Engineering · a Light

The oldest windmills stood on a plain of constant wind

In Sistan, on what is now the border of Iran and Afghanistan, a wind blows from the north for about a hundred and twenty days each summer, and the mills built there were made for it. They turn on a vertical shaft, sails set like doors inside a walled housing that funnels the wind onto one side of them, with the millstone below. Arabic geographers of the ninth and tenth centuries describe the windmills of the region as a known feature. Mills of the same design at Nashtifan in eastern Iran are still standing and were still grinding within living memory. European windmills, which appear in the records of the 1180s, turn on a horizontal shaft and are a different machine, so most historians treat them as a separate development rather than a borrowing.

Sistan and Nashtifan · attested from the 9th c.