Purpose:Demonstrate the role of atmospheric pressure in the operation of a drinking straw.
Description:The initial configuration of the water in the bottles is seen in the photograph at the left above. When air is pumped out of the bell jar, water flows through the tube from the stoppered bottle into the open bottle, as seen in the photograph at the right. When air is allowed to flow back into the bell jar, the water flows back into the closed bottle, reproducing the initial water configuration.