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.