When you visit our website, if you give your consent, we will use cookies to allow us to collect data for aggregated statistics to improve our service and remember your choice for future visits. Cookie Policy & Privacy Policy
Dear Reader, we use the permissions associated with cookies to keep our website running smoothly and to provide you with personalized content that better meets your needs and ensure the best reading experience. At any time, you can change your permissions for the cookie settings below.
If you would like to learn more about our Cookie, you can click on Privacy Policy.
Moreover, in case of an accident happening to the outside balloon, such as getting torn, for instance, the other would remain intact. The balloons were made of a strong but light Lyons silk, coated with gutta percha. This gummy, resinous substance is absolutely water-proof, and also resists acids and gas perfectly. The silk was doubled, at the upper extremity of the oval, where most of the strain would come. Such an envelope as this could retain the inflating fluid for any length of time. It weighed half a pound per nine square feet. Hence the surface of the outside balloon being about eleven thousand six hundred square feet, its envelope weighed six hundred and fifty pounds. The envelope of the second or inner balloon, having nine thousand two hundred square feet of surface, weighed onl