while reading about the economic developement of Medieval Europe I came upon this interesting fact.



"The camshaft is one of those little, completely anonymous technical marvels that changed the history of the world. Although there were possibly Greek/Roman, Chinese and Islamic precursors, the development of the crank and the camshaft are generally believed to be among the greatest contributions of medieval European technology.

Cams are lobes or projections on a rotating shaft and are used to transmit a motion at a predetermined time during the rotation of the shaft. In particular, cams translate a rotating movement into a reciprocal movement (up and down or back and forth), or on the following picture (courtesy Scientific American):



The medieval development of camshafts has proven to be of immense technological significance. It allowed the budding medieval industry to transform the rotating movement of waterwheels and windmills into the movements that could be used for the hammering of ore, the sawing of wood and the manufacturing of paper. Especially after having been powered by the developing windmill technology, this led to the first industrial revolution in the Low Countries. Since then, the camshaft (together with the crank and toothed wheels) has been among the key parts of all (semi-)automated processes, up to the functioning of the valves in the engine of your car.