The last miller at Bourn was George Papworth, whose father was the landlord at 'The Fox' in Bourn. Bourn Mill is a type of mill called an 'open trestle post mill'. The buck has two floors. The upper stone floor contains the grinding stones which rotate against each other to grind grain. The upper or runner stone is turned by energy provided by huge sails, harnessing the energy of the wind.
Grain is poured from a hopper into the gap between the stones and is ground into flour.
A chute carries the flour down into the meal bins on the lower floor. The sails have to face squarely into the wind and in order to achieve this the whole body of the mill, with all the machinery inside has to be rotated around the central post using the tail pole. To stop the sails, the mill must be turned again so that they are 'on edge' to the wind. In violent storms the miller must carefully judge the position of the sails to prevent them pulling on the wooden gears and brakes, which might lead to fire through friction. Fire is a big risk in wooden mills.