Abstract: An improved scoop is usable in combination with a wheel providing a rotating peripheral surface with an annular body of liquid supported on that surface and rotating with the wheel. The improvement comprises:(a) The scoop projects partially into the rotating annular body of liquid;(b) The scoop is mounted for rotation about an axis and in a forward direction in response to force transmission to the scoop from liquid entering the scoop;(c) The scoop has an interior surface that is locally curved to turn the entering liquid for discharge from the scoop in a relatively rearward direction; and(d) Substantially the entirety of the scoop interior rearwardly of said interior surface is rearwardly open to the exterior.