Consists of a glass tube with modifications. Part of the tube before and after the middle is enlarged somewhat, and another U-shaped piece of tube connects the middle to one of these enlarged areas.

A demonstration of Bernoulli's theorem and the operation of a Venturi meter.

• Venturi meter
• Colored water

The U-shaped section of tubing is filled partly with colored water. Air is blown through the apparatus. This produced a pressure differential between the two sides of the U-shaped tube, which causes the water level inside to change accordingly.