This experiment consists of a glass tube that constricts down to a smaller diameter in the middle of the tube. When air is blown through the tube the level of the fluid rises where the air velocity is highest and therefore the pressure is lowest in accordance with the Venturi Effect and based upon Bernoulli's Principle. See more information here: Bernoulli Effect/Venturi Effect Explanation WikiPedia Venturi Effect Explanation WikiPedia Bernoulli Principle Explanation

Equipment
Venturi Tube		Air Hose		Colored Water