* Lighter than Air: Hydrogen is the lightest element and has a density significantly lower than air. This means a large volume of hydrogen gas can lift a considerable weight, making it ideal for lifting airships.
* Abundant and Relatively Cheap: Hydrogen was relatively easy and inexpensive to produce in the early 20th century. It could be created by electrolysis of water or by reacting various chemicals.
* Early Technology: In the early days of airship development, helium was not widely available or affordable. It was only discovered in 1868 and remained difficult to extract until the 1920s. Hydrogen was the only practical option.
However, hydrogen also has a major disadvantage:
* Highly Flammable: Hydrogen is highly flammable, making it incredibly dangerous for airship travel. Several zeppelins filled with hydrogen suffered catastrophic fires, most notably the Hindenburg disaster in 1937.
The Hindenburg disaster ultimately led to the phasing out of hydrogen in airships and the adoption of helium as the primary lifting gas. Helium is significantly safer, being non-flammable, although it is more expensive and less buoyant than hydrogen.
