Historical Development of the Windmill - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 5

Figure 1-1. Some concepts of the windmill-like device, or organ, described by Heron
of Alexandria in his Pneumatica , possibly in the irst century A.D. (a) A Dutch-style
rotor driving a disk with four pegs that repeatedly raise the piston in an air pump
[Woodcroft 1851]. (b) The device with a water-mill type of rotor [Schmidt 1899]. (c)
Heron's sketch of the drive, according to Schmidt [1899]. Note the needle bearing ends of
the shaft.