But if Uncle Prudent wished to ask Robur to take him eastwards he could not then do so. That morning the engineer did not leave his cabin. Either he was occupied in some work, or else he was asleep, and the two colleagues sat down to breakfast without seeing him. The speed was the same as that during last evening. The wind being easterly the rate was not interfered with at all, and as the thermometer only falls a degree centigrade for every seventy meters of elevation the temperature was not insupportable. And so, in chatting and thinking and waiting for the engineer, Uncle Prudent and Phil Evans walked about beneath the forest of screws, whose gyratory movement gave their arms the appearance of semi-diaphanous disks. The State of Illinois was left by its northern frontier in less than two hours and a half; and they crossed the Father of Waters, the Mississippi, whose double-decked steam-boats seemed no bigger than canoes. Then the “Albatross” flew over Iowa after having sighted Iowa City about eleven o’clock in the morning. A few chains of hills, “bluffs” as they are called, curved across the face of the country trending from the south to the northwest, whose moderate height necessitated no rise in the course of the aeronef. Soon the bluffs gave place to the large plains of western Iowa and Nebraska—immense prairies extending all the way to the foot of the Rocky Mountains. Here and there were many rios, affluents or minor affluents of the Missouri. On their banks were towns and villages, growing more scattered as the “Albatross” sped farther west. Nothing particular happened during this day. Uncle Prudent and Phil Evans were left entirely to themselves. They hardly noticed Frycollin sprawling at full length in the bow, keeping his eyes shut so that he could see nothing. And they were not attacked by vertigo, as might have been expected. There was no guiding mark, and there was nothing to cause the vertigo, as there would have been on the top of a lofty building. The abyss has no attractive power when it is gazed at from the car of a balloon or deck of an aeronef. It is not an abyss that opens beneath the aeronaut, but an horizon that rises round him on all sides like a cup. In a couple of hours the “Albatross” was over Omaha, on the Nebraskan frontier—Omaha City, the real head of the Pacific Railway, that long line of rails, four thousand five hundred miles in length, stretching from New York to San Francisco. For a moment they could see the yellow waters of the Missouri, then the town, with its houses of wood and brick in the center of a rich basin, like a buckle in the iron belt which clasps North America round the waist. Doubtless, also, as the passengers in the aeronef could observe all these details, the inhabitants of Omaha noticed the strange machine. Their astonishment at seeing it gliding overhead could be no greater than that of the president and secretary of the Weldon Institute at finding themselves on board.