Ship mill

The ship mill is an ancient type of watermill that was a familiar sight on French waterways until the mid-19th century. In the late Middle Ages there were more than fifty-five in Paris, on the Seine between the Île Saint-Louis and the Pont au Change, moored to the city’s bridges by long hawsers. The river’s current drives the waterwheels on either side, which transmit the energy produced to the grinding mechanism on board the vessel. The two-wheel mill was rivalled by its more stable and more efficient cousin, the single-wheel, twin-hulled mill. The development of river trade and the advent of steam-powered craft rang the death knell of this archaic form of milling, which hindered river traffic. This model is similar to the illustration of ship mills reproduced in Diderot and d’Alembert’s Encyclopédie, except for the frame and the break boards upstream of the waterwheels.