Millstone at Slaughter farm (3)

Image: © Nigel Mykura Taken: 2 Jul 2012

Millstone at Slaughter farm (3) This converted farm has eight old mill stones built into the wall that runs along the road outside. This is the third millstone from the gate and shows a French burr stone, one of six such stones in the wall. Stones like this were made from a Triassic Period freshwater quartzite stone that was quarried at La Ferte sous Jouarre near the town of Chalons in the Marne Valley in Northern France. The stone from this district was acknowledged the world over to be the finest stone for making millstones. This fame was based on the stones hardness and its ability to grind much whiter flour that other stones used to manufacture millstones. It did this by not breaking the bran of the wheat down to small particles but leaving them as large flakes which could then be separated from the flour producing a white flour. With inferior quality millstones, the bran is ground down to a much smaller size which cannot then be separated from the flour and gives it a darker appearance. This superior quality is partially due to the fact that the French burr (sometimes known as buhr) stone has a large number of natural pores of varying size which are exposed during grinding and which have very sharp edges allowing the stone to cut the wheat rather than just grind by abrasion. Although monolithic Frech burr stones are known, they are very rare outside France and most burr stone millstones are manufactured from small lumps of stone from the French quarries. These stones would be imported as lumps of rock and would then be manufactured into mill stones in small factories of which there once quite a large number in England. The fragments are held together by plaster of paris and iron bands round the circumference of the wheel. It is very easy to recognise a French Burr stone from these visible pores and the fact that the stone is made up from fragments fitting together like a jigsaw. Both these details are visible on this stone. Occasionally the centre of a burr stone millstone would be made from a cheaper stone such as millstone grit because it is on the outer part of the wheel that the flour is mainly ground. This wheel appears to be made entirely from French burr stone. The arrangement of the lumps of burr stone within the millstone tends to be a circumferential layer with rounded outer edges on the perimeter of the stone and a central section often roughly square in shape. This millstone has nine lumps of burr stone in the circumferential section and four lumps in the central section making a total of 13 in all. The closest mills to the farm are on the River Windrush, one is at Aston farm at SP 1497 2134 about 1km away and the other at Bourton on the Water at SP 1631 2082about 0.5 km away. Whether these stones came from either of these mills or elsewhere is unknown. It is unlikely that a single mill would have six burr stone wheels so they probably came from different sources

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