Put the empty bottle and balloon in your
refrigerator. Leave them there for at least one hour. They both must be
Before removing the bottle and balloon from
the refriger- ator, prepare the buckets of hot and cold water. Add a handful
of ice cubes to the cold water to make it colder.
Taking the balloon in your hand, squeeze
it to drive out any air it may contain. Then quickly slip the neck of
the balloon over the mouth of the cold bottle.
Immerse the bottle in the hot water (itís
okay if the balloon is in the water too). In a few minutes, youíll see
the limp balloon begin to inflate.
When the inflation stops, immerse the bottle
in the cold water. The balloon will slowly shrink and become limp again.
Repeat the hot and cold immersion steps.