Secret History of Airships
An airship or dirigible is a type of aerostat or lighter-than-air aircraft that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms. Unlike aerodynamic aircraft such as fixed-wing aircraft and helicopters, which produce lift by moving a wing through the air, aerostatic aircraft stay aloft by having a large "envelope" filled with a gas which is less dense than the surrounding atmosphere.
The first lifting gas used was hydrogen, although this had well-known concerns over its flammability. Helium was rare in most parts of the world, but large amounts were discovered in the USA. This meant that this non-flammable gas was rarely used for airships outside of the USA. All modern airships, since the 1960s, use helium.
Fabulous stuff, man - http://www.youtube.com/watch?v=biZFg_H8i88 (http://www.youtube.com/watch?v=biZFg_H8i88)
(http://farm1.static.flickr.com/145/434448559_337e2ae8d9.jpg)