ABSTRACT
One might well suppose that, in the transition from the Vitruvian water-mill to the post-windmill as we know it, there would have been an intermediate stage with the stones placed above the main driving-shaft; in effect a water-mill on stilts with windmill-sails substituted for the water-wheel. Further incentives to the use of tower-mills may well have been the scarcity of sufficiently massive timber for the construction of post-mills, and the desirability of erecting windmills on the walls of towers and castles. The mechanician Ramelli in 1588 is the first to depict the internal working parts of windmills; he shows both post- and tower-mills for grinding corn. The fact that the windmill was becoming fairly commonplace in the late 13th century is consistent with a first reference to it about a century earlier. Early references describe a windmill specifically as molendinum ad ventum, other mills being known simply as molendina.
