Perpetual motion: A grinding mill M, driven by a water wheel H, which is itself driven y waer from upper cistern F. In addition to driving the mill, the whater wheel also drives the water up again to the cistern by rotating the Archimedean screw Q, and the pumps B and C. Engraving from Theatrum Machinarum Novum by George Andreas Bockler (Nuremberg, 1673).