Wikipedia talk:Featured picture candidates/Archimedes-screw one-screw-threads with-ball 3D-view animated small.gif

The most practical form of screw is one where the tube rotates with the screw. For lifting water this is essential as it minimizes leaks and all friction between the tube and the screw. I doubt that Archimedes did not understand this but nowhere do I see this depicted in a drawing or description! I would suggest the author revises the animation to show this.