German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen that later were called Zeppelins; the first of which had its maiden flight in 1900.
O conde alemán Ferdinand von Zeppelin promoveu a idea de utilizar o hidróxeno para elevar aeronaves ríxidas, máis tarde chamadas zepelines, a primeira das cales tivo o seu voo inaugural en 1900.