Windmill
A wind water mill is a combination of a water mill with a windmill attached . Condition is a suitable location with strong enough flowing water for permanent operation of the watermill and enough wind days to drive the windmill throughout the year. These conditions and the high construction costs for two mill buildings with two primary drives ( impeller , impeller shaft with comb wheel and water wheel with shaft and comb wheel) severely restricted the spread. Both drive parts - the impeller shaft of the windmill and the shaft of the water wheel - attacked the common vertical shaft . This transmitted - depending on the circumstances, either driven by the wind or the base load by water - the mill. For example, if hydropower was reduced in dry summers, the windmill could take over; conversely, on days with little wind, hydropower could drive the mill. Most of these mills were built as an extension of an existing water mill to a double mill in the 19th century, and they were mainly in Lower Saxony ( Hanstedter Mühle), Schleswig-Holstein (Oster Husumer Mühle, Köhner Mühle) and North Rhine-Westphalia . In Germany, two mills of this rare design are worth mentioning, in Emsland the Hüvener Mühle from 1554 (water mill) and 1802 (expansion to a double mill, the only completely preserved mill of this type in Europe) and in North Rhine-Westphalia in the Minden-Lübbecke district the monastery mill in Lahde (Windmill attachment from 1876 on the watermill building documented in 1292; Westfälische Mühlenstraße ).