Ann Lee looks at the mechanics of grinding corn
Image: Owen Llewellyn
Have you ever put your 'nose to the grindstone' when you had a difficult task to do? This is a picture (right) of the large Derbyshire greystones at Brixton Windmill, which were once used to grind grain. Beside them is the complex arrangement of gears which connects them to the main shaft, driven by the wind.
Mill expert David Nicholls explains: "There's a lot that can go wrong when the corn is being ground. An apprentice would have to sit beside the stones and check that there was a steady supply of grain between the stones (or 'grist to the mill')."
As we all know, the speed of the wind can vary a great deal - and with it the distance between the 'runner' (the top stone that turns) and the 'bedstone' (the base stone that remains static). Between adjusting the sails and checking the regulation of the stones, the miller and his apprentices would have had a constant task to ensure that the stones did not jam up with too much grain or run dry, striking sparks off each other. It was also important to ensure a constant feed of grain into the hopper above the stones, and into the shoe which guides the grain into the stones.
The millstones at Brixton Windmill are made from a hard and coarse-grained gritstone found in the Peak District, a form of sandstone - the most commonly used material for millstones at the time. Cut from one piece of stone, they would wear quickly and require regular dressing.
Image: Nick Weedon
A bedstone set into the grass outside the door of Brixton Windmill shows a common version of the many different kinds of pattern into which the grooves, or 'furrows', were cut - grooves which had to be kept very sharp to cut the grain into flour as the stones ground together. This was the job of an itinerant millstone dresser, who often wore the marks of his trade (flying chips) embedded in his arms, and was therefore sometimes asked to 'show his mettle (metal)' as proof of skill at his trade.
To protect the stones and keep the flour inside, the millstones are covered in a removable wooden casing known as a tun or vat. The runner stone and bedstone are slightly convex and concave respectively, with identical patterns on their inner sides which cut into each other in a scissor action as they cross. As the ground flour is channelled from the centre of the stone towards the outer rim, it is picked up by a paddle which pushes it through a chute to the next floor, where it is collected in sacks.
Image: Owen Llewellyn
The stones weigh several tons, and visitors to Brixton Windmill often ask how they were ever raised to the second floor, let alone dismantled for dressing. As you can imagine, lifting stones is a classic feat of strength, ingenuity and accuracy, involving a variety of cranes and hoists. For dressing purposes, a temporary 'scissor grip' crane is used to lift and turn the stone. A variety of pegs, wedges and pulleys may also have to be brought into play.
At Brixton Windmill there were originally two pairs of stones. Only one pair is now on view, to allow space for visitors. Larger mills would have had up to four or five pairs.
Windmills have been around for hundreds of years, originating in the Middle East. Earlier forms of mill, before wind and water were harnessed to the task, have been with us for much longer - saddlestones and quernstones can still be found in use in some parts of the world.
Wheat has been part of our daily bread for so long that we forget it's not particularly nice to eat raw. So if you have your nose to the grindstone earning your daily crust, perhaps it's time to give thanks for the wind and weather that allowed your ancestors to make theirs!