Primitive wooden grain wheat thresher
Powered by horse or donkey the threshing board was pulled with usually human weight on it and the marble inserted flints would be cutting the ears of the grain. It was widely used in Europe and this one, called ‘doygeni’ is from a Greek monastery. A little bit of history on old agricultural machinery could be found here: http://thenewinquiry.com/blogs/the-austerity-kitchen/going-with-the-grain/.