Sweet girl did this experiment to study how clouds form. She used a glass jar, about 50 ml of hot water, a match, and a plastic bag full of ice cubes. We added the hot water. Then lit the match and held it over the jar of hot water. Next, we dropped the match in the jar and quickly covered the top with the bag of ice cubes. Quickly a "cloud" began to form inside the jar.
Silly guy proving air has pressure.