Date: 1886
Their power was derived from a column of water which gave a reciprocating action to a piston.  For a long time they were used exclusively as pumping engines, but more recently the reciprocating action has been converted into a rotary movement ; and it is possible that they may be turned to many services where a high level water-supply exists, and there is a demand for limited quantities of power.  * * Karmarsch : Gesch.