The vane has a weight mechanism, for protection in high winds, which automatically turns the mill off by rotating the vane parallel to the wheel. The wind then turns the both the vane and the wheel out of the wind, slowing the mill to a safe speed.

 Later mills had automatic lubrication (and new mills may need no lubrication). This old mill has to be greased by hand, which entails climbing the tower.

Recently in a storm, John Davis realised the automatic safety mechanism was not operating because the blades were rotating so fast they were invisible, like an aircraft propeller. When he climbed the tower to disengage the trapped chain, he was in danger of having his head sawed open. So he descended and invented a long hook which he gingerly used to disengage the chain, while Gail guided him by watching from the side.

There were three sizes: 5 foot, 8 foot and 10 foot, this being an 8 foot mill. Daisy is not named from its flower-like shape, but after Clow's daughter. The mills were Daisy mills, sold to farmers for pumping water to stock troughs. (There was also a Don mill). The water pumps were also made by Clow.  

"Daisy" in USA refers to an air-gun manufacturer. Daisy started in 1882 as Plymouth Iron Windmill Company, however, by the late 1880s the windmill business was changing and the struggling company began looking for new ways to attract customers. They made an air gun which was fired by somebody who said "wow this is a daisy." Probably he said this is a doozy but the daisy stuck. Clow's windmill is no relation to that windmill company!