The daily grind?

Louring skies behind Lochnellan on Dava Moor where we spotted what appeared to be a giant cow pat. The circular granite stone is lying in the grass behind the steading and has a diameter of about 18 inches. We assume it to be a form of quern or grindstone probably used for grinding small quantities of corn to produce oatmeal - hence the daily grind.

Can anyone shed light on this?

I have since learned that this is almost certainly the base of a rotary quern and, being large, may actually have been operated using an animal. Landowners disliked tenants using querns because they enabled the owner to avoid taking grain to the mill where a tax (thirlage) was payable. Lairds sometimes sent out search parties to find and destroy querns.