Vacuum Airship

> I thought up the idea of using a vacuum for lifting an airship
> years ago. One thing though...you don't need a compleat vacuum so
> your envelope may not have to be so strong.

Now this is a thought. Perhaps helium at high temperatures and very
low pressures? Something the size of nine blimps, using the same mass
of helium as one uses now? And as we improve the envelope, we use
less and less, until it really is a vacuum airship.