had the advantage in that the weight of Blau gas was near that of air. Thus the use of large quantities of Blau gas as a propellant had little impact on the Zeppelin buoyancy. Blau gas was used on the Zeppelin airship's first voyage to America, starting in 1929. The Zeppelin facility in Friedrichshafen produced the Blau gas. History Early designs Count Ferdinand von Zeppelin's serious interest in airship development began in 1874, when he took inspiration from a lecture given by Heinrich von Stephan on the subject of "World Postal Services and Air Travel" to outline the basic principle of his later craft in a diary entry dated 25 March 1874. This describes a large rigidly framed outer envelope containing several separate gasbags. He had previously encountered Union Army balloons in 1863 when he visited the United States as a military observer during the American Civil War. Count Zeppelin began to seriously pursue his project after his early retirement from the military in 1890 at the age of 52. Convinced of the potential importance of aviation, he started working on various designs in 1891, and had completed detailed designs by 1893. An official committee reviewed his plans in 1894, and he received a patent, granted on 31 August 1895, with Theodor Kober producing the technical drawings. Zeppelin's patent described a [Steerable aircraft with several carrier bodies arranged one behind another], an airship consisting of flexibly articulated rigid sections. The front section, containing the crew and engines, was 117.35 m (385 ft) long with a gas capacity of 9,514 m³ (336,000 cu ft): the middle section was 16 m (52 ft 6 in) long with an intended useful load of 599 kg (1,320 lb) and the rear section 39.93 m (131 ft) long with an intended load of 1,996 kg (4,400 lb). Count Zeppelin's attempts to secure government funding for his project proved unsuccessful, but a lecture given to the Union of German Engineers gained their support. Zeppelin also sought support from the industrialist Carl Berg, then engaged in construction work on the second airship design of David Schwarz. Berg was under contract not to supply aluminium to any other airship manufacturer, and subsequently made a payment to Schwarz's widow as compensation for breaking this agreement. Schwarz's design differed fundamentally from Zeppelin's, crucially lacking the use of separate gasbags inside a rigid envelope. In 1898 Count Zeppelin founded the Gesellschaft