Tantalus Cup, A Self-Siphoning Cup That Can Never Be Filled. The Tantalus Cup Helps Demonstrate Pascal'S Principle, Or How A Siphon Works, Each

Details:

A glass cup with a u-tube attached when water reaches the top of the inverted u-tube, a siphon action begins which drains the water until the end of the u-tube is exposed when the cup is filled with water, the water is forced up the inverted u-tube so that equilibrium is maintained in the cup as the water level reaches the top of the u-tube it is begins to fall through the siphon as the water falls, it creates a vacuum which causes more water to be forced into the tube