Macroeconomic hydraulics or hydraulic macroeconomic model is still being constructed and reconstructed in order to satisfy different purposes. The intensity of such construction and reconstruction was spectacular after the publication of The General Theory (1936) by John Maynard Keynes. Owing to its "revolutionary nature," The General Theory has converted "Keynes" into "Keynesian revolution" and "Keynesianism". The diverse versions of Keynesianism have been classified byCoddington (1976, 1983) into the three categories: (a) Hydraulic Keynesianism, (b) Fundamentalist Keynesianism, and (C) Reconstituted Reductionism (or Disequilibrium Keynesianism). by analogy of "hydraulic Keynesians, " Philips (1950) constructed hydraulic macroeconomic model, and later on, with the collaboration of Newlyn, Philips also constructed the Newlyn-Philips real hydraulic machine. But the question is - who is the originator of the hydraulic macroeconomic model? Some literatures indicate that an American economic Irving Fisher was the inventor of hydraulic macroeconomic model. The present paper sheds light on this area.