1851 Great Exhibition: Official Catalogue: Class VI.: Hughes and Sons
From Graces Guide
459. HUGHES and SONS, 1 Great Dover Street, Borough - Manufacturers.
Millstone made of French burrs, with wind-chest and ventilating holes, for grinding with Bovill's patent air-blast, by which the meal is delivered at once from between the grinding surfaces of the stones on its production, and in a cool state, so that it can be dressed as soon as it is ground. The stones, by this patent, grind eight bushels per hour.