The mill is a sistem exploiting the energy produced by water to grind cereals and sometimes for other purposes. This energy depends on various elements, such as:

The formula P=Q·H·n estabilishes a relationship expressing the power caused by the flow and the consequent fall . Mills are never directly moved by the river by which they are bulit but they receive water through a ditch regulating the water flow.

Near the mill the water falls shortly transforming its potential gravitational energy (U=m·g·h) into mechanical energy (E= ½ mv² ) thus producing work. The width of the ditch can be reduced by a system of bulkhead inserted in a blockage wall consisting of stone put together with cement. The mill is also protected by a grate preventing objects from damaging it.

There are two types of water works:

1 HORIZONTAL-WHEEL PLANT: this plant is diffused along streams and little rivers. This system is economical and requires a low-cost mantainance.

2 VERTICAL-WHEEL PLANT: this type is more common in plain. This system consists of gears multiplying the power of the millstones

The task of the mill was to facilitate the farmer’s work in different areas, such as grinding the corn, weaving and production of the oil and wine, metal working and milling a phase in the wollen cloth working process, which differed according to the product to be processed. The function can be clearly understood by observing the drawing A and B.

Here there ‘s the description of the structure and the use of one of these machines for the corn grinding.

The is initially put into the hopper, an element made of wood with shape of truncated pyramid upside down. The two square bases of the hopper, the larger of which is about 50 centimetres per side, the other 20 centimeters per side, are open .

Through the former the corn is poured, its fall is regulated by a slide and finally it gets into the millstones.

The corn fall is maintained regular thanks to a special wooden stick which shakes the slide to avoid its stopping. Now the corn is between the millstones, two stones one above the other, 10 or 20 centimetre high, usually framed in iron. We can distinguish two different kinds of them:

In order to avoid the wear and tear of some parts of the mill and the unbalacing ofmillstones, the mill needed an accurate maintenance to guarantee the best grinding efficency. The maintenance of the millstones was the most complex job due to their dimensions and their weight ( 120-130 cm x 400-700 kg).

For this purpose a machine called pinch bar was used. It consists of a vertical metallic or wooden beam and two semi-circuled metallic arms with pivots at their extremes to be inserted into the holes at the edges of the millstone and allow its movement.

At this point it was possible to reestablish the flutes thanks to a small short-handled pick.

The new surface had to be levelled again to be able to work without any sort of unbalance. The spiral flute was engraved again: there were two kinds of surface; a smooth one and another inclined. The former was hit with the bushhammer suitable for knurled surface, the latter was treated with a percussion hammer from the edge to the centre.

After the restoring work the millstone had to be replaced in its original site guaranteeing a perfect balance on a single pivot by means of molten lead which filled holes previously engraved on the superior part of the millstone.