My Air-Ships

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904 edition. Excerpt: ... CHAPTER IV My "brazil"--Smallest Of Spherical Balloons I Liked ballooning so much that, coming back from my first trip with M. Machuron, I told him that I wanted a balloon built for myself. He liked the idea. He thought that I wanted an ordinary-sized spherical balloon, between 500 and 2000 cubic metres in volume. No one would think of making one smaller. It is only a short time ago, but it is curious how constructors still clung to heavy materials. The smallest balloon basket had to weigh 30 kilogrammes (66 lbs.). Nothing was light-- neither envelope, rigging, nor accessories. I gave M. Machuron my ideas. He cried out against it when I told him I wanted a balloon of the lightest and toughest Japanese silk, 100 cubic metres (about 3500 cubic feet) in volume. At the works both he and M. Lachambre tried to prove to me that the thing was impossible. How often have things been proved to me impossible! Now I am used to it I expect it. But in those days it troubled me. Still I persevered. They showed me that for a balloon to have "stability" it must have a certain weight. Again, a balloon of 100 cubic metres, they said, would be affected by the movements of the aeronaut in his basket much more than a large balloon of regulation size. With a large balloon the centre of gravity in the weight of the aeronaut is as in Fig. 1, a. When the aeronaut moves, say, to the right in his basket, Fig. 1, b, the centre of gravity of the whole system is not shifted appreciably. In a very small balloon the centre of gravity, Fig. 2, , is undisturbed only so long as the aeronaut sits straight in the centre of his basket. When he moves to the right the centre of gravity, Fig. 2, b, is shifted beyond the vertical line of the balloon's circumference, causing...