Actuation of the piston heads serves to force water under pressure through a suitable discharge pipe to a remote location such as a reservoir where the water can be converted into {HEAD ~ a usable form} of {TAIL ~ energy} 
of
Actuation of the piston heads serves to force water under pressure through a suitable discharge pipe to a remote location such as a reservoir where the water can be converted into { HEAD ~ a usable form } of { TAIL ~ energy }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL