|John Whitehurst, Joseph-Michel Montgolfier mechanics|
Momentum of water whose flow, cyclically closed, rams water past a check valve up a hill, and regulates itself as the waste valve is first closed by the flow and then opened as it falls.
Pulsation engine Self-acting ram pump Water hammer Water ram Hydrolic ram Hydram operates with only water flow— look Ma, no hands.
Water rushes down the pipe and THUMP past the check valve and up toward the attic of the house. Before electricity came to the farm and THUMP water users had to make clever use of gravity.
Joseph-Michel Montgolfier and his brother Jacques-Étienne owned a paper mill in Voiron and developed the first manned untethered flight of a hot-air balloon. The balloon was made of paper. Joseph-Michel invented the first self-acting water ram to raise water at their paper mill. Early water rams cycled every minute or so, producing a loud thump with each cycle.
See also in The book of science:
Readings in wikipedia: