered incalculable strength and durability combined with negligible weight. I had also the element, vik-ro, undiscovered on earth, and the substance, lor, to furnish fuel for my engine. The action of the element, vik-ro, upon the element, yor-san, which is contained in the substance, lor, results in absolute annihilation of the lor. Some conception of the amount of energy thus released may be obtained by considering the fact that there is eighteen thousand million times as much energy liberated by the annihilation of a ton of coal as by its combustion. Fuel for the life of my ship could be held in the palm of my hand, and with the materials that entered into its construction the probable life of the ship was computed by the physicists working on it to be in the neighborhood of fifty years. Can you wonder that I looked forward with impatience to the completion of such a marvel ship! With it I would be sure to find Duare. At last it was finished! I spent the final afternoon checking it over carefully with my large corps of assistants. On the morrow it was to be wheeled out for my trial flight. I knew that it would be successful. All my assistants knew that it would be; it was a scientific certainty that it must fly. That evening I determined to indulge in a little relaxation; and I called Nalte on the wireless, transmitterless, receiverless communicating system that is one of the wonders of Havatoo. I asked her if she would take dinner with me, and she accepted with an alacrity and display of pleasure that warmed my heart. We dined in a little public garden on the roof of a building at the corner of Yorgan Lat and Havatoo Lat, just inside the river wall. "It seems good to see you again," said Nalte. "It has been a long time--not since the war games. I thought you had forgotten me." "Far from it," I assured her, "but I have been working day and night on my airship." "I have heard some mention of it," she said, "but no one that I have talked with seemed to understand very much about it. Just what is it and what will it do?" "It is a ship that flies through the air faster than a bird can wing," I replied. "But what good will that be?" she demanded. "It will carry people quickly and safely from one place to another," I explained. "You don't mean to say that people will ride in it!" she exclaimed. "Why, certainly; why else should I build it?" "But what will keep it in the air? Will it flap its wings like a bird?" "No; it will soar like a bird on stationary wings." "But how will you get through the forests where the trees grow close together?" "I shall fly over the forests."