Note: my Hindenbustang above is very small for an airship, but it is not filled with Helium or Hydrogen at last (too heavy 90g/m³) but with little mechanical vacuum (60g/m³, far from the big mechanical vacuum 1g/m³ that would require very solid/heavy cover). Is this invention an old one, obviously impossible, or a new one, geniously by myself for a new World??