SM206      Water Hammer Demonstration    circa 1950     Hydrostatics

  This demonstration apparatus consists of a glass tube partly filled with water but which is evacuated before being sealed off.   When this tube is suddenly inverted the water inside falls in one undivided mass against the opposite extremity of the tube producing a sharp dry sound resembling that coming from the impact of two solid bodies.

  So the demonstration shows clearly the effect on a liquid when the presence of air that positively affects by opposing its fall is eliminated.   The air would break up the water into droplets and show up as the effect of a waterfall where much of the water finishes as small drops or even a fine mist.