terminating at the top of the vanes 12 the rotor construction is positioned on a base 19 the top of the shaft 13 being positioned as shown protruding through an upper support member 21 to permit rotation of the shaft 13 in use the reservoir is filled as required with a suitable liquid such as water when the rotor 11 is at rest gravity maintains all of the liquid in the lower part of the tubes 18 and the reservoir 17 close to the shaft 13 thereby minimizing the rotor inertia when wind or other driving sources of energy cause the rotor to turn centrifugal force causes the liquid to run out of the reservoir 17 and up the tubes 18 as rotor speed increases the liquid climbs upwardly in the vertical tubes 18 with the resulting weight of liquid equal to the centrifugal force at the base of each tube 18 when the tubes 18 are full centrifugal force holds the liquid therein but the inertia of the rotor 11 has been increased by the weight of liquid moved to the edges of the vanes 12 if the wind should drop and the rotor begins to slow down gravity automatically returns the liquid back to the central reservoir 17 this reduction in inertia tends to maintain the rotor speed similar to the action of an ice skater increasing spinning speed by pulling in his arms in tests we have conducted we have measured the height of the liquid in tubes 18 as a function of rotor speed the theoretical height of the liquid of the vertical tubes is given by the following equation equ1 where h o initial height of water in the reservoir and tubes fig2 shows the results of the.