Model 'Comet' corn mill, 1753.
© Science Museum / Science & Society Picture Library
Dr Stephen Demainbray (1710-1782), the famous lecturer, had this model made while he was in Lyon, France, in 1753. The mill from which it was copied had been designed a few years earlier by M Dubost to operate on the river Rhone. The mill was situated in a boat which was moored in the current. The flow of water turned the archimedean screw propeller which turned the upper grinding wheel underneath the roof.