Stock Photo: Draining a mine using a duplex suction pump. The box ABCD, shown in detail on the right, contained the crank which operated the piston. From De re metallica, by Agricola, pseudonym of Georg Bauer (Basle, 1556). Woodcut.

Stock Photo: 1746-1923 Draining a mine using a duplex suction pump.  The box ABCD, shown in detail on the right, contained the crank which operated the piston.  From De re metallica, by Agricola, pseudonym of Georg Bauer (Basle, 1556).  Woodcut.