Interconnected tube of various elevations with immiscible liquids.

A flexible tube is bent to go through different local minima and maxima and filled with water mixed with fluoresceine for easy viewing. Both ends of the tube are at exactly the same height. Vegetable oil, which is immiscible with water, is added to one end the height of both ends of the tubes adjusts to a new level; but the different density of vegetable oil vs water leads to both sides settling at a different height.