We understand by tidemills those that use the flow and
ebb tide of the marine water for their drive. The mills that act with
the force of the water base their system on the impulse of a mass of
water on an impeller wheel that when turning moves a stone tooth,
which is located on another fixed resemblance but, that crushes the
grain introduced between both. The water tank that they have,
denominated " antepara "(pond), guarantees the availability of the water to
be able to grind during two daily cycles of seven hours.
The first trustworthy data on a tide mill takes us locality
to the English of Dover, mill that was constructed between years 1067
and 1082. From then an increasing increase of these mills in the
coasts of England is appraised.
In the documentary news gathered on mills, it is appraised that the first tidemills known in the gulf of Gascugna are dated in century XII, and later they are those of Portuguese, Bizkaia, Gipuzkoa, Galizia and coasts.
In sum, them date of construction of the first tidemills they go back to century XI in England, and with the passage of time it is extended east type of construction towards the south until arriving at Portugal, where also they were abundant. He is reasonable, therefore, to establish the theory that the construction teachers of the North part of Euskalerria, " gascones ", were in charge to show the complex technique of construction of mills of tide their brothers of the south, the " vizcaínos ", transmitting itself by this knowledge to the rest of the Iberian Peninsula.