A watermill is a structure that uses a water wheel or turbine to
drive a mechanical process such as flour, lumber or textile
production, or metal shaping (rolling, grinding or wire
drawing).
In ancient Mesopotamia, irrigation machines are referred to in
Babylonian inscriptions, but without details on their construction,
suggesting that water power had been harnessed for irrigation
purposes. The primitive use of water-rotated wheels may date back
to Sumerian times, with references to a "Month for raising the
Water Wheels", though it is not known whether these wheels were
turned by the flow of a river.
The earliest clear evidence for the use of water for powering
mills dates back to the ancient Greco-Roman world. The British
historian of technology M. J. T. Lewis has shown that portions of
Philo of Byzantium's mechanical treatise, which describe water
wheels, and which have been previously regarded as later Arabic
interpolations, actually date back to the Greek 3rd century BC
original. The Greek author Strabo mentions in his Geography another
early watermill, located near the palace of king Mithradates VI
Eupator (r. 120-63 BC) at Cabira. In the early 1st century BC, the
Greek epigrammatist Antipater of Thessalonica made the first clear
reference to the waterwheel which he praised for its use in
grinding grain and the reduction of human labour.
By the early 20th century, availability of cheap electrical
energy made the water mill obsolete in developed countries although
some smaller rural mills continued to operate commercially into the
1960s.
The rural communities of Trás-os-Montes still use community mills
although many are obsolete and abandoned to the fate and the
elements.
