What is "gasbags"

Usage examples of "gasbags".

Just as when they had been wild and free, they had no propulsion systems of their own other than the ability to add hydrogen to, or remove it from, the contents of their gasbags, and thus to move up or down at will.

A geyser of flame went tearing up the companion-ladders between the gasbags and blew out the top of the envelope.

Despite its fantastic thinness, there were molecule-thin murals worked onto it: titanic scenes of Investor argosies where wily Investors had defrauded pebbly bipeds and gullible heavy-planet gasbags swollen with wealth and hydrogen.

The vast, extended silver cigar was built externally on the ancient zeppelin pattern but with an industrial stasis generator and a pair of big mass repulsers where the gasbags had been back in the olden days.