Fluid operated rowing machine

Claim 1

IN A ROWING MACHINE OF THE CHARACTER HAVING A PAIR OF OAR SIMULATING ELEMENTS WITH HAND GRIP PORTIONS AT THEIR INNER ENDS AND MEANS MOUNTING SAID OAR ELEMENTS AT THEIR OUTER ENDS TO SWING ABOUT AXES TO SIMULATE OAR STROKE MOVEMENT AND OAR LIFTING AND FEATHERING POSITIONS, THAT IMPROVEMENT COMPRISING A CLOSED DOUBLE LOOP, FLUID-FILLED HYDRAULIC PIPING SYSTEM, A PISTON IN EACH LOOP OF SAID SYSTEM ACTUATED BY A SAID OAR ELEMENT FOR INITIATING FLUID FLOW AND CIRCULATION IN SAID LOOP WHEN SAID OAR ELEMENT IS SWUNG ABOUT ITS SAID AXIS TO SIMULATE AN OAR STROKE MOVEMENT, FLUID DRIVEN INERTIA MEANS IN SAID SYSTEM COMMON TO BOTH SAID LOOPS SUSTAINING FLUID FLOW AND CIRCULATION IN SAID SYSTEM WHEN ONCE INITIATED BY A SAID PISTON, SAID MEANS NORMALLY CONTINUING TO APPLY FLUID PRESSURE IN BOTH LOOPS OF SAID SYSTEM THROUGH SAID PISTONS AGAINST SAID OAR ELEMENTS IN OAR STROKE MOVEMENT DIRECTION, NORMALLY CLOSED VALVE MEANS IN EACH SAID LOOP BYPASSING THE RESPECTIVE PISTONS IN THE LOOPS, AND MECHANISMS FOR OPENING SAID VALVE MEANS AND BYPASSING A SAID PISTON IN A LOOP OF SAID PIPING SYSTEM, ACTUATED BY A SAID OAR ELEMENT WHEN SAID ELEMENT HAND GRIP PORTION IS POSITIONED TO SIMULATE OAR LIFTING AND FEATHERING.