L'Intrépide or Hércule flown at the siege of Mainz (1795)

 

L'Intrépide was the larger of two observation balloons, the other being Hercule ("Hercules"), issued to the Aerostatic Corps in June 1795, twelve years after the pioneering hydrogen balloon flights of Professor Jacques Charles and the Robert brothers in Paris. These balloons were used by the Corps's first company attached to General Jourdan's Army of Sambre-et-Meuse in 1796. When that army was defeated by Austrian forces at the Battle of Würzburg on 3 September 1796, the balloon was captured and taken to Vienna, where it is now on display at the Heeresgeschichtliches Museum.

 

 

The actual preserved envelope is the sole survivor of the world’s first military air fleet - and possibly the world’s oldest surviving aircraft.

 

 

The balloon's silk envelope is roughly spherical and has a diameter of 9.8 metres (32 ft). Its wooden gondola is very small, measuring 1.14 metres (45 in) by 0.75 metres (30 in) and its railing has a height of 1.05 metres (41 in). The hull displayed in the museum is a replica, with the original displayed in a glass box nearby.