Page:My Airships.djvu/109

 liberty. And yet when moving horizontally—as you would say, in the natural position—a glance downwards at the house-tops disquieted me. "What if I should fall?" the thought came. The house-tops looked so dangerous with their chimney-pots for spikes. One seldom has this thought in a spherical balloon, because we know that the danger in the air is nil: the great spherical balloon can neither suddenly lose its gas nor burst. My little air-ship balloon had to support not only exterior but interior pressure as well—which is not the case with a spherical balloon, as I shall explain in the next chapter—and any injury to the cylindrical form of my air-ship balloon by loss of gas might prove fatal. While over the house-tops I felt that it would be bad to fall, but as soon as I left Paris and was navigating over the forest of the Bois de Boulogne the idea left me entirely. Below there seemed to be an ocean of greenery, soft and safe. It was while over the continuation of this greenery in the grassy pelouse of the Longchamps racecourse that my balloon, having lost a great deal of its gas, began to double on itself. Previously I had heard a noise. Looking up, I saw