A gas balloon is any
balloon that stays aloft due to being filled with a gas
less dense than air or lighter than air (such as helium
or hydrogen). A gas balloon may also be called a Charlière
for its inventor, the Frenchman Jacques Charles. Today,
familiar gas balloons include large blimps and small rubber
party balloons. Blimps have displaced zeppelins (which
are not balloons) as the dominant form of airship...
