Barkers mill

from The Collaborative International Dictionary of English v.0.48

Barker's mill \Bark"er's mill`\ [From Dr. Barker, the inventor.]
   A machine, invented in the 17th century, worked by a form of
   reaction wheel. The water flows into a vertical tube and
   gushes from apertures in hollow horizontal arms, causing the
   machine to revolve on its axis.
   [1913 Webster]