ROMAN PINWHEEL MILL 

This model shows an earlier method of gearing where pegs are inserted in the gear wheels in order to connect with the lantern gears which turn the stones above. A lightening lever can be seen below each of the lantern shafts, this is used to make the adjustments of the gap between the millstones by raising the top stone a fraction using wooden wedges under the levers at floor level 

 Looking down through a cutout in the roof shows the mill has two stones, the floor is also cut away so the mechanism below is visible to visitors to the museum

The main gear here shows the wooden pegs that connect with the lantern gears to turn the stones up above. Also visible is the lightening rod which sets the gap between the stones.

The millwheel is undershot and runs down anarrow channel and under the pathway at the side