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Full of Hot Air

The hot-air balloon is the oldest successful human-carrying flight technology and is a subset of balloon aircraft. On Nov 21, 1783, in Paris, the first untethered manned flight was made by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes in a hot-air balloon created on Dec. 14, 1782 by the Montgolfier brothers. Recently, balloon envelopes have been made in all kinds of shapes, such as hot dogs, rocket ships and the shapes of commercial products. Hot-air balloons that can be propelled through the air rather than just being pushed along by the wind are known as airships or, more specifically, thermal airships.

Annual balloon festival, Albuquerque, N.M. 2006. Prints and Photographs Division. Reproduction Information: Reproduction No.: LC-DIG-highsm-04874 (original digital file); Call No.: LC-DIG-highsm- 04874 (ONLINE) [P&P] Balloonists George Howard and Leslie Haddock, fliers of the balloon Cincinnati, standing outdoors, during a balloon race. 1908. Chicago History Museum. Reproduction Information: Reproduction No.: SDN-054000

A hot-air balloon consists of a bag called the envelope that is capable of containing heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries passengers and a source of heat – in most cases an open flame. The heated air inside the envelope makes it buoyant since it has a lower density than the relatively cold air outside the envelope. Unlike gas balloons, the envelope does not have to be sealed at the bottom since the air near the bottom of the envelope is at the same pressure as the surrounding air. In today's sport balloons, the envelope is generally made from nylon fabric and the mouth of the balloon (closest to the burner flame) is made from fire-resistant material such as Nomex.

The Library’s Preservation Directorate has conducted a study of fabric samples from 18th- to 19th-century lighter-than-air balloons. Analysis addresses the identity of the component materials, as well as their state of degradation. Results of the analysis will assist Library conservators in the preservation treatment and housing of the fabric samples and are expected to contribute to a better understanding of the history of technology of balloon aeronautics.

The American Memory collection “Photographs from the Chicago Daily News” contains several images of hot-air balloons and balloon racing.