Introductory

Mills occupied a predominant position in the medieval economy. They were used initially and primarily for grinding grain, but as techniques developed they were also employed for other purposes, such as pumping water, fulling cloth, smelting metal and sawing wood. The prehistoric method of grinding grain was in a quern: a rounded stone was rubbed up and down on a slightly hollowed lower stone sloping away from the operator. But in the later prehistoric period the rotary quern became the principal tool for grinding grain. This comprised two millstones, the upper (the ‘runner’) and the lower (the ‘bedstone’). The runner had an upright wooden handle inserted in it, which the operator held to rotate it over the bedstone. Handmills of this basic kind survived from ancient times and through the classical and medieval periods into the modern era. Because, although laborious to use, they were cheap, and conducive to social independence and self-sufficiency, they were never totally replaced by technologically sophisticated mills. In the latter the runner stone was rotated by elaborate machinery powered in various ways, occasionally by horses, oxen or even men or women, but most often by water or, alternatively by the wind: as we shall see, in the middle ages wind-power was first harnessed to work the mill machinery rather later than water.

The essential component of a watermill was a waterwheel turned by the force or weight of water. There were various kinds of waterwheel common in medieval England. They were vertical wheels, the most efficient of which was the overshot wheel. This was turned by water falling on it from a trough just left of dead centre of the top of the wheel which had paddles or buckets on it – if paddles, it was the force of the water which turned the wheel, and if buckets, it was the weight of the water. Another common type of wheel was the breastshot (also the ‘half’ breastshot and the ‘low’ breastshot). This was turned by water falling on the wheel at a point level with its axle (or lower). Yet another type was the undershot wheel which was turned by water striking it underneath. Although the overshot wheel was the most efficient, it depended on a fall of water of at least eight feet.