Editing Water wheel (section)

=== India ===
The early history of the watermill in [[History of India|India]] is obscure. Ancient Indian texts dating back to the 4th century BC refer to the term ''cakkavattaka'' (turning wheel), which commentaries explain as ''arahatta-ghati-yanta'' (machine with wheel-pots attached). On this basis, [[Joseph Needham]] suggested that the machine was a [[noria]]. Terry S. Reynolds, however, argues that the "term used in Indian texts is ambiguous and does not clearly indicate a water-powered device." Thorkild Schiøler argued that it is "more likely that these passages refer to some type of tread- or hand-operated water-lifting device, instead of a water-powered water-lifting wheel."<ref>Reynolds, p. 14</ref>

According to Greek historical tradition, India received water-mills from the Roman Empire in the early 4th century AD when a certain Metrodoros introduced "water-mills and baths, unknown among them [the Brahmans] till then".<ref>{{harvnb|Wikander|2000|p=400}}: {{blockquote|This is also the period when water-mills started to spread outside the former Empire. According to [[Cedrenus]] (Historiarum compendium), a certain Metrodoros who went to India in c. A.D. 325 "constructed water-mills and baths, unknown among them [the Brahmans] till then".}}</ref> Irrigation water for crops was provided by using water raising wheels, some driven by the force of the current in the river from which the water was being raised. This kind of water raising device was used in [[History of India|ancient India]], predating, according to Pacey, its use in the later Roman Empire or China,<ref>Pacey, p. 10</ref> even though the first literary, archaeological and pictorial evidence of the water wheel appeared in the Hellenistic world.<ref name="Oleson 1984, 325ff.">{{harvnb|Oleson|1984|pp=325ff.}}; {{harvnb|Oleson|2000|pp=217–302}}{{page range too broad|date=January 2022}}; {{harvnb|Donners|Waelkens|Deckers|2002|pp=10−15}}{{page range too broad|date=January 2022}}; {{harvnb|Wikander|2000|pp=371−400}}{{page range too broad|date=January 2022}}</ref>

Around 1150, the astronomer [[Bhaskara II|Bhaskara Achārya]] observed water-raising wheels and imagined such a wheel lifting enough water to replenish the stream driving it, effectively, a [[perpetual motion]] machine.<ref>Pacey, p. 36</ref> The construction of water works and aspects of water technology in India is described in [[Arabic]] and [[Persian language|Persian]] works. During medieval times, the diffusion of Indian and Persian irrigation technologies gave rise to an advanced irrigation system which bought about economic growth and also helped in the growth of material culture.<ref>Siddiqui</ref>